THE DIJPTEROUS PARASITES OF ALETIA. 



107 



struction of the worms. This species — comstocldi — is by no means 

 confined in its attacks to Aletia larvse, but has been bred from or 



Fig. 35. — Euplectrus comstockii: female. (After Comstock.) 



found upon Frodenia lineatella and Laphygmafniglperda. From the La- 

 phygma twenty-five parasites were reared from a single larva. 



The common Flesh-ply. — Several species of flies belonging to well- 

 known parasitic genera have been found to infest the worm. One of 

 these is the common Flesh-fly, and a male specimen bred from Aletia 

 does not differ^^ materially from small specimens obtained from the 

 decaying insects found in the pitchers of the spotted i3itcher-plant 



{Sarracenia variolayns)^ and to which 

 we have given the name of Sarcophaga 

 sarracenice. 



These flies (Fig. 36) lay elongate and 

 delicate eggs, which hatch very quickly. 

 They sometimes hatch, in fact, within 

 the oviduct, so that the fly gives birth 

 to living maggots. The maggot pen- 

 etrates the skin of the worm or the 



&, pnj)a ; c. fly, thu liaiv liuf.s .showin 



na mal lengths 



1 nl iji<hI h; ad and liist 



joint or laiva, shouin-icu-ve.lli.)()k.>*. lower lip pl.T-vcolw ntj tl^A Pii<SA rmv hp iTifl fppfl<5 



((]) and prothoiaric spiracle; e, end (.f body <-Ljr;\ Sdllb, aSlUC CaSC may DC, dUtl leCUS 



of sa7ue, showlnj; stiirmata (/) and prologs nnnn Hipftit-fx- fwcnpc witliiTi npnnirino- 



and v. nt: /^ tarsal claws of fly with protec^t- i^POU lUeiaity ILsSUCS M ItUm, acqUlllUg 



'(After Riie!i-.r*'°''^ °* ■'*'"^" ^^^ ^^^^^^ed. f^]} growth aud issuiug sometimes be- 

 fore but usually after its victim has 

 transformed to the chrj'salis state. Dropping to the ground, it burrows 

 beneath the surface, aud rapidly contracts to the pupa state, from which 

 the perfect fly in due time issues. The species has been obtained from 

 the Cotton AVorm in Alabama, Georgia, and Texas, and is indeed wide- 

 spread over the country. It is most abundant in autumn, and passes 



