222 



INSECT TRANSFORMATION 



haphazard on leaves of trees where the host caterpillars are feed- 

 ing (Fig. in a), so that these may swallow them as they eat the 

 leaves. The Blepharipa maggots (Fig. in b) eat through the 



a 



FIG. III. 



a, Eggs of Tachinid-Fly (Blepharta scutellata) on leaf, x 5. 6, first stage larva with mouth- 

 hooks ; c, c, first stage larvae in modified tissues of their host-caterpillar ; d, second stage larva 

 with its tail-end in tracheal " funnel " of host close to spiracle, x 25. From Howard and Fiske. 



wall of the food-canal in which they are hatched, and embed 

 themselves in the caterpillar's tissues which appear to undergo 

 an abnormal gall-like growth (Fig. me) as the result of their 

 presence. After a moult they are found in enlarged and 



