DIPTERA (two-winged FLIEs). 79 



The larvae of the Bot-flies and Gad- or Warble- flies {CEstridce) 

 are rtiammal pai'cisites. They are white and grublike in shape, 

 and live in the nostrils, frontal sinuses, pharynx, stomach and 

 intestine, or beneath the skin. The majority are parasitic upon 

 Ungulates ; but the larvae belonging to the American genus 

 Cittiterehra are found beneath the skin of Kodents. It may be 

 noted that larvae belonging to this family rarely survive forcible 

 removal from the host. Pupation invariably takes place upon or in 

 the ground, under stones, etc. ; therefore, in order to breed out the 

 perfect insects, an attempt should be made to obtain the larvae as 

 they leave the host in order to pupate, or the pupae themselves 

 should be sought for in the situations indicated, in places frequented 

 by the animals. In the case of domestic or other animals, kept in 

 captivity and infested by these parasites, the pupae or larvae about to 

 pupate may sometimes be obtained by searching in the stalls or 

 sheds at the proper season. According to Brauer the majority of 

 CEstrid larvae leave their hosts in the early hours of the morning. 



The larvae of the Muscidce (sensil latior^e) are 

 well known as maggots, and are to be found in 

 decaying matter of all kinds, and even in fes- 

 tering sores and wounds on living animals ; 

 those of the sub-family Tachiniyice are parasitic 

 in other insects — the majority in caterpillars. 



FABRICtA FEROX. 



^ The habits of the larvae belonging to the families constituting the 

 Acalypterate Muscidce are too diversified to be dealt with in detail. 

 Some are to be found in ordure; others attack the stems of grasses 

 and cereals; while the larvae of others again (e.g. TrypetidiK) live in 

 fruits, in seed-heads, in galls on tJie stems, or mine in the leaves of 

 various plants. 



How TO Preserve Larvae. 



Specimens of larvae will always be valuable, whenever it is 

 possible to breed out some of them so as to determine the fly to 

 which they belong. Unless, however, the perfect insect is known, it 

 is rarely possible to do more than to determine the family or genus 



