SMITHSONIAN IWISCELLANEOUS COLLECTIONSVOLUME 81, NUMBER 15 ^ (End of Volume) ARTHROPODS AS INTERMEDIATE HOSTSOF HELMINTHS Chief, Zoological BYMAURICE C. HALLDivision. Bureau of Animal Industry, U. S. Department of Agriculture .H tNST;;m^^ •^>V?f^o'Q.A ri<- (Publication 3024) CITY OF WASHINGTONPUBLISHED BY THE SMITHSONIAN INSTITUTIONSEPTEMBER 25, 1929 SMITHSONIAN MISCELLANEOUS COLLECTIONSVOLUME 81. NUMBER 15(End of Volume) ARTHROPODS AS INTERMEDIATE HOSTSOF HELMINTHS BYMAURICE C. HALLChief, Zoological Division, Bureau of Animal Industry, U. S. Department of Agriculture (Publication 3024) CITY OF WASHINGTONPUBLISHED BY THE SMITHSONIAN INSTITUTIONSEPTEMBER 25, 1929 f/ Z^^c £oti) (^afttmore (prcosBALTIMORE, MD., U. S. i. ARTHROPODS AS INTERMEDIATE HOSTS OFHELMINTHSBy MAURICE C. HALL,CHIEF, ZOOLOGICAL DIVISION, BUREAU OF ANIMAL INDUSTRY,U. S. DEPARTMENT OF AGRICULTUREINTRODUCTIONThe phylum Arthropoda contains numerous forms which serve asintermediate hosts of many parasitic worms, including nematodes,acanthocephalids, flukes, and tapeworms. This fact follows naturallyfrom the fact that the arthropods are an exceedingly large group ofanimals, including the ubiquitous insects and the numerous and widelydistributed crustaceans. It also follows from the fact that these arthro-pods constitute the food supply, wholly or in part, for so many higheranimals, especially for such forms as fish, many amphibians, somereptiles, numerous birds, and some mammals. To a lesser extent itfollows from the fact that in feeding on various plants the higheranimals are certain to swallow the arthropods habitually present on orin these plants. It follows from the fact that many insects feed on orbreed in manure and consequently are exposed to infection from theeggs or larvae of worms parasitic in the hosts responsible for themanure. Last, but not least, the importance of arthropods as inter-mediate hosts of parasitic worms follows from the fact that largenumbers of anthropods, especially the innumerable biting insects,whether transient or permanent ectoparasites, feed on blood and soserve as intermediate hosts of worms which have larval stages livingin the blood of vertebrates.The worm parasites may be classified from one point of view asmonoxenous or heteroxenous. The monoxenous worms have lifehistories in which the worms pass from one host animal to a similarhost animal without the intervention of an intermediate host. Theheteroxenous worms have life histories in which in most cases theworms pass from mature stages in one host animal to larval stages in ahost animal of a dififerent sort, the intermediate host, and then returnto a host animal of the first sort or a more or less closely relatedspecies and develop in this animal to maturity. In some instances twointermediate hosts are utilized in sequence for larval stages.Smithsonian Miscellaneous Collections, Vol. 81, No. 15 (End of Volume)I 2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8lOf the four worm groups named, the cestodes are ahnost exchi-sively heteroxenous. We have the rare exception of Hymenolepisnana of the rat, which develops as an adult in the small intestine ofthe rat, produces eggs which pass out in the feces and by contamina-tion of the rat's food infects the rat with the larval stage of thetapeworm, a small cysticercoid which develops in an intestinal villusof the rat, and which then returns to the lumen of the intestine tobecome an adult worm, the rat serving as both the primary and theintermediate host for the worm. Even in this case it has been claimedthat rat fleas may act as intermediate hosts, but this has not yet beenconfirmed. This may be one of those cases in which a parasite canuse an intermediate host or do without it. We seem to have similarcases in such parasites as the common gape-worm of poultry whichcan utilize the earthworm as an intermediate host or can infectchickens directly, and the blackhead organism which can use thececum worm as an intermediate host or can infect turkeys directly.In the great majority of cases, the tapeworm is adult in an animalwhich eats the intermediate host animal and thereby becomes infestedwith the adult worm as the larval worm from the intermediate hostcomes to maturity in the primary host. In some of the bothriocepha-lids, in cases in which the life histories are well known, the eggs ofthe adult tapeworms present in the primary host, a higher vertebrate,hatch on entering water, infect such small animals as the copepods,and develop in the body cavity of these first intermediate hosts to anearly larval stage, the procercoid. When such infested entomostracansare eaten by such intennediate hosts as fish, the procercoid undergoesfurther development and becomes a plerocercoid in the flesh of thefish. When infested fish are eaten by a suitable higher vertebrate, suchas a human being or dog, the plerocercoid develops to the adult tape-worm in the small intestine of this host.Among the flukes we have one large group, the Monogenea, whichare usually ectoparasitic, mostly on fish, but sometimes endoparasitic,as in the respiratory tract of turtles or the urinary bladder of amphib-ians, and these flukes are monoxenous, developing without an inter-mediate host ; another large group, the Digenea, are regularlyendoparasitic and are heteroxenous. The digenetic flukes occurring invertebrates produce eggs which pass out in the feces or urine andhatch after entering water. Usually the newly hatched worm (miracid-ium) attacks a mollusk host and develops in this host to the stageknown as a cercaria. It may now be eaten by its primary host, or mayescape and encyst in water or on vegetation and be swallowed by itsprimary host, developing in either case to an adult worm, or it may NO. 15 ARTHROPOD HOSTS OF HELMINTHS HALL 3 enter a second intermediate host, an aquatic arthropod or a small fish,and encyst in this host. When such a second intermediate host iseaten by a primary host, the fluke develops to maturity in the newhost.Among the nematodes we have several groups which are usuallymonoxenous, although some of the ascarids, belonging to a super-family, the Ascaroidea, which is ordinarily monoxenous, may beheteroxenous, as in the case of a seal ascarid having a larval stageencysted in fish. One large and important group, the Filariata,composed of two superfamilies, the Filarioidea and the Spiruroidea,is a heteroxenous group with larvae developing in blood-suckingarthropods or in arthropods which feed in some stage of developmenton the feces of the primary host or on food contaminated with thesefeces.Among the acanthocephalids we 'know of the occurrence of inter-mediate hosts, but for the most part we must assume that this is therule, as very few life histories are known in this group. In the knowncases the worm eggs passing from the primary host infect secondaryhosts, develop to a larva and infect primary hosts when these eatinfected secondary hosts, or else re-encyst in another intermediatehost and infect the primary host when it eats the second intermediatehost.The lists of heteroxenous worms and their arthropod hosts, givenin this paper, are the most complete of those published and the omis-sions are probably few. The lists for certain groups have been com-piled from time to time, some of the more important and more recentbeing those of Joyeux (1920), Ransom (1921), \'^an Zwaluwenburg(1928), Seurat (1916, 1919), MacGregor (1917), and Henninger(1928), and, of course, the indispensable catalogues of Stiles andHassall, but no previous paper has attempted to cover all the arthro-pod hosts of the parasitic worms of vertebrates. On the basis of thelists given here this paper includes a consideration of the general factsand of the broad principles which may be derived from a correlationof these facts. While it will serve as a reference for the trainedscientist in the groups involved, its principal value will be as a ref-erence and guide to the younger worker and student and to the manwho works in places remote from adequate library facilities and thespecialized literature on arthropods or parasitic worms. The subjectof the paper excludes from consideration the worms which havearthropods as primary hosts, and the arthropods which are inter-mediate hosts for Protozoa or animal parasites other than the worm 4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8lgroups occurring as parasites in vertebrates. The intermediate arthro-pod hosts are Hsted here as completely as possible ; the primary hostlist is frequently abbreviated to only representatives of groups.In the lists arranged on a basis of parasite groups the names ofhosts are given as they are found in the literature, regardless of spell-ing, synonymy, recognizable status, or validity. This is to enable thereader to trace the records if desired. In the final lists, arranged ona basis of intermediate host groups, the parasites are listed under thevalid names of their arthropod hosts as far as possible. Synonyms ofhost names are indicated as synonyms, but names which cannot berecognized as valid or synonyms are retained. The insect host nameshave been checked by Dr. E. A. Chapin and the late Dr. H. G. Dyarof the Federal Bureau of Entomology through the courtesy of Mr.Harold Morrison, Chief of the Division of Taxonomy, and the crus-tacean host names have been checked by Dr. Waldo Schmitt of theU. S. National Museum, and I wish to acknowledge my indebtednessto these workers for their assistance.ARTHROPODS AS INTERMEDIATE HOSTS OF CESTODESThe known number of arthropods acting as intermediate hosts fortapeworms is so small that this subject can be covered rather compre-hensively. At the same time, one must generalize here as elsewhererather carefully, since we know the life histories of only about i percent of the known tapeworms. In addition to arthropods, the inter-mediate hosts of tapeworms include mammals, birds, reptiles, am-phibia, fish, mollusks, annelids, and other animals. In all probabilitymany worms now known only as having one intermediate host will befound to require two successive intermediate hosts. The followinglist will show the tapeworms, their primary hosts, and their inter-mediate hosts, for such tapeworms as have arthropods as intermediatehosts. ANOPLOCEPHALIDAE It is Still true that the life histories of the anoplocephaline tape-worms are unknown. The larval cestode which has been reported fromAphodiiis obscurus and tentatively referred to Cittotaenia marmotaehas not been definitely coupled with that worm by the test of success-ful feeding experiments, and the record is of value primarily as apossible clue to solving the unknown life histories in this group. NO. 15 ARTHROPOD HOSTS OF HELMINTHS—HALL oU J U no -8o. oa. oU S « ^ « g a -« ^ o o Ho G ci, Si 5 ^ ^ V. o E-x Sh L) t-^ -SOSo >< 'o (X, to, >^ C4 .S rtU P-( Cl, Pi CL, ^ 3 ^1 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l u I NO. 15 ARTHROPOD HOSTS OF HELMINTHS HALL '^ fn '^ S: -Cv. -Ci, -ft, -Ci, -Ci. 13O C) O O Ci »-Q U to 'o ^.^"^ "2 "2B 5 U U < O 9 -S'-d : .. U H O •i 2 oj 5j 5° «15 3 ^ ^u H O ex. a^^ 2 ~ -^ V2 S -^ "-J s- .c 2 -^•i; ^ s s C •^ >~J ^ X U Cl f- ex. CL 2 ^ NO. 15 ARTHROPOD HOSTS OF HELMINTHS HALL II U 12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8 1 coU U ^ NO. 15 ARTHROPOD HOSTS OF HELMINTHS—HALL 13 T30.V 14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l =^ _ D.u C' U O U O u -i: -r e -i ~ -2 = ^ ^ Q Q u ^ j: ^hJ V 2 2 ^ ., o ^j >^ _^ W vj '-'§ S" "S S" "5 s^u to Lj aO ^ w S we " « " NO. 15 ARTHROPOD HOSTS OF HELMINTHS HALL I5HYMENOLEPIDIDAEThe hymcnolepicl tapeworms are predominantly parasitic in birds,the above Hst of species with known life histories including 22 speciesin birds and only 6 in mammals. An inspection of the intermediatehosts for hymenolepids in mammals shows that they include membersof the Coleoptera, the Siphonaptera, the Mallophaga, Lepidoptera,Dermaptera and the Myriapoda, of which the Coleoptera seem atthis time to be somewhat the more important. In the case of onetapeworm, Hymenolepis diminuta, members of all the groups named,with the exception of the Mallophaga, can function as intermediatehosts, but such a wide range of intermediate hosts is rather unusual.In no case does the intermediate host appear to depend primarilyfor its function as host on a role as food for the primary host, butrather on the chance of being swallowed accidentally as a contam-inating element in food, or occasionally on the fact that such primaryhosts as dogs will root out and swallow the fieas which are annoyingthem. Of the 3 species of hymenolepids infesting man, all are par-ticularly likely to occur in children, largely because children are lesscareful in their food habits and in matters of personal cleanliness,and are more disposed to be intimate with such tapeworm hosts asdogs and cats.When we consider the hymenolepid tapeworms of birds, the case issomewhat clearer as to the predominance of certain arthropod groupsas intermediate hosts and the reason for this predominance. TheEntomostraca, especially the Copepoda, are very decidedly the pre-dominant group of intermediate hosts known at present for hymeno-lepids in birds. The birds in these cases with entomostracan hosts arepractically all members of the Anseriformes and the role of inter-mediate host in these cases is clearly also that of food for the primaryhost. The exceptional cases, such as that of the green pigeon as a hostfor Hymenolepis gracilis, or the chicken as a host for Fimhriariafasciolaris, must be explained as probably due to accidental swallowingof an intermediate host. One can say from the available facts that theintermediate host of a hymenolepid in anseriform birds should besought among the Entomostraca and that the chance of entomostra-cans being the intermediate hosts is very great. The one case of amalacostracan, Potamohius astacus, as a host of a hymenolepid,Hymenolepis collaris. occurring in anseriform birds is regarded byRailliet as doubtful, and in general the larger Crustacea are not yetincriminated as intermediate hosts of avian tapeworms. l6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8lAs regards hymenolepid tapeworms occurring in the Galliformes,the intermediate hosts shift naturally to the insects, the Coleopteraand Diptera standing close together in importance at this time. Thereports to date indicate that at least two tapeworms, Hymenolcpiscarioca and Choanotaenia infundihulum, can utilize members of bothof these insect groups as intermediate hosts, and that the beetle hostof C. infundibulmn will also' serve as a host of H. serpentulus, the lat-ter usually a parasite of passeriform birds. The role of these insectsas intermediate hosts of tapeworms of galliform and passeriformbirds follows from their role as food for these birds and from the factthat the beetles feed on excrement and the stable flies breed in strawwhich is readily contaminated with excrement. Aside from anthropods,the intermediate hosts of hymenolepids include such forms as earth-worms and leeches.Stafford (1927) reports in a preliminary note that a number ofAmerican amphibious insects serve as intermediate hosts for variousflukes and for hymenolepid tapeworms. The record of these tape-worms in more definite form has not yet come to the attention ofthe present writer. DAVAINIIDAEThe known life histories of tapeworms of the Davainiidae coverforms parasitic in birds and incriminate flies as intermediate hosts,the common house fly being reported as the host for Davahiea tetra-gona and D. cesticillus. The possible role of ants and grasshoppersas intermediate hosts for D. friedhergeri is noted in the literature buthas only the value of a surmise and has not been included in the listof hosts. Diptera would appear to be especially promising among thearthropods as intermediate hosts of davainid tapeworms, but theseworms also utilize such intermediate hosts as snails and slugs, asidefrom arthropods, and the total number of known life histories doesnot warrant much generalization.AMABILIIDAEThe only known life history for a tapeworm belonging in the Ama-hiliidae is that for Tatria acanthorhyncha, and this involves theOdonata or dragonflies as intermediate hosts. The only genera otherthan Tatria assigned to this family by Ransom are Amabilia andSchistotaenia, but until we have more information as to life historieswe cannot assume that the Odonata have special importance as inter-mediate hosts in this family. In the one known life history, the dragon- NO. 15 ARTHROrOD HOSTS OF IIELMTNTIIS HALL I7 fly evidently plays the role of host for the tapeworm and food for theralliform bird host. PROTEOCEPHALIDAESo far as final hosts and intermediate hosts are known, the cope-pods are outstandingly important as intermediate hosts of proteo-cephalid tapeworms in fish, the Cladocera serving as hosts in only onecase. Apparently these tapeworms form a procercoid in the entomos-tracan host, and this develops to a second larval stage in small fish orother suitable hosts, and then to an adult when this second inter-mediate host is eaten by a suitable primary host.DIPHYLLOBOTHRIIDAEIn the Diphyllobothriidae we have tapeworms in which the lifehistory sometimes, though apparently not always, involves two inter-mediate hosts. For the known cases, the first intermediate host isalways an entomostracan and the second intermediate host is a fish.The known entomostracan hosts are copepods. Since the role ofintermediate host played by entomostracans in these life cycles isevidently based on the role of Entomostraca as fish food, it is obviousthat the Entomostraca would be first choice as intermediate hosts ofdiphyllobothrids in a search for the first host, and the copepodswould be first choice among the Entomostraca.RHYNCHOBOTHRIIDAE "The life history is known for only one species of rhynchobothridtapeworm, and in this case decapod crustaceans serve as intermediatehosts. Additional data are needed before one could safely generalizein regard to the intermediate hosts of tapeworms of the family Rhyn-chobothriidae.ARTHROPODS AS INTERMEDIATE HOSTS OF TREMATODESThe following list will serve as a basis on which to draw someconclusions as to the role of arthropods as intermediate hosts oftrematodes. In assigning flukes to various families, the writer hasfollowed various authorities as there is considerable disagreement inregard to the taxonomy of fluke groups, and the arrangement usedwill not meet with anything like unanimous approval. It is onlyintended to serve as a tentative basis for a discussion within the scopeof this paper. i8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l a gQ O H «2 _u5 r "2 Sc^ "^ s 5 S ~ e" 'v 2 S b ^ — .^ t-i eV! t-5 «-; -TS -^ "2s S S S '^^ •":; ^ s >ij p -^ -ti, <;i. g § ^§ 2 2 § -S Q .1 J J U '^ "^ '—* *^ k-^ ^, ^^,. C^ :2 r213 ISS P< < IScuE -b •« -:: -^: .'f r'^ '^ '^ > ^ -" O rtu O fc § s ^^ tl t.CL t. O NO. 15 ARTHROPOD HOSTS OF HELMINTHS—HALL 19 U I u O CS 20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l U h^ NO. 15 ARTHROPOD HOSTS OF HELMINTHS—HALL 21 Q Q u 22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l Q Q •su "o e e 2S 2 ^ 1^ Ci, SO a, a, ci< Co hqfX,, : 26 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l U ^ 3pO NO. 15 ARTHROPOD HOSTS OK HELMINTHS HALL 2"] All analysis of the records given shows the following:PLAGIORCHIIDAEIn the Plagiorchiidae we have a group of flukes which have a widerange of intermediate hosts, including the insect groups Odonata,Diptera, Trichoptera, Plecoptera, Ephemerida, and Coleoptera, andthe crustacean groups, Decapoda and Amphipoda. This range ofintermediate hosts is associated with the range of primary hosts,which include fish, amphibians, and birds. Considered on the basis ofprimary hosts, the plagiorchids in birds utilize Odonata as inter-mediate hosts, those in fish use the Diptera, Odonata, Trichoptera,Plecoptera and Decapoda ; while those in frogs use the Odonata, Tri-choptera, Coleoptera, Ephemerida, Plecoptera, and Amphipoda. TheTrichoptera and the Odonata appear to be the most important inter-mediate hosts. LECITHODENDRIIDAEIn the Lecithodendriidae the insects serve as intermediate hosts andthey include the Plecoptera, Ephemerida, Coleoptera, Diptera, Tri-choptera, Odonata and " amphibious insects." The frog flukes ofthis family use Odonata and Coleoptera as intermediate hosts; thebat flukes use Plecoptera, Ephemerida, Diptera, and Trichoptera.Here also the insects have the double role of intermediate host for thefluke and of food for the primary host.OPISTHORCHIIDAEIn the Opisthorchiidae, insects, specified by Stafford (1927), asamphibious insects, are the only reported hosts. Since this is a largefamily with a wide range of hosts, little of a general nature could beconcluded from the foregoing.ALLOCREADIIDAEIn the Allocreadiidae, parasitic for the most part in fish, the inter-mediate hosts include Ephemerida, Trichoptera, Diptera, and Deca-poda, the more important being the Ephemerida and the Decapoda.The intermediate hosts probably serve as such by virtue of their roleas food for fish. The record for Asfacotrema cirrigerum of a bird asprimary host is found in a footnote reference based apparently oncorrespondence and lacks evidence or detail. 28 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8lGORGODERIDAEIn the Gorgoderidae, commonly parasitic in frogs, the intermediatehosts known at present are mostly Odonata, the role of intermediatehost here being combined with the role of food for frogs. One of theDecapoda, a crayfish, is the host for a gorgoderid parasitic in fish.HALIPEGIDAEIn the Halipegidae, the only reported life history involves theOdonata as intermediate hosts, the primary hosts here being frogs.TROGLOTREMATIDAEIn the Troglotrematidae the only known life history, that of thehuman lung fluke, involves several species of decapods, crabs beingknown hosts and crayfish probable hosts.HEMIURIDAEIn the Hemiuridae, which are fish parasites, all known intermediatehosts are crustaceans, those for two flukes being copepods and thosefor one fluke being decapods.DICROCOELIIDAEThe one dicrocoelid with a known life history utilizes an amphipodas an intermediate host, the primary hosts being fish.BRACHYCOELIIDAEThe one brachycoelid with a known life history has a trichopteranas an intermediate host, the primary hosts being amphibians.FAMILY UNCERTAINThe three flukes of uncertain relationship for which we knowprimary as well as secondary hosts, and not merely secondary hosts forlarval stages, all have carnivores as primary hosts and crabs as sec-ondary hosts.ARTHROPODS AS INTERMEDIATE HOSTS OFNEMATODESIn listing the nematodes having intermediate stages in arthropods,no attention has been paid to nematodes listed only as nematodeswithout reference to whether the nematodes were mature or immature.Nematodes occurring consistently as larvae in insects may be the NO. 15 ARTHROPOD HOSTS OF HELMINTHS HALL 20larvae of worms which will develop to maturity on reaching a suitablehost, although larval nematodes specified as such with no furtherdiscussion may be the larvae of such worms as the mermithids whichwill develop to maturity as free-living forms. In this paper themermithids and gordians are not considered, as they are not regardedas true parasites of vertebrates in the scope of treatment of that sub-ject as limited here. The gordians may parasitize immature frogs inthe course of development of the worms, but this topic is disregardedhere owing to a lack of space for its consideration.All records which are merely surmises to the effect that a certainarthropod is the intermediate host of some nematode are likewisedisregarded. Such surmises have their value in directing exploratoryresearch, but for the purpose of analyzing existing records to obtainvalid data they are worthless. There is sufficient uncertainty in con-nection with a number of existing records to introduce certain ele-ments of possible error as it is.The following list covers the important cases of arthropod hostsfor nematodes. The worms involved fall in the Filariata or Filaridaand most of them fall in the superfamihes Spiruroidea and Filarioidea,two closely related superfamilies which are markedly heteroxenousand hence in sharp contrast with most of the other nematode groupswhich are usually monoxenous. In the exceptional cases in whichmembers of other superfamilies utilize intermediate hosts, the hostsare never arthropods so far as the writer is aware, but are such formsas fish or earthworms. SPIRURIDAEAs intermediate hosts of nematodes of the Spiruridae, which ismade up predominantly of mammalian parasites and to a lesserextent of bird parasites, the Coleoptera are of outstanding importance.In this family the common mode of transmission of the larval wormto the primary host is by means of the ingestion of the secondary host,either as a deliberate act of eating or because of the more or lessaccidental presence of the secondary host in the food of the pri-mary host. In general, dogs, sheep, cattle and horses cannot be calledinsectivorous animals, but the presence of beetles in their customaryfood seems to be sufficiently common to enable various spiruridparasites of these animals to maintain themselves with the aid ofthese beetle hosts. It is evident that some of the spirurids utilizingbeetle hosts may have alternative life histories which are more compli-cated than the mere infection of the beetle host by means of infectiveworm eggs and the infection of the primary host as a result of swal-lowing infected beetles. Thus Seurat has shown that Physocephalus 30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l OU u o CQ 5 a. i: .jj ^ -5 3^ 3^ s «t; CQ ^ O Co U 's S 5 U s ^ E o e Co U ^ U D OQ O^ *^. f^c^ tfi S Q ffi < S Co Co I NO. 15 ARTHROPOD HOSTS OF HELMINTHS HALL 31 ^ g< c9. oQ S V s o V ^5; «a S <-) V FG Q 3 "3 O Gtj ^ « « o -C ^ ^ S «^ ^ S i^^ ^S ^?*^ "3 "^ 'S "S "5 "S '"32 "^ ^ ^ .5 '^ "^^ "^^ "^ "^ "^ "^ "^ "^ •i "^ -2 ^ "^Cl. D_ U « ^ 'vS o 34 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l ta V, g !^ 1:3 "^ -2 •S- s "^h I" ? h i .§:S u G 5 tt: tc = Co s i -; a to «^ <3« 5, s s e•2 -S "2 ^ 5 S: G G Li O D-i »^. »- GoU Oh CLh 3bocD o>'2udu ^ u hooQ O O i^ 42 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l Q U ^ -^ s ?> i? o V o§ S S '5 S £ o G « '^I: ^ -^ -i I -^ § ,..•^^^^^G^^ u GG'^ (^ o ^ « 2•§ "^ u NO. 15 ARTHROPOD HOSTS OF HELMINTHS HALL 43 U S r § u u O Q 9- •S 2 U §.5 -^^ t5to "7 1 t. fc o 5J ^ ^ U A-u u s V S "^=: o S: i-H —< ft! --! rf —H c?U rt o^ f^ D KO. 15 ARTHROPOD HOSTS OF HELMINTHS—HALL 45 sexalatus, a spirurid parasite not uncommon in the stomachs of swineand peccaries, will develop to an infective third-stage larva in itsbeetle host, and when these beetles are fed to some unusual host, suchas rodents, birds, or even cold-blooded animals, the larval worm willre-encyst as a third-stage larva in the unusual host; but if the infectedunusual host is fed to a suitable primary host, the larva will continueits development to maturity. How extensive this device is we do notknow, but it may prove to be a common means of transmitting thespirurid worms of rapacious birds, as Cram has suggested, the spiru-rids of these birds producing eggs which infect some arthropod host,such as a beetle, the beetle being eaten by a small mammal, bird,amphibian or reptile, which is infected in turn with the third-stagelarva, and tlje bird of prey eating these animals and becoming infestedwith the adult worms. The investigation of these life histories is athing on which the mammalogist, the ornithologist, the herpetologist,the entomologist and the parasitologist might collaborate to great'advantage, and the results might show some very interesting andsurprising biological interrelationships.As intermediate hosts of spirurids, the Orthoptera are also of someimportance. The arthropods in question are all cockroaches, and theyare probably of special importance as intermediate hosts for parasitesof such rodents as rats and mice. These rodents seem to eatcockroaches with dependal^le certainty, and the association of rats,mice and roaches in the household provides a suitable and, so to speak,natural combination of factors for the benefit of these spirurids. Onthe other hand, the development of spirurid parasites of sheep, cattleand horses in cockroaches inust be regarded as a case in which theroach merely serves as a host for a worm which cannot depend onsuch a host for its transmission, but which is capable of developingin that host as a case of accidental parasitism. In this connection itmay be noted that roaches will serve as intermediate hosts for so manyworms in this way that these insects make excellent experiment ani-mals for carrying out life-history experiments in the laboratory. Theplentiful supply of these insects in winter, a thing so unfortunatefrom some points of view, is a fortunate thing for the parasitologistwho obtains interesting worms in winter at a time when other insectsare scarce, and wishes to carry out feeding experiments on someinsect.The Diptera appear as intermediate hosts of spirurids with 14species serving as hosts for 3 known species of spirurids, all speciesof the genus Hahroneina and all parasitic in horses and other mem-bers of the Equidae. This association obviously depends in part on theimportance of the manure of horses and other Equidae as a breeding 46 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 81 place for Diptera. The transmission of the worm from the fly tothe horse appears to present several compHcations. It was surmised byRansom that horses might swallow flies which had fallen in drinkingtroughs or were benumbed in feed troughs on cold mornings. Sub-sequent work has indicated that the worms may escape from theproboscis of flies as they feed on the moist lips of horses, and pre-sumably these worms may get to the stomach and develop to adultworms. However, if the fly feeds on the conjunctiva of the eye thelarval worms may escape to the eye, remaining there as larvae andcausing a habronemic conjunctivitis. If the fly feeds on a wound, theworms may escape and remain in the wound as larvae, causing " sum-mer sores " or cutaneous habronemiasis. Finally, the worms may befound as larvae in the lungs, causing pulmonary habronemiasis, butthe precise method of infection here remains to be ascertained. Thesecases illustrate the fact that there are numerous deviations from thecut-and-dried rule that intermediate hosts either transmit worms bybeing eaten by the primary host, or else transmit the worms by bitingthe primary host.One member of the Siphonaptera occurs as a somewhat doubtfulhost of a rat spirurid, Protospiriira nmris, but the case for this shouldbe developed by feeding experiments.The one bird nematode of the family Spiruridae having a knownlife history is Hartcrtia galUnarum, and this worm utilizes a termiteas its intermediate host, the host here serving as food for chickenswhich devour them with great eagerness.THELAZIIDAEIn the Thelaziidae, we have a member of the Orthoptera, theroach Pycnoscelis surhiamensis, serving as the intermediate host ofthe chicken eyeworm, Oxyspirura mansoni, and also for the somewhatdubious species, O. parvovum, distinguished from O. rnavsoni only bythe smaller size of the egg. This life history was worked out byFielding in Australia and somewhat later, but independently, bySanders in Florida in the United States. At present the eyeworm,0. mansoni, appears to be confined in the United States to Florida,so far as our records show, but the intermediate host now has a muchwider range in this country and unless measures are taken to stampout the worm in Florida we can confidently expect it to spread beyondthe confines of that state. The movements of the infected primaryand secondary hosts by the swift methods of modern transportationover wide areas can hardly fail to ensure this result. [Since the abovewas written, the eyeworm has been found outside of Florida in thiscountry.] NO. 15 ARTHROPOD HOSTS OF HELMINTHS HALL 47ACUARIIDAEIn the A> uariidae, we are dealing with bird parasites. Of the twoworm species involved, one is a parasite of water birds, Anseriformes,and it is not surprising to find that this worm, Echimiria uncinata,uses Cladocera as its intermediate hosts, the one known intermediatehost being Daphnia pulex. The other worm is a parasite of landbirds, Galliformes and Columbi formes, and utilizes an isopod, Por-cellio laevis. [Cram has since found grasshoppers to be intermediatehosts for Acuariidae of terrestrial birds.]TETRAMERIDAEIn the Tetrameridae we are again dealing with bird parasites, andhere again the intermediate hosts are Entomostraca, a cladoceran,Daphnia pulex, and an amphipod, Gamnmrus pulex. The one wormfor which we know the life history, Tetrameres Ussispim, is usuallyand normally a parasite of water birds, Anseriformes, and its occur-rence in land birds must be regarded as following from the accidentalswallowing of the infected entomostracans while drinking, whereasin water birds we are dealing with a dependable arrangement, fromthe standpoint of the parasite, based on Entomostraca in the doublerole of food for the primary host and of secondary host for theworm. [Cram has recently found grasshoppers serving as inter-mediate host of tetramerids of terrestrial birds.]CUCULLANIDAEFor the one cucullanid with a known life history, a f^sh nematode,copepods and aquatic isopods serve as intermediate hosts, the hostsalso serving as food for fish.CAMALLANIDAEFor the two camallanids with known life histories, one a f^shnematode and one a turtle nematode, copepods are hosts for both anddragonflies also serve as hosts for one. These hosts are also food forthe primary hosts. HEDRURIDAEOf two species of hedrurids, parasitic in reptiles, amphibians andfish, one uses aquatic isopods and one amphipods as mtermediatehosts. . .The foregoing families are regarded by many parasitologists aspart of the superfamily Spiruroidea, and in this superfamily the lifehistory is usually one in which the transfer of the larval nematode tothe primary host is accomplished when this host swallows the sec-4 h;:^ 48 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 81 oiidary host, either as food or accidentally, such apparent exceptionsas in the case of Habronema being the unusual thing. We now takeup a group of worms which all fall in the family Filariidae, regardedby those who recognize the superfamily Spiruroidea as describedabove, as being part of the superfamily Filarioidea, the two super-families being grouped on their affinities as the Filariata.FILARIIDAEIn the Filariidae the customary mode of transmission of the wormis by the bite of the secondary host, this host becoming infected whenit bites an infested primary host and in turn infecting a primary hostby biting it after an interval in which the worm develops to the in-fective stage in the secondary host. It is to be expected, then, thatthe biting Diptera will show up prominently in this list of intermediatehosts, and we find a long list of such hosts recorded as transmittingnumerous species of filarid worms. Here we have a number of im-portant worm parasites of man and dogs, including such filarids asWuchereria hancrofti and Loa loa of man, and the heart worm,Dirofilaria immitis, a serious j^est of dogs in the hunting field.Mosquitoes take first place in this group of Diptera, many speciestransmitting W. hancrofti and D. immitis, while the tabanids, espe-cially Chrysops spp., function for Loa loa.The Siphonaptera, Mallophaga, Anopleura, and Arachnida are allcharged with the transmission of filarid worms.DRACUNCULIDAEIn the peculiar genus Dracunculus. including the guinea worm ofman, D. medinensis, the worms usually infest superficial body partsof the primary host, and when these come in contact with water, theworms release large numbers of embryos, some of which are swal-lowed by copepods. The larval worms develop in these hosts to theinfective stage and when these hosts are swallowed by suitable pri-mary hosts the worms develop to maturity.ARTHROPODS AS INTERMEDIATE HOSTS OFACANTHOCEPHALIDSThe acanthocephalids quite generally utilize at least one inter-mediate host, and sometimes two such hosts, the second one a fish,amphibian, or bird in some cases, in their life history. These firstintermediate hosts are sometimes snails or leeches, but in most of thereported cases the first intermediate host is an arthropod. The follow-ing list shows the reported hosts for the species having known lifehistories : NO. 15 ARTHROPOD HOSTS OF HELMINTHS HALL 49 Co t>) ^ fi" p S 3 ^b e « .=3 to2 s s « f^Q -O -C) —. - ^ -o -o^ '^ ^ ^ x: cq U•S • s s !? •« •- -st3au o o w;: -s s 5 '-s ^5 ^J o, o, O g •o '^ 2 ^.f^ S i e Q d "ot^ ^ D. '^ ,U Dh ^ D u j: 2 2 R -^ •C' rap S c ^ ^1^CO Co to U_ U 1^ G^ >' s ^ s ^ -^ "^ aS ^ 2 ^ .b S "^ "^ -s fi ^ 2 -3 « "$ o o § Se « o s s « s-Cli Gi CQ cq CQ ^ t-i i; (^ ~ 2 ^ « "o O -Ci. -t. •H e ^ HCi U ^ W l-U NO. 15 ARTHROPOD HOSTS OF HELMINTHS HALL 53An inspection of the tables indicates, first of all, that we have butlimited knowledge of the life histories of acanthocephalids in any-one family, and that it will not be possible to generalize to any greatextent on such limited data. What may be said is as follows : NEOECHINORHYNCHIDAEIn the Neoechinorhynchidae we know the life history of oneacanthocephalid, a parasite occurring in a large number of fish andin some reptiles and amphibians, and the known intermediate hostsare species of Siulis, one an unrecognized species, in the Neuroptera,other hosts being leeches and snails.GIGANTORHYNCHIDAEIn the Gigantorhynchidae we again have only one known lifehistory. In this case the echinorhynch occurs as an adult in mammalsof various groups, including primates, carnivores, and insectivores,and has a species of Blaps, a coleopteron, as an intermediate host.OLIGACANTHORHYNCHIDAEIn the Oligacanthorhynchidae we again have one acanthocephalidwith a known life history, the well-known thorn-headed worm ofswine, occurring in such animals as swine, carnivores, and man andother primates. This worm has a number of species of scarabaeidbeetles as its intermediate hosts.CORYNOSOMIDAEIn the Corynosomidae we have one know^n life history, that of anacanthocephalid of water fowl, Anseriformes, using crustaceans,amphipods and crayfish, as intermediate hosts.MONILIFORMIDAEIn the Moniliformidae we have a parasite with a wide range ofprimary hosts, from man, carnivores and rodents to rapacious birds,and having as its intermediate hosts two si>ecies of Coleoi)tcra and twoof Orthoptera. ECHINORHYNCHIDAEIn the Echinorhynchidae we have three acanthocephalids parasiticin fish of numerous species, two of them with an amphipod as anintermediate host and one with an aquatic isopod as an intermediatehost; and one acanthocephalid parasitic in various amphibians andwith an amphipod as its intermediate host. 54 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8lBy way of summary it may be noted that of three acanthocephalidsparasitic in mammals, all develop in insects, all with Coleoptera andone with Orthoptera also as intermediate hosts ; the one acanthocepha-lid habitually parasitic in water birds uses crustaceans as intermediatehosts ; and that of five acanthocephalids parasitic in fish and amphib-ians, four use crustaceans as intermediate hosts, these being amphi-pods in two cases, isopods in one case, and both amphipods and isopodsin one case. In the case of one acanthocephalid in fish, the Neurop-tera serve as hosts. Insects are apparently of major importance foracanthocephalids of mammals and crustaceans for acanthocephalids offish.In the foregoing lists of parasites arranged by orders and families,the names given for the arthropod hosts are those under which theyare reported in the literature and no attempt is made in these lists toeliminate synonyms for the reason already given that it is easier totrace these references in the literature under the names quoted. Inthe following lists arranged on the basis of intermediate hosts, syn-onyms are cross-referenced to the names accepted by the authoritiesalready mentioned in the first part of the paper.ARTHROPOD HOSTS OF HELMINTHS, ARRANGED BY HOSTGROUPSINSECTAANOPLEITRAHaematopinus pilifenis. See Linog-nathiis piliferus.Lhiognathus piliferusDipetalonema recondittimDERMAPTERAAnisolabis annulipesHymenolepis diminutaHymenolcpis microstomaEPHEMERIDABlasturus acpidus. See LeptopJilebiacupida.CIaeon dlpterum? Opisthioglyphe endolobaEphemera danicaStephanophiala farionisEphemera vulgataAllocreadiuni isoporumOpisthioglyphe endolobaSpiroptera ephemeridarum EphemeridLecithodendrimn lagenaCercaria secimdaHexagenia sp.Crcpidostomum cornutumStephanophiala farionisLeptophlebia cupidaAllocreadiuni communeOllgoneuria rhenanaSpiroptera ephemeridarumCOLEOPTERAAblattaria laevigataWeinlandia uncinataAkis goryiSpirura gastrophilaSpirocerca sanguinolentaAkis spinosaHymenolepis diminutaAphodius castaneus. See Aphodiusrufus castaneus.Aphodius coloradensisGongylonema scutatum NO. 15 ARTHROPOD HOSTS OF HELMINTHS HALL 55Aphodius distinctusGongylonema sciitatumAphodius fenioralisGongylonema scutatumAphodius fimetariiisProtospirura gracilisGongylonema sciilatumLarval ncma of Cobb, 1922Aphodius granariusHymcnolepis cariocaGongylonema scutatumAphodius haetnorrh oidalis? Gongylonema pulchrumAphodius ohscuriis? Cittotacnia marinotacAphodius rubcolusGongylonema scutatumAphodius rujiisArducnna strongylinaAphodius rufus castaneusArduenna strongylinaAphodius sp.Gongylonema sciitatumAphodius vittatusGongylonema scutatumAteuchus sacer. See Scarabaeus sacer.Ateuchus sp.Physaloptera abbreviataBlaps appendiculataGongylonema scutatumBlaps emondiGongylonema scutatumBlaps gigasMoniliformis moniliformisBlaps mortisagaAgantonematodum blapis-mortisagaeBlaps mucronataMoniliformis moniliformisBlaps spp.Spirura gastrophilaGongylonema scutatumGongylonema brevispiculumGigantorhynclius spirtdaBlaps strauchiSpirura gastrophilaGongylonema scutatumGongylonema brevispiculumCaccobius schrebcri? Gongylonema piilchrum Canthon sp.Spirocerca sanguinolentaCetonia aurafaSpirura talpaeMacracanthorhynchns hirudinaceusChironitis irroratusGongylonema mucronatumCopris hispanusSpirocerca sanguinolentaDiloboderus abderusMacracanthorhynchns hirudinaceusGeotrupes doiiei. See Geotrupes {Ste-reopyge) douei.Geotrupes (Stereopyge) doueiSpirocerca sanguinolentaf Physocephalus se.valaiusGongylonema mucronatumGeotrupes (Anoplolrupes) stercorosusChoanotaenia infundibulumHymenolepis serpentulnsf Physocephalus sexalatusGeotrupes stercorariusPhysalocephalus sexalatusGeotrupes stercorosus. See Geotrupes(Anoplotrupes) stercorosus.Geotrupes sylvaticusChoanotaenia infundibulumHymenolepis serpentulnsGymnopleurus mopsusGongylonema mucronatumGymnopleurus sturmiSpirocerca sanguinolentaGongylonema mucronatumIlybius fuliginosusHaplometra cylindraceaIlybius sp.Cercaria primaMelolontha melolonthaMacracanthorhynchns hirudinaceusMelolontha vulgaris. See Melolonthamelolontha.Onticellus fulvusGongylonema scutatumOnitis irroratus. See Chironitis irro-ratus.Onthophagus bedeliPhysocephalus sexalatusGongylonema mucronatum 56 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8lOnthophagus hecateArduenna strongylinaPhysocephalus sexalatusGongylonema sciitatumOnthophagus nebulosusPhysocephalus sexalatusOnthophagus pennsylvanicnsGongylonema scutatumOnthophagus sp.Spirura gastrophilaOnthophagus taunts? Gongylonema scutatumPhyllophaga arcuataMacracanthorhynchus hirudinaceusPhyllophaga fervens. See Phyllophagafusca.Phyllopliaga fuscaMacracanthorhynch us h irudinaccusPhyllopliaga rugosaMacracanthorhynchus hirudinaceusPliyllophaga vehcmensMacracanthorhynchus hirudi)iaceusPinotus carolinusLarval nema of Cram, 1924Scarabaeus sacerSpirura gastrophilaSpirocerca sanguinolentaPhysocephalus sexalatusGongylonema mucronatumScarabaeus variolosusSpirocerca sanguinolentaPhysocephalus sexalatusScaiirus stria tusHymenolepis diminutaSilpha laevigata. See Ablattaria lae-vigata.Strategus jiilianusMacracanthorhynchus hirudinaceusTenebrio molitorHymenolepis arzncolaef Hymenolepis nanaHymenolepis diminutaHymenolepis microstomaOnchoscolex decipiensProtospirura mnrisGongylonema neoplasticumTenebrio obscurusGongylonema sp.Tribolium ferrugineumHymenolepis diminuta " Water beetles "Pleurogenes mediansPleurogenes clavigerPleurogenes confususXyloryctes satyrusMacracanthorhynchns hirudinaceus Aedes aegyptiFilaria ozsardiWuchereria bancroftiDirofilaria immitisDirofilaria repensDipetalonema perstansAedes albolineataWuchereria bancroftiAedes albopictusWuchereria bancroftiAedes casplusDirofilaria immitisAedes fasciatus. See Aedes aegypti.Aedes {Finlaya) togoiWuchereria bancroftiAedes gracilis. See BironcUa gracilisand Anopheles gracilis.Aedes perplexusWuchereria bancroftiAedes pseudoscutcllaris. See Aedesvariegatus.Aedes punctatus. See Aedes casf^ius.Aedes scutellaris. See Aedes albopic-tus.Aedes sugens. See Aedes vittatus.Aedes vagansDirofilaria immitisAedes variegatusWuchereria bancroftiAedes vexansDirofilaria immitisAedes vigilaxWuchereria bancroftiAedes vittatusDipetalonema perstansAnastellorhina augurHabronema sp.Anopheles albimanusFilaria ozzardiWuchereria bancroftiAnopheles albitarsisFilaria ozsardi NO. 15 ARTHROPOD HOSTS OF HELMINTHS HALL 57Anopheles algeriensisDirofilaria inunitisAnopheles annulipesWuchereria bancroftiAnopheles argyritarsisWuchereria bancroftiAnopheles barbirostrisWuchereria bancroftiAnopheles bifnrcatusDirofilaria immitisAgamodistonium martiranoiAnopheles claviger. See Anophelesbifurcatus.Anopheles costalis. See Anophelesganibiae.Anopheles cnlifacicnsAgamodistonium sintoniAnopheles fuliginosnsCercaria of Stephens & Christophers,1902Anopheles funestus listoni. See Ano-pheles listonii.Anopheles gambiaeWuchereria bancroftiDipetalonema pcrstansAnopheles gracilisf Wuchereria bancroftiAnopheles hyrcanus pseudopictusDirofilaria immitisAnopheles hyrcanus sinensisWuchereria bancroftiDirofilaria immitisAnopheles listoniiAgamodistomum sintoniAnopheles macuUpennisLecithodettdrium lagenaAgamodistomum anophelisFilaria oszardiFilaria sp. Fuelleborn, 1909Dirofilaria immitisDirofilaria repensDipetalonema perstansAnopheles palestinus. See Anophelessuperpictus.Anopheles rossi. See Anopheles snb-pictus.Anopheles sinensis. See Anopheleshyrcanus sinensis.Anopheles sinensis peditaeniatusWuchereria bancrofti Anopheles sinensis pseudopictusDirofilaria immitisAnopheles sinensis vanus. See Ano-pheles barbirostris.Anopheles subpictusCercaria of Soparkar, 1918Cercaria of Stephens & Christophers,1902Wuchereria bancroftiAnopheles superpictusWuchereria bancroftiDirofilaria immitisAnopheles tarsimactdatusFdaria ozsardiBironella gracilisf Wuchereria bancroftiChironomus libiferusLissorchis fairportiChironomus plumosusLecithodendrium lagenaChrysoconops fuscopennatus. SeeMansonia fuscopennatus.Chrysops centurionisLoa loa? Dipetalonema perstansChrysops dimidiatusLoa loaChrysops longicornisLoa loaChrysops sdaceusFilaria sp. of Med. Rept., Lagos,Nigeria, 1918Loa loaCorethra sp.Cercaria primaCercaria secundaCule.r ciliaris. (May be Aedes cin-ereus, fide Dyar.)Wuchereria bancroftiCulex fatigans. See Cidex quinque-fasciatus.Culex ftiscocephalusWuchereria bancroftiCulex gelidusWuchereria bancroftiCulex hortensisCercaria of Joj'eux, 19 18Culex malariae. See Aedes vexans.Culex microannulatus. See Culex siti- 58 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 8lCulex peniciUaris. See Aedes caspius.Ciilex pipiensWuchereria bancroftiDirofilaria immitisDipetaloncma perstansCulex procax. See Aedes vigilax.Culex qu'mqiicfasciatiisFilaria ozzardiWuchereria bancroftiDirofilaria immitisDipetaloncma rcconditumCulex sitiensWuchereria bancroftiCulex sp.f Onchocerca caccnticnsCnlcx teniatus. See Aedes aegypti.Culex vigilax. See Aedes vigilax.Cnlicoides austeniDipetaloncma perstansCulicoides grahamiDipetalotiema perstansEusimulium reptans 'Cystopsis acipenserisFcmnia sp.Larval nema of Johnston & Ban-croft, 1920Haematopota cordigcraLoa loaHippocentrum triinacidatiimLoa loaHoiuardina albolincata. See Aedes al-bolineata.Lyperosia exiguaHabronema microstomaMansonia africanaWuchereria bancroftiMansonia anniilipesWuchereria bancroftiMansonia fuscopennatusDipetaloncma perstansMansonia pseudotitillansWuchereria bancroftiMansonia sp.Dipetaloncma perstansMansonia uniformisFilaria sp. Castellani & Chalmers,1913Wuchereria bancroftiDipetaloncma perstans Mansonioidcs anmdipes. See Mansoniaannulipes.Mansonioidcs pseudotitillans. See Man-sonia pseudotitillans.Mansonioidcs uniformis. See Man-sonia uniformis.Musca bczsiHabronema spp.Musca domcsticaChoanotacn ia infimdib u In m Davainea tetragonaDavainea cesticillusHabronema microstomaHabronema megastomaHabronema muscaeMusca fergusoniHabronema megastomaHabronema muscaeMusca hum HisHabronema megastomaHabronema muscaeMusca lusoriaHabronema megastomaHabronema muscaeMusca terrae-reginaeHabronema megastomatiabronema muscaeAgamospirura muscaruinMusca vcntrosaHabronema mc'gastomaHabronema muscaeMusca vetustissimaHabronema megastomaHabronema muscaeMysomyia superpicta. See Anophelessuperpictus.Mysorhynchus pseudopictus. See Ano-pheles hyrcanus pseudopictus.Panoplites africanus. See Mansoniaafricanus.Panoplites sp.Dipetaloncma perstansPseudopyrellia sp.Habronema megastomaHabronema muscaeSarcophaga melanuraHabronema microstomaSarcophaga miseraHabronema muscae NO. 15 ARTHROPOD HOSTS OF HKI.MINTHS HALL 59Scufowyia albolincafa. See Acdes albo-lineata.SimulidsOncocerca caecutiensSitnulium damnosumOncocerca volvidusStegomyia fasciata. See Acdes acgypti.Stomoxys calcitransHymenolepis cariocaHabronema microstoma? Habronema mtiscaef Setaria lahiato-papillosaTabanus circiimdatitsAgamofilaria tabanicolaTaeniorhynchus annidipcs. Sec Man-sonia annuUpes.Taeniorhynchus domesticus. ProbablyCulex pipiens, q. v.Wuchereria bancroffiTanypus decoloratusLissorchis fairporti Hodotermes pretoriensis. See Macro-hodotermes mossambicus trans-vaalensis.Macrohodotermes mossambicus trans-vaalensisHartcrtia gallinarum LEPIDOPTERAAylossa dimidiataHymenolepis diminutaAphornia gularisHymenolepis diminutaAsopia farinalisHymenolepis diminutaNymphiila nymphacataFlukeParalipsa gidaris. See Aphorniagularis.Pyralis farinalis. See Asopia farinalis.Tinea granellaHymenolepis diminuta MALLOPHAGA " Bird louse "? Filaria cypseliTrichodectes latusDipylidium caninumNEUROPTERAMystacides nigraDistomum mystacidisSialis lutaria. See Sialis flavilatcra.Sialis flavilateraDistomum notidobiaeDistomum sialidisNeoechinorhynchus ru t HiSialis nigerNeoechinorhynchus rutiliODONATAAeschna sp.Prosotocus confususAgrion puella. See Coenagrion puella.Agrion spp.Gorgodera pagenstecheriGorgodera varsoviensisPleurogenes mediansDistomum sp. of VillotProcercoid of Galli-Valerio, 1923Camallaniis lacustrisAgrion virgoPneumonoeces variegatusPneumonoeces sintiligenusHalipegus ovocaudatusCalopteryx virgo. See Agrion virgo.Coenagrion puellaTatria acanthorhyncha.Cordulia sp.Prosotocus confusus " Dragonfly "Plagiorchis ameiurcnsisCercaria primaEpitheca sp.Gorgodera pagenstecheriGorgodera varsoviensisGorgodera cygnoidesLibcllula quadrimaculataProsthogonimus intercalandusProsthogonimus pellucidusTetragoneuria sp.Prosthogonimus sp. of Kotlan andChandler 6o SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l PLECOPTERAPcrla IncaudataOpisthioglyphc cndolohum " Perlid larva "Plagiorchis ntacidosusLecithodoidrium lagcna ORTHOPTERAB Iatla or ic It talisSplnira ijastroph ilaf Sp'irocerca sanyxnnolcntaGongyloneina ncoplasticiimGongyloncma sp.Moniliformis moiiiliforniisBlattclla gcrmanicaProtospirnra columbianaGongyloncma ncoplasticumGongyloncma scuta turnGongyloncma fulchrumPeriplaneta amcricanaGongyloncma ncoplasticumGongyloncma oricntalcGongyloncma sp.Moniliformis moniliformisPeriplaneta australasiacGongyloncma orientatePycnoscehts surinamcnsisOxyspirura mansoniOxyspirnra parvovnni SIPHONAPTERACeratophyllus fasciatusHymcnolcpis dimimita? Hymenolepis nanaHymenolepis microstomaAgamonema sp. Johnston, 19 13Ctenocephalus canisDipylidiiim can inii m Hymenolepis diminutaDirofilaria immitisDipetaloncma rcconditiimCtenocephalus fclisDipylidiiim caninumDirofilaria immitisDipetaloncma reconditumLcptopsylla musculiHymenolepis diminuta Mcsopsylla cuctaCysticercoid of Dampf, 1910Pulex irritansDipylidiiim caninumHymenolcp is diminutaDipetaloncma reconditumDipetaloncma pcrstansXcnopsylla chcopisHymenolepis diminuta? Hymenolepis nana? Protospirnra murisAgamonema sp. Johnston, 1913 TRICHOPTERAAnabolia nervosaAllocreadium isoporumOpisthioglyphc endolobumChaetopteryx villosaAllocreadium isoporumDrusus trifidusPlagiorchis maculosusLimnophilus AavicornisOpistliioglyplic endolobumLimnophilus griseusOpisthioglyphc endolobumLimnophilus lunatusOpisthioglyphe endolobumL ininoph ilus rhombicusOpisthioglyphc endolobumDisfomum limnophiliNotidobia ciliarisDistomum notidobiaePhryganea grandisOpisthioglyphc endolobumLecithodendrium chcilostomumBrachycoelium retusumDistomum pJiryganeaePhryganea sp.Lecithodendrium die dost mumRhyacophila nubilaFluke UNPLACED "Amphibious insects "Plagioporus sp.Eumegacetes sp. " Raubinsekten "Gorgodera vitelliloba NO. 15 ARTHROPOD HOSTS OF HELMINTHS HALL 61ARACHNIDAACARINAArgas sp.Dipctaloncnia PersiansIxodes ricinus? Filaria niartisOntithodorus moubataDipetaloncina Persians Rhipicephalus sanguineusDipetalonema reconditumDipetalonema grassiiDirofilaria immitisRhipicephalus sicidus? Dipetalonema recondihim " Tick "/ Filaria viitchelli Fontaria virginicnsisHynienolepis diniinutaGlomeris limbataCestode larva MVRIAPODAJulus guthdatusNematode larvaJulus sp.Hynienolepis diniinutaCRUSTACEAAMPHIPODAAllorchestes sp.? Hedruris orestiaeGammarus loctistaDistonium gammari RentschPolymorphus hoschadisGammarus ornatus. See Gammaruslocusta.Gammarus pulexOpisthioglyphe endolobumDistonium agamosDistomum gammari LinstowDistonium pidicisHynienolepis collarisHynienolepis tcnuirostrisAploparaksis dujardiniEchinocotyle mrazekiCysticercoides sp. Mrazek, 1896Cysticercus bifurcusCysticercus hamanniCysticercus taeniae-pachyacanthaeCysticercus sp. Luehe, 19 10Cysticercus sp. Mrazek, 1890Taenia sp. Daday, 1900; 168Tetrameres fissisptnaPolymorphus boschadisPomphorhynchus laevisHyallela astecaEchinorhynchus thecatusProteocephalus ambloplitis Hyallela knickerbockeri. See Hyallelaasteca.Pontoporeia hoyiEchinorhynchus ranaeThemisto libellulaSinistroporus simplexBRANCHIOPODAApus sp.Agamodistoniuni apodisCLADOCERABythotrephcs longinianusProteocephalus agonisDaphnia pulexEchinuria uncinataTetrameres fissispinaLeptodora kindtitProteocephalus agonis Acartia clausaHemiurus appcndiculatusAcartia sp.Derogenes variusBoeckella brasiliensis. See Pseudo-boeckella brasiliensis.Cyclops agilis. See Cyclops serrulatiis.Cyclops albidusProteocephalus ambloplitis 62 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l Cyclops bicuspidatusHymenolepis tenuirostrisDrepanidotaenia lanceolataSchistocephahis solidnsBothriocephalus cuspidatusCorallobothrium fimbriatumDracunculus globocephaJusCyclops brevicaudata. See Cyclopsstrenuus.Cyclops brevispinosiisBothriocephalus cuspidatusDiphyllobothrium latumCyclops coronatus. See Cyclops fuscus.Cyclops crassicornisHymenolepis brachycephaJaCyclops fimbriatus. See Plaiycyclopsfimbriatus.Cyclops fuscusDracunculus medinensisCyclops leuckartiProteocephalus ambloplitisBothriocephalus cuspidatusDiphyllobothrium mansoniDracuncitlus medinensisCyclops lucidulusHymenolepis collarisCyclops oithonoides. See Mesocyclopsoithonoides.Cyclops prasinusProteocephalus ambloplitisCorallobothrium giganteumBothriocephalus cuspidatusDracuncidus medinensisCyclops pulchellus. See Cyclops bicus-pidatus.Cyclops quadricornisCucullanus elcgansDracunculus medinensisCyclops robustusDiphyllobothrium latum.Cyclops serratus. See Cyclops bicus-pidatus.Cyclops serrulatusHymenolepis collarisHymenolepis tenuirostrisHymenolepis fasciculataHymenolepis microsomaProteocephalus toridosus ' Proteocephalus longicollisProte-ocephahis percae Corallobothrium giganteumCorallobothrium fimbriatumBothriocephalus cuspidatusSchistocephalus solidusA bothrium infundibuliformisAbothrium crassumCysticercoid of Rossiter, 1893Cysticercus quadricurvatusCysticercus gruberiCysticercus sp. Luehe, 1910Cyclops sp.Fimbriaria fasciolarisCamallanus lacustrisCamallanus microcephalusDracunculus sp.Philometra sanguineumCyclops strenuusProteocephalus torulosusProteocephalus longicollisProteocephalus fercaeIchthyotaenia sp. Fuhrmann, 1926Hymenolepis setigeraDiphyllobothrium latumAbothrium crassumAbothrium infundibuliformisTriaenophorus nodidosusCysticercus gruberiDracuncidus medinensisCyclops tenuicornis. Probably Cyclopsalbidus q. v.Distomum sp. HerrickCyclops varius. See Cyclops serrula-tus.Cyclops vernalisHymenolepis anatinaHymenolepis collarisCyclops viridisHymenolepis collarisHymenolepis gracilisHymenolepis fasciculatusDracunculus medinensisDiaptomus africanusPlerocercus africanusDiaptomus alluaudiHymenolepis anatinaDicranotaenia dubiaDiaptomus asiaticusEchinocotyle linstozviEchinocotyle polyacanthaTaenia sichyi NO. 15 ARTHROPOD HOSTS OF HELMINTHS HALL 63Diaptomus castorProteocephalus tondosusDiaptomus coerulensHymenolepis collarisHymenolepis gracilisHymenolepis tenuirostrisHymenolepis fasciculatusHymenolepis setigeraDiaptomus gracilisDiphyllobothrium latumDiaptomus graciloidesDiphyllobothrium latumDiaptomus oregonensisDiphyllobothrium latumDiaptomus sp.Cysticercoides sp. Mrazek, 1898Cercocystis dendrocercusPhilometra sanguineumDiaptomus spinosusHymenolepis anatinaHymenolepis gracilisDrepanidotaenia lanceolataEchinocotyle linstowiDiaptomus vulgarisFimbriaria fasciolarisLeptocyclops agilis. See Cyclops scr-rulatus.Mesocyclops oithonoidesProteocephalus percaePlatycyclops fimbriatusHymenolepis brachycephalaTriaenophorus nodulosusPseudoboeckella brasiliensisEchinocotyle mrasekiOSTRACODACandona CandidaHymenolepis corontdaCandona neglecta tubercidataHymenolepis gracilisCandona rostrataHymenolepis gracilisCyclocypris globosaHymenolepis gracilisHymenolepis coronulaHymenolepis liophallosHymenolepis venustaEchinocotyle rosseteriCysticercoides sp. Rossiter, 1890 Cyclocypris laevisHymenolepis coronulaCyclocypris ovumHymenolepis corontdaCypria ophthalmicaHymenolepis anatina.Hymenolepis gracilisHymenolepis coronulaEchinocotyle rosseteri " Cypris agilis "Hymenolepis venustaCypris cinerea. See Cyclocypris glo-bosa.Cypris compressa. See Cypria ophthal-mica.Cypris elongataTaenia sp. Daday, 1900Cypris incongruens. See Hcterocyprisincongruens.Cypris ophthalmica. See Cypria oph-thalmicaCypris ovata. See Cypris pubera.Cypris ovum. See Cyclocypris ovum.Cypris puberaHymenolepis anatina.Cypris virens. See Eucypris virens.Cypris viriens. .See Eucypris virens.Dolcrocypris fasciataHymenolepis gracilisEucandona hungaricaHymenolepis anatinaEucypris crassa^Hymenolepis anatinaEucypris virensHymenolepis collarisHymenolepis coronulaHymenolepis gracilisHeterocypris incongruensHymenolepis anatina " Ostracod "Cysticercus sp. Luehe, 1910 DECAPODAAstacus astacusAstacotrema cirrigerumHymenolepis collarisHymenolepis tenuirostrisPolymorphus boschadis 64 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l Astacus fluviatilis. See Astacus asia-cus.Astacus japonicits. Sec Camharo'idcsjapo)iicits.Astacus IcptodactylusDistoiiitun rcinhardiCambaro'idcs japoniciisParagonimus icestcnuaii i Cambaro'idcs siin His? Paragonimus ivcslcrmaniCambanis propinqmisMicrophallus opacusCambanis spp.Crcpidosto ni u ui corn utuniCcrataspis nionstrosaDinurus tornafus " Crabs "Distonuim kalapdi " Crayfish "Astacntrcma cirrigcruniAcrolichaniis petalosaPlagiorchis ameiurensisDistoma of Cooper, 1883Distomum of Linton, 1892Eriocheir japonicusParagonimus ivestcrnianiStcphanolecithus parzmsGcothclphusa dchaani. See Pofamon{Gcothelphusa) dchaani.Gcothclphusa obtusipes. See Potamon{Gcothelphusa) obtusipes. " Marine decapods "Rhynchobothrius ruficollis Potamobiiis astacus. See Astacus asta-cus.ParathclpJuisa (Parafhclphusa) sinen-sisStcphcuiolccith us parvusPotamon dchaanii. See Potamon( Gcothclphusa) dchaani.Potamon' obtusipes. Sec Potamon(Gcotliclphusa) obtusipes.Potamon sinensis. See Parathclphusa(Parathelphusa) sinensis.Potamon (Gcothclphusa) dehaaniParagonimus zvestcrmaniMacroorchis sp in ulosusStephanolecithus parvusPotamon (Gcothclphusa) obtusipesParagonimus ivestermaniStephanolecithus parvusPseudotheJphusa iturbciParagonimus ivestermaniScsarma dchaaniiParagonimus ivestermaniStephanolecithus parvus Ascllus aquaticusCaniallanus elcgansHedruris androphoraAcanthocephahts luciiEchinorhynchus ranaePorcellio laevisDispharynx spiralisGENERAL DISCUSSIONOn the basis of the foregoing lists, the arthropod hosts are arrangedbelow in their approximate order of relative importance for eachorder of parasites, with a resume of the numbers of host and para-site species involved.As intermediate hosts for tapeworms with primary hosts living inwater or feeding on arthropods which live in water, the Copepoda areof outstanding importance, the next most important group being theOstracoda. The Amphipoda, Decapoda, and Cladocera are much lessextensively involved as intermediate hosts for tapeworms so far asis known at the present time. NO. 15 ARTHROPOD HOSTS OF HELMINTHS HALL Cestoda No. of hostIntermediate spp.host group involvedCrustacea:Copepoda 27Ostracoda 15Amphipoda iDecapoda 2Cladocera 2Insecta :Coleoptera 8Siphonaptera 7Diptera 2Lepidoptera 4Odonata 2Dermaptera iMallophaga iMVRIAPODA . . .'. 2 No. of parasite spp.with known hostsfor adults29653I944II2II No. of parasitespp. reported aslarvae withoutknown hostsfor adults As intermediate hosts for tapeworms of land animals, the Coleop-tera are distinctly the most important group, other insect groups beingof much less importance so far as we know. Trematoda No. of parasitespp. reported asNo. of host No. of parasite spp. larvae withoutIntermediate spp. with known hosts known hostshost group involved for adults for adultsCrustacea :Decapoda IS 8 4Amphipoda 3 i 4Copepoda 3 2 iBranchiopoda i o iInsecta:Diptera 11 2 8Trichoptera 11 2 4Odonata 8 6 2Ephemerida 5 5 ^Coleoptera 3 3 ^Unplaced insects 2 4. oNeuroptera; 2 o 3Plecoptera 2 iLepidoptera i o iAmong the Crustacea, the Decapoda are of outstanding importanceas hosts for flukes, some of these flukes occurring in land mammalswhich eat raw crabs or crayfish. 66 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8lAmong the Insecta, the apparent importance of the Diptera andTrichoptera is not well established. These groups rate high in numberof species serving as hosts, but as the flukes reported from them aremostly larval forms of which the adults are not known and whichmay later prove to represent no more known species than are alreadyknown and recorded here from these hosts, or only a few more, thesegroups cannot be rated at the present time as any more important thanthe Odonata or Ephemerida as hosts for flukes. Nematoda No. of hostInteimcdiate spp.host group involvedCrustacea :Copepoda 8Amphipoda 2Isopoda 2Cladocera iInsecta : *>Diptera 67Coleoptera 39Orthoptera 5Siphonaptera 5Ephemerida 2Anopleura iIsoptera iMallophaga iOdonata iArachnida 6 No. of parasite spp.with known hostsfor adults 722I 171054 II II6 No. of parasitespp. reported aslarvae withoutknown hostsfor adults Among the Crustacea, the Copepoda are the important group ascarriers of parasitic nematodes. Among the Insecta the Diptera are ofstriking importance, no less than 6"^ of the Diptera being reported ascarriers for a total of 17 nematode species, this fact being the resultlargely of the role of the mosquitoes as carriers of filarids. TheColeoptera take first rank as carriers of spirurids. Of lesser impor-tance are the Orthoptera and Siphonaptera, and the other groups ofinsects show but few host species and these accused of carrying butone nematode parasite. The Arachnida as a whole have been accusedof carrying 6 nematodes, and but 6 arachnids are incriminated. Thearachnids have not been reported as carriers of any parasitic wormsother than nematodes. NO. 15 ARTHROPOD HOSTS OF HELMINTHS—HALL 67Acanthocephala No. of hostIntermediate spp.host group involvedCrustacea :Amphipoda 4Isopoda IDecapoda iInsecta:Coleoptera 11Neuroptera 2Orthoptera 2 No. of parasite spp.with known hostsfor adults No. of parasitespp. reported aslarvae withoutknown hostsfor adults Among the Crustacea, the Amphipoda are of special significance ashosts for acanthocephalids of aquatic animals, so far as the life his-tories of such worms are known. The only other crustaceans involvedare Isopoda and Decapoda.Among the Insecta, the Coleoptera are of major importance ascarriers of acanthocephalids with known life histories. The only otherinsects involved are Neuroptera and Orthoptera.If we take the outstanding groups of intermediate hosts for eachorder of parasites, we have the following:For Cestoda : Copepoda and Ostracoda ; Coleoptera.For Trematoda : Decapoda ; Diptera, Trichoptera, Odonata, and Ephemerida.For Nematoda : Copepoda ; Diptera and Coleoptera.For Acanthocephala : Amphipoda ; Coleoptera.Among the insects, the importance of the Coleoptera is indicatedby the fact that this group is of decided significance for Cestoda,Nematoda, and Acanthocephala. The Diptera are important as car-riers of Trematoda and Nematoda. The Trichoptera, Odonata, andEphemerida only figure as outstandingly important for Trematoda.Among the crustaceans, the Copepoda are the major group as hostsfor both Cestoda and Nematoda. The Ostracoda are only known tobe important as hosts for Cestoda, the Decapoda as hosts for Trema-toda, and the Amphipoda as hosts for Acanthocephala.The following table is inserted to give a rapid check on the knownoccurrence in the dififerent arthropod hosts of parasites of the groupsinvolved in this paper. If an arthropod group is known to containintermediate hosts for the worm groups involved, an X is placed underthe worm group and opposite the host group. If there are no suchhosts known, an O is placed in the corresponding position. 68 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8lLIST SHOWING RECORDS (X) OR LACK OF RECORDS (O) OFPARASITE GROUPS IN HOST GROUPSArthropod group Cestoda Trematoda Nematoda AcanthocephalaAmphipoda X X X XBranchiopoda O X O OCladocera X O X OCopepoda X X X ODecapoda X X O XIsopoda O O X XOstracoda X O O OAnopleura O O X OColeoptera X X X XDermaptera X O O ODiptera X X X OEphemerida O X X OIsoptera O O X OLepidoptera X X O OMallophaga X O X ONeuroptera O X O XOdonata X X X OOrthoptera O O X XPlecoptera O X O OSiphonaptera X O X OTrichoptera O X O OInsecta ; unplaced O X O OMyriapoda X O O OArachnida O O X O It is of interest to note that of the 24 arthropod groups Hsted above,the number of groups used as hosts by cestodes, trematodes, and nema-todes is the same or almost the same, namely, 13 by cestodes andtrematodes and 14 by nematodes ; only 6 are used by acanthocephalids.From the foregoing something may be indicated as to the range ofparasites on the part of the various intermediate host groups, as fol-lows:Hosts for 4 worm groups : Amphipoda and Coleoptera.Hosts for Cestoda, Trematoda and Nematoda : Copepoda ; Diptera and Odonata.Hosts for Cestoda, Trematoda and Acanthocephala: Decapoda.Hosts for Cestoda and Trematoda : Lepidoptera.Hosts for Cestoda and Nematoda : Cladocera ; Mallophaga and Siphonaptera.Hosts for Trematoda and Nematoda : Ephemerida.Hosts for Trematoda and Acanthocephala : Neuroptera.Hosts for Nematoda and Acanthocephala : Isopoda ; Orthoptera.Hosts for Cestoda only : Ostracoda ; Dermaptera ; Myriapoda.Hosts for Trematoda only : Branchiopoda ; Plecoptera, Trichoptera, and un-placed insects.Hosts for Nematoda only: Anopleura and Isoptera; Arachnida.No group is yet reported as a host group for Acanthocephala only. NO, 15 ARTHROPOD HOSTS OF HELMINTHS HALL 69Taking the major host groups, the Crustacea, Insecta, Myriapoda,and Arachnida, as a whole and the four worm groups as a whole, wemay make the following summary : There are 48 species in the Cestoda which have arthropods asintermediate hosts and for which we know the primary hosts; thereare 22 larval forms in addition for which the primary hosts are notknown.There are 37 species in the Trematoda which have arthropods asintermediate hosts and for which we know the primary hosts ; there are2^ larval forms in addition for which the primary hosts are not known.There are 49 species in the Nematoda which have arthropods asintermediate hosts and for which we know the primary hosts ; thereare 12 larval forms in addition for which the primary hosts are un-known.There are 9 species in the Acanthocephala which have arthropodsas intermediate hosts and for which we know the primary hosts.There are altogether 143 species of worms parasitic in vertebrateswhich have arthropods as intermediate hosts and for which the pri-mary hosts are known ; there are 61 larval forms in addition for whichthe primary host is unknown.In the Crustacea there are 49 species which serve as intermediatehosts for Cestoda, 22 for Trematoda, 12 for Nematoda, and none forAcanthocephala.In the Insecta there are 25 species which serve as intermediatehosts for Cestoda, 46 for Trematoda, 122 for Nematoda, and 15 forAcanthocephala.In the Myriapoda there are 2 species which serve as intermediatehosts for Cestoda, and none for Trematoda, Nematoda, or Acantho-cephala so far as we know at present.In the Arachnida there are 6 species which serve as intermediatehosts for Nematoda, and none for Cestoda, Trematoda, or Acantho-cephala so far as we know at present.The Insecta are far in the lead as regards number of species knownto serve as intermediate hosts for parasitic worms, as there are 186species of insects, 'JJ species of crustaceans, 6 species of arachnids,and only 2 species of myriapods included in these lists of intermediatehosts. The total number of arthropod species listed here as inter-mediate hosts for the worm groups involved is 271.CONCLUSIONIt should be reiterated that one must not draw too sweeping con-clusions in regard to the importance of host groups or in regard to 70 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l several other things at this time. For one thing, the lists given hereare such as could be compiled in the time at the writer's disposal andwhile reasonably comprehensive must necessarily be incomplete. Foranother thing, our total knowledge in regard to the life histories ofheteroxenous helminths is very slight. As already stated, we know thelife histories of approximately i per cent of the known tapeworms,and this status is sufficiently representative of conditions for all heter-oxenous worm groups to need no detailed statement in regard tothe other groups. There may be important intermediate host groupsof which no member has yet been incriminated. We know about 143life histories involving arthropods ; there are certainly hundreds, per-haps thousands, of such life histories still to be ascertained.Admitting all of these defects in our data, we are neverthelessjustified in saying that the lists presented here will be of value inaffording the student a clue as to the probabilities in beginning asearch for the intermediate host of a heteroxenous worm parasite, orin considering the probable identity of a larval worm found in anarthropod. This will fulfill one of the purposes of this paper—to aidthe student. The young students of to-day will include among theirranks the competent scientists of to-morrow.Another purpose of this paper is to point out the opportunities forcooperation among scientists in adding to our knowledge of the lifehistories of parasitic worms. Zwaluwenberg, an entomologist, has saidrecently : " The interrelationships of insects and nematodes is asubject of which most entomologists seem to have little adequateconception." Some months ago, in discussing the scope of this paperwith Dr. L. O. Howard, the writer told him that he expected to callattention to the fact that our knowledge of these life histories hadcome almost entirely from the parasitologists, and that the workerson insects and crustaceans had aided very little in the process. Dr.Howard, characteristically, suggested that this be done very diplo-matically. It is the writer's intention to do this diplomatically. It isprimarily the business of the parasitologist to ascertain the life his-tories of the parasites with which he deals. It would not be in orderto ask the specialist on insects or crustaceans to ascertain the lifehistories of the larval worms which he finds in these insects andcrustaceans, nor would it add greatly to our knowledge to have per-sons unfamiliar with parasitic worms publish findings in an unfamiliarfield.Nevertheless, there is an opportunity for cooperation between theworkers on parasitic helminths and the workers on their arthropodhosts, and little advantage has been taken of this fact in the past. ("^ NO. 15 ARTHROPOD HOSTS OF HELMINTHS HALL 71My friend, Dr. Wm. A. Riley, has called my attention to Stein'spioneer contributions ; conceding the point, Stein's good example hasnot been followed by most entomologists. The competent worker ineither field should be primarily a zoologist, and as such able to seethe possibilities for cooperation with other zoologists in connectionwith incidental findings which come to his attention. The larvalhelminth in an arthropod is an animal which concerns the helmin-thologist in one direction and the " arthropodologist " in another. Asound consideration of the worm calls for a sound consideration ofits host, and vice versa. Prophylactic measures directed against het-eroxenous worms call for control measures for intermediate hosts, andif this host is an arthropod the helminthologist must draw on theknowledge of the man who knows about arthropods.One of the promising developments in this connection is the factthat whereas the entomologist in the past has devoted his attention tothe outside of the insects with only casual attention to the internalanatomy, there is now a tendency to devote more attention to theinternal structures. In examining the interior of the insects, theentomologist is certain to find larval worms in some of them. In suchcases he would be rendering a service if he would do one of the fol-lowing things:If the entomologist is well trained in zoology, and has the time,facilities, and inclination to carry out an adequate investigation ofthese worms, he can proceed with feeding experiments and ascertainthe life history. Lacking the training, time, facilities, or inclination toto do such work, he can turn the material over to a parasitologist forinvestigation, or call attention in his publications to his findings inorder that they may serve as a guide to the parasitologist who isworking along this line.Some of the hosts given in this paper are not well established, butare included for completeness. In establishing a life history for aparasitic worm, one may be guided with profit by the remarks ofStiles in 1896 in connection with the life histories of bird tapeworms : The known or supposed life history has been based upon four different methodsof work, i. e. :1. Experimental infection of the fowls by feeding to them known larval stagesfound in invertebrates, and thus raising the adult stage.2. Experimental infection of invertebrates by feeding to them the eggs oftapeworms found in birds, and thus raising the larval stage.3. Comparison of the hooks upon the heads of adult tapeworms of birds withthe hooks of larvae found in invertebrates, and thus associating the young andthe old stages.4. Wild speculations as to the intermediate hosts, based upon negative resultsand totally devoid of any scientific foundation. 72 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8lOf these four methods of work the first two give positive proof of the lifehistory when the experiments are successful ; the third gives a probability to thestatements, but not a proof ; the less said about the fourth method the better.In this later epoch it is advisable to establish a life history by bothof the first methods, not ignoring the third, if adequate evidence isdesired. Raising Diphyllohothr'mm latum in dogs by feeding plerocer-coids from fish did not show that a copepod was the first host ; failureto infect fish with the tapeworm eggs necessitated further search andso led to the discovery of the copepod host. Another thing deservesemphasis : Finding that one arthropod is an intermediate host doesnot settle the problem of a life history of a worm. The worm mayhave a score of intermediate hosts, and the most important one maynot be an arthropod. ADDENDUMSince the foregoing was written the following records have cometo hand and are given here without discussion : LIST BY PARASITES(Crust. ^ Crustacea)CESTODACESTODARIAAmphilina foliacca—Corophiu»i citrvispinum ; Crust.; AmphipodaDikerogammariis haemobaphes ; Crust. ; AmphipodaGammarus platycheir; Crust. ; AmphipodaMctamysis strauchi; Crust. ; Mysidacea DIPHYLLOBOTHRIIDAEDiphyllobothrium ranarum—Cyclops fuscus; Crust. ; CopepodaDiphyllobothrhim decipiens—Cyclops sp. ; Crust. ; CopepodaDiphyllobothrium erinacei—Cyclops sp. ; Crust. ; CopepodaDiphyllobothrium mansoni—Cyclops sp. ; Crust. ; CopepodaCyclops strenuus; Crust ; CopepodaPROTEOCEPHALIDAEProteocephalus amblopUtis—Hyalella asteca; Crust.; AmphipodaCyclops serrulatus; Crust. ; CopepodaCyclops viridis; Crust. ; CopepodaProteocephalus pingiiis—Cyclops serrulatus; Crust. ; CopepodaCyclops viridis; Crust. ; CopepodaOphiotaenia testudo—Cyclops sp. ; Crust. ; Copepoda \l\ NO. 15 ARTHROPOD HOSTS OF HELMINTHS—HALL 73CESTODA (Continued)HYMENOLEPIDIDAEHymenolepis collaris—Cypris sp., Crust. ; OstracodaHymenolepis anatina—Cypris sp. ; Crust. ; OstracodaHymenolepis corontila—Cypris sp. ; Crust. ; OstracodaHymenolepis carioca—Choeridium histeroides; Insecta ; ColeopteraHister (Carcinops) 14-striatus; Insecta; ColeopteraAnisotarsiis agilis; Insecta; Coleopterat Choanotaenia infiindibidum—Cratacanthus dubitts; Insecta ; Coleoptera *DAVAINIIDAERaiUictina cesticillns—Anisotarsiis agilis; Insecta ; ColeopteraAnisotarsiis tcrminatus ; Insecta ; ColeopteraChoeridium histeroides; Insecta ; ColeopteraAphodius granarius; Insecta ; Coleoptera *Selenophorus ovalis; Insecta ; Coleoptera *Selenophorus pedicularis; Insecta; ColeopteraTriplectrus riisticus ; Insecta ; Coleoptera *TREMATODAPLAGIORCHIIDAEPlagiorchis macxilosits—Chironomus plumosus; Insecta; DipteraChironomiis sp. ; Insecta ; DipteraHETEROPHYIDAEMicrophallus minus—Macrohrachiiim nipponensis; Crust. ; DecapodaTROGLOTREMATIDAEParagonimus westermani—Camharoidcs daimricus; Crust. ; DecapodaEriocheir sinensis; Crust. ; DecapodaFAMILY UNCERTAINDistome of Eckstein — Culex pipiens; Insecta; DipteraMetacercaria of Joyeux, 1928 — Anopheles maculipennis; Insecta; DipteraCercaria X.i of Harper, 1929 Gammarus pulex; Crust.; AmphipodaOrchestia littorea; Crust. ; AmphipodaChironomus plumosus; Insecta; DipteraCulex pipiens; Insecta; DipteraTipula maxima; Insecta ; DipteraPedicia rivosa; Insecta; DipteraDysticus marginalis; Insecta; ColeopteraSialis lutarius; Insecta ; DipteraHalesus sp. ; Insecta ; TrichopteraLimnophilus centralis; Insecta ; TrichopteraLimnophilus rhombicus; Insecta ; TrichopteraPlectrocnemia conspersa; Insecta; TrichopteraRhyacophila dorsalis; Insecta; Trichoptera * Unpublished work by M. F. Jones. 74 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8lNEMATODASPIRURIDAEGongylonema ingluvicola—Copris niinutus; Insecta; Coleoptera *Phanaeus carnifex—Insecta ; Coleoptera *Fhysocephalus se.valaius—Canthon lacvis; Insecta ; ColeopteraGymnopleurus sinnatiis; Insecta ; ColeopteraPhanaeus carnifex; Insecta; ColeopteraLarval splrurid (?) — Campodca sp. ; Insecta; ThysanuraPHYSALOPTERIDAEProleplus scUlicula—Carcinus maenas ; Crust. ; DecapodaEttpagurus bcrnhardus ; Crust. ; DecapodaACUARIIDAECheilospiriira hamulosa—Melanoplus fcmurrubniin; Insecta; Orthoptera *Cheilospirtira spinosa—Melanoplus femurrubrum; Insecta; Orthoptera .-Icnaria anthurts—Melanoplus femurrubrum; Insecta; Orthoptera*Crickets ; Insecta ; Orthoptera *TETRAMERIDAETetrameres amcricana—Melanoplus differentialis; Insecta ; OrthopteraMelanoplus femurrubrum; Insecta ; Orthoptera *FILARIIDAEIVuchereria bancrojti—Acdes alb olaterails; Insecta ; DipteraAedes chemulpoensis; Insecta ; DipteraAedes galloisi; Insecta; DipteraAedes subpictus; Insecta; DipteraArmigeres obturbans; Insecta; DipteraCulex anmilus; Insecta ; DipteraCulex bilaeniorhynchus karatsuensis; Insecta ; DipteraCulex japoniciis; Insecta; DipteraCulex pipiens pallens; Insecta ; DipteraCulex tipuliformis; Insecta; DipteraCulex tripunctatus; Insecta; DipteraCulex tritaeniorhynchus; Insecta; DipteraCulex whitmorei; Insecta; DipteraDRACUNCULIDAEPhilometra nodulosa—Cyclops brevispinosus; Crust.; CopepodaFAMILY UNCERTAINCystopsis accipenseris—Dikeroganimarus haemobaphes; Crust. ; AmphipodaGammarus platycheir; Crust. ; AmphipodaCyclopsinema mordens—Pachycyclops signatus; Crust. ; Copepoda * Unpublished work of E. B. Cram. NO. 15 ARTHROPOD HOSTS OF HELMINTHS HALL 7-LIST BY HOSTS(Cest. = Cestoda; Trem. = Trematoda ; Nem. =: Nematoda)CRUSTACEAAMPHIPODACorophuim curvispinum—AmphiUna foliacea; Cest. ; CestodariaDikcrogammarm baemobaphes—Amphilina foliacea; Cest. ; CestodariaCystopsis accipenseris; Nem. ; Family ?Gammarus platycheir—AmphUina foliacea; Cest. ; Cestodaria.Cystopsis accipenseris; Nem.; Family?Hyalella a::teca—Protcocephaliis ambloplitis; Cest.; Proteocephalidae COPEPODACyclops brevispinosus—Philomctra nodulosa; Nem. ; DracunculidaeCyclops fuscus—Diphyllohothrium ranarum; Cest. ; DiphyllobothriidaeCyclops serrulatus—Proteocephalus pinguis; Cest. ; ProteocephalidaeProteoccphaliis ambloplitis; Cest. ; ProteocephalidaeCyclops sp. — Diphyllobothrium decipiens; Cest. ; DiphyllobothriidaeDiphyllobothriiim erinacei; Cest. ; DiphyllobothriidaeOphiotaenia testudo; Cest. ; ProteocephalidaeCyclops strenuus—Diphyllobothrium mansoni; Cest. ; DiphyllobothriidaeCyclops viridis—Proteoccphaliis pinguis; Cest. ; ProteocephalidaeProteocephalus ambloplitis; Cest. ; ProteocephalidaeMacrocyclops signatus—Cyclopsincma mordcns; Nem.; Family?Pachyclops signatus—See Macrocyclops signatus Cambaroidcs dauuricus—Paragonimus zvcsterviani; Trem. ; TroglotrcmatidacCarcinides (Carcinus) macnas—Prolepttis scillicola; Nem.; PhysalopteridaeCarcinus maenas—See Carcinides {Carcinus) maenasEriocheir sinensis—Paragonimus zvestermani; Trem. ; TroglotrcmatidaeEupagurus bcrnhardus—See Pagurus bcrnhardns.Macrobrachium nipponensis—Microphallus minus; Trem. ; HeterophyidaePagurus bcrnhardus—Prolcptus scillicola; Nem.; Physalopteridae MYSIDACEAMetamysis sirauchi—Amphilina foliacea; Cest. ; CestodariaOSTRACOBACypris sp. — Hymcnolcpis anaiina: Cest.; HymenolepididacHymenolcpis collaris; Cest. ; HymenolepididacHymcnolepis coromda; Cest. ; Hymenolepididac 76 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 8lINSECTACOLEOPTERAAiiisotarsiis ac/ilis—Raillictina ccsficilltis; Cest. ; DavainiidaeHyincnolepis carioca; Cest.; HymenolepididaeAnisotarsHs tcnninahis—RaiUietina cesticillus; Cest.; DavainiidaeAphodiits granarius—RaiUietina cesticillus; Cest. ; DavainiidaeCanthon lacvis—Physocephalus scxalatus; Nem. ; SpiruridaeChoeridinni histcroidcs—RaiUietina cesticillus; Cest.; DavainiidaeHymenolepis carioca; Cest. ; HymenolepididaeCopris Jiiiniitus—Gongylonema ingluvicola; Nem.; SpiruridaeCratacantlms dubius—? Choanotacnia infimdibidum; Cest.; HymenolepididaeDysticus niarginalis—Cercaria X.i of Harper, 1929; Trem. ; Family?Gymnoplenrus simtatus—See Gytnnopleurus sinuatusGymnopleurus sinuatus—Spirocerca sanguinolenta; Nem. ; SpiruridaeHister (Carcinops) 14-striatus—Hymenolepis carioca; Cest.; HymenolepididaePhanaeus carnifex—See PJianaeus vindexPhanaeus vindex—Gongylonema ingluvicola; Nem.; SpiruridaePhysocephalus sexalatus; Nem. ; SpiruridaeSelenophorus ovalis—RaiUietina cesticillus; Cest. ; DavainiidaeSelenophorus pedicularis—RaiUietina cesticillus; Cest. ; DavainiidaeTripledrus rusticus—Raillictina cesticillus; Cest. ; DavainiidaeNEUROPTERASialis lutarius—See Sialis flainlateraSialis flavilatera—Cercaria X.i of Harper, 1929; Trem.; Family?TRICHOPTERAHalesus sp.—Cercaria X.i of Harper, 1929; Trem.; Family?Limnophilns centralis—Cercaria X.i of Harper, 1929; Trem.; Family?Limnophilus rhombiciis—Cercaria X.i of Harper, 1929; Trem.; Family?Plectrocnemia conspersa—Cercaria X.i of Harper, 1929; Trem.; Family?Rhyacophila dorsalis—Cercaria X.i of Harper, 1929; Trem.; Family? Aedes albolateralis—Wuchereria bancrofti; Nem. ; FilariidaeAedes chemulpoensis—Wuchereria bancrofti; Nem. ; FilariidaeAedes galloisi—Wuchereria bancrofti—Nem. ; FilariidaeAnopheles maculipennis—Metacercaria of Joyeux, 1928; Trem.; Family:Anopheles rossi—See Anopheles subpictusAnopheles subpictus—Wuchereria bancrofti; Nem. ; FilariidaeArmigeres obturbans—See Desvoidya obturbansChironomits pliinwsus—Plagiorchis maculosus ; Trem. ; PlagiorchiidaeCercaria X.i of Harper, 1929; Trem.; Family?Chironomus sp. — Plagiorchis maculosus ; Trem. ; PlagiorchiidaeCulex ammlus—See Ctdex tritaeniorhynchus NO. 15 ARTHROPOD HOSTS OF HELMINTHS HALL 'JJINSECTA {Continued) niPTERA (Continued)Culcx bitaeniorhynchus karatsuensis—Wuchereria bancrofti; Nein. ; FilariidaeCulex japonicus—Wuchereria bancrofti; Nem. ; FilariidaeCulex pipiens—Distome of Eckstein ; Trem. ; Family ?Cercaria X.i of Harper, 1929; Trem.; Family?Wuchereria bancrofti ; Nem. ; FilariidaeCulex pipiens pallens—See Culex pipiensCulex tipuliformis—Wuchereria bancrofti; Nem. ; FilariidaeCulex tripunctatus—Wuchereria bancrofti ; Nem. ; FilariidaeCulex tritaeniorhynchus—Wuchereria bancrofti; Nem. ; FilariidaeCulex whitmorei—Wuchereria bancrofti; Nem. ; FilariidaeDesvoidya obturbans—Wuchereria bancrofti; Nem. ; FilariidaeTipula maxima—Cercaria X.i of Harper, 1929; Trem.; Family?Pedicia rivosa—Cercaria X.i of Harper, 1929; Trem.; Family?THYSANURACampodea sp.—Larval spirurid (?); Nem.; Spiruridae?ORTHOPTERACricket — Acuaria anthuris; Nem. ; AcuariidaeMelanoplus different ialis—Tetrameres atnericana; Nem. ; TetrameridaeMelanoplus femurrnbrum—Tetrameres americana; Nem. ; TetrameridaeCheilospirura hamulosa; Nem. ; AcuariidaeCheilospirura spinosa; Nem.; AcuariidaeAcuaria anthuris; Nem.; Acuariidae