Julv — September 1SS5.] 



j'src/zB. 



305 



THE LARVAE OF OESTRIDAE. 



BY FRIEDRICH BRAUliK, VIENNA, AUSTRIA. 



[Tr:insl;ited by B '■ Pickinan Mann from Fricdrich Braufr's "Mnnoj^rapliit; der ocstiidcii," Wien, 1S63, p. ,^5-40.] 



The huvac of tiie ocstridac. although 

 in many cases quite peculiarly shaped, 

 are so nearly related to the larvae of 

 the rest of the niitscidae-calvpterci 

 that it has not jxt been possible to dis- 

 cover for them a constant distinguish- 

 ing character founded upon their struc- 

 ture. The reason of this lies in ]3art 

 in the oestrid larvae themselves, since 

 they are very different among them- 

 selves, and in part also in our defective 

 knowledge of the muscid larvae. 



At present, it is true, no real muscid 

 larvae are known with large thorn- 

 warts, — as I will call the dermal for- 

 mations which occur in many oestrid 

 larvae, which are conical, soft at the 

 base, fleshy, and corneous at the tip, — 

 also none with the characteristic stig- 

 mata 1 plate of the Gastrophihis lar- 

 vae ; on the other hand very man3' are 

 known with thorn.s, like those oi Der- 

 matobia, or naked, like those of the 

 young J-fypoderma, or with hornv 

 stigmatal plates, like those of Cephe- 

 nomyia. The remarkable parasitic 

 method of life in mammals can prob- 

 ably be looked upon as peculiar to the 

 oestridae. I leave it therefore to a 

 future observer to estal)lish a character 

 for the oestrid larvae whereby thev 

 may be distinguished from all other 

 muscid larvae, and limit mvself here 



to the (.lescription of the larvae accord- 

 ing to genera and species. 



The oestrid larvae belong to the 

 great division of those dipterous niag- 

 gots which have been called headless, 

 since they are segmented throughout 

 and the usual regions of the insect bod}' 

 are not separated. Only a cephalic 

 and an anal end, therefore, can be dis- 

 tinginshed on the annidate body of such 

 larvae. In general the following com- 

 mon characters and pecidiarities of the 

 oestrid larvae cm be specified. 



1. The body of all oestrid larvae is 

 reallv composed of twelve rings. The 

 lirst two are however not always dis- 

 tinctly separated, so that I take them 

 together in the description, and desig- 

 nate them both liv the name of cephalic 

 ring, on which in many cases an an- 

 terior and posterior section is clearly 

 to be distinguished. On that account I 

 assume only eleven segments, as earlier 

 authors have done. Onlv the new- 

 born larvae of Gastrophihis make an 

 exception to this number ; they, if 

 July's statement is correct, possessing 

 thirteen segments. 



2. Two anterior, external breathing- 

 organs are always to be distinguished 

 on the larvae, between tiie first and 

 second segments of the body, and two 

 posterior, external breathing-organs on 



