n6 



Parasitic Arikropoda 



The different types of larvae represented in figure 81 were formerly 

 supposed to belong to different species but Blanchard regards them 



as merely various stages 

 of the same species. It 

 is only very recently 

 that the early stage and 

 the method by which 

 man becomes infested 

 were made known. 



About 1900, Blanch- 

 ard observed the pres- 

 ence of packets of large- 

 sized eggs under the 

 abdomen of certain mos- 



83. Dermatobia cyaniventris (xl^). After Graham-Smith. 



quitoes from Central 

 America; and in 1910, 



Dr. Morales, of Costa Rica, declared that the Dermatobia deposited 



its eggs directly under the abdomen of the mosquito and that they 



were thus carried to vertebrates. 



Dr. Nunez Tovar observed the 



mosquito carriers of the eggs and 



placing larvse from this source on 



animals, produced typical tumors 



and reared the adult flies. It 



remained for Surcouf (1913) to 



work out the full details. He 



found that the Dermatobia de- 

 posits its eggs in packets covered 



by a very viscid substance, on 



leaves. These become attached 



to mosquitoes of the species 



Janthinosoma lutzi (fig. 84) which 



walk over the leaves. The eggs 



which adhere to the abdomen, 



remain attached and a're thus 



transported. The embryo de- 

 velops, but the young larva (fig. 82) remains in the egg until it has 



opportunity to drop upon a vertebrate fed upon by the mosquito. 



84. 



Mosquito carrying eggs of Dermatobia 

 cyaniventris. After Surcouf. 



