ENTOMOLOGY

DISEASES TRANSMITTED BY MOSQUITOES ~61r08sU. Fish swallowing the mosquito larvre take up the worm, whichcontinues its development toward maturity. 'The final host is notknown.N emathelmm.the8 : Nematoda: Filariidae 2Acamthocheilonema per8tans (Manson 1891), the cause of a f'l.rm ofhuman FILARIASIS in Africa, is probably carried by biting flies.Hodges in Uganda obtained an incomplete cycle in Man8onioide8 africa'TlllMlTheobald (Panoplite), Aede8 argentcus (calopUlJ) , A. sugens 'Viedemann,Anophele8 costalia Loew, and a Culex, and negative results with a longseries of mosquitoes (Dye, 1905). Low (1903) obtained incomplete developmentin Taeniorhynchu8 fU8copcnnatUlJ.Dirofilaria immitia (Leidy, 1856), cause of CANINE FILARIASIS,has been provcn by NOEl, Dye (1908), Grassi, and Fiilleborn (191~) topass its intcrmediate stages in the following mosquitoes-Anophelesmaculipenmis Meigen (claviger Fabricius), A. algeriensis Theobald, A.-bifurcatus Linnaeus, A. sinensis Wiedemann (pseudopictUlJ Grassi), A.superpictus Grassi, Culex quinquefa8ciatus Say (fatigans Wiedemann),C. malariO! Grassi, C. penicillaris Rondani, and Aedes vexans Meigen(Culex) exceptionally in C. pipiens, and with difficulty in Aedes argentcus(Stegomyia calopus). The microfilaria or embryo worms are taken upby the mosquito with the blood of the dog. They soon pass from thestomach into the Malpighian tubules. In ten days their development iscomplete and they migrate towards the head and into the proboscis.When an infected mosquito containing filarire in its proboscis feeds on adog, the worms escape by boring through a delicate membrane whichunites the labellre, and thus get on the surface of the skin. If this is sufficientlymoist they penetrate the epidermis and may be found in the subcutaneoustissues, whence they work toward the heart and great vesselsof the dog and there develop into adults.Dirofilaria repens Railliet and Henry (1911), cause of SUB­CUTANEOUS CANINE FILIARIASIS, passes its intermediate stagesin the mosquito Aedes argenteus, its development having been demonstratedby Bernard and Bauche (1913). Its life history is quite similarto that of D. immitis.Filaria bancrofti Cobbold' (1877), the cause of. HUMAN FILARIA­SIS or ELEPHANTIASIS, passes its intermediate stages in the mosquitoes.Complete development. has been demonstrated in Anopheles r088;Giles in India by James; A. c08talia Loew in West Africa by Annett,Dutton, and Elliot; Culex pipiena in China by Manson; C. quinquefa8ciatusSay (fatigans Wiedemann, ciliari8 Bancroft, nigrithorax 8k1l,8ei Giles)in China by Manson, in South Carolina by Francis, in Australia by Ban-I For further discussion of the following worms see Chapter V.