HOW TO KNOW THE IMMATURE INSECTS 

 18a. Posterior spiracles situated upon apical segment, . . 



19 



18b. Posterior spiracles situated upon penultimate or antepenultimate 

 segment 23 



19a. Projecting portion of head and flattened apical plate of terminal 

 abdominal segment heavily sclerotized/ the former cone-shaped, 

 entirely closed except at extreme apex, not retractile; the latter 

 obliquely tnmcate and with projecting processes. 

 Fig. 549 Family XYLOPHAGIDAE 



r^'ss 



The larvae ore found in the soil or imder the bark 

 of rotten trees. They feed upon the larvae of other 

 insects. 



The members of this small family ore related to the 

 better known soldier flies and to the horseflies. 



Fig. 549. Xylo- 

 phagus lugens 



Loew. 



19b. Projecting portion of head more or less retractile, not cone-shaped, 

 the movable portion not enclosed; apical abdominal segment 

 without a heavily sclerotized flattened terminal plate 20 



20a. Apical abdominal segment ending in 2 long processes which are 

 fringed with long soft hairs; abdomen with paired pseudopods and 

 fleshy dorsal and lateral appendages. 

 Fig. 550 FamUy RHAGIONIDAE 



Some larvae live in fresh 

 water with flattened body 

 while others live in dung, 

 wood or fungi with cylindri- 

 cal body. They ore preda- 

 cious and feed on small ani- 

 mals. Some Vermileo can 

 make ant-trapping pits in 

 dust or sand similar to those 

 of the ant-lions. The adults 

 are known as snipe flies. 



196 



Fig. 550. Atherix sp. 



