THE BOT-FLIES. 



635 



yellowish, with brown nervures. Some of these insects were 

 hatched from larvse found attached to the pupoe of ladybirds. 



The larvse of these Flies are found to feed on various 

 substances, some being believed to be parasitic on other larvae, 

 and others having been observed to feed on vegetable sub- 

 stances. For example, the larva of one species, Phora daucl, 



LXXVI 



1. Phora abdominalis. 2. Omit'hom3'ia fringillai-ia. a. Phora abdominalis : head, 



side view. b. Do., leg. c. Oniithomyia fringillaria, leg. d. Do., maxilla. 



was seen to feed upon the interior of decaying radish-roots. 

 The larva is nearly cylindrical in shape, but is slightly nar- 

 rowed in front. The last segment of the body has eight 

 radiating points, like those of the one or two larvse which have 

 been described, and there are also two spiracles on the same 

 segment. 



We now come to the small but important family of the 

 CEstridse, popularly known as Bot-Flies. In these insects the 



