228 INSECT TRANSFORMATION 



having the female's ovipositor modified into a sting, as is the 

 case also with the wasps, bees and ants. These digging-wasps 

 capture caterpillars, grasshoppers, crickets, spiders, or other 

 creatures each genus having its own specially appropriate 

 prey which they sting so as to paralyze, and then bury in 

 the ground, laying eggs on their bodies. The digging-wasp's 

 larvae when hatched proceed to devour the victims, and their 

 manner of feeding is, as a whole, closely like that of the ichneu- 

 monoid larvae except that they attack the victim from outside, 

 not from within. Species of Bembex, which also belong to 

 this group, furnish, at the time of egg-laying, enough supply of 

 food to serve the larvae during the earlier stages of their 

 growth ; later on the females catch flies wherewith they feed 

 their grubs as a mother-bird her nestlings, till they attain 

 their full growth, and are ready for pupation. Here the 

 insects are evidently hunters, and their larvae cannot be truly 

 described as parasites. 



Many insect-larvae, having no such maternal care as is dis- 

 played by the Bembecines, are themselves active little beasts of 

 prey. Reference has already been made (p. 109) to the grubs 

 of ground-beetles, which run after insects in the soil, and those 

 of lady-birds (p. 109) which leisurely devour " green-fly ' 

 on plants, in much the same way as their parent beetles do. 

 Many other beetle larvae are carnivorous, such as those of the 

 dyticid water-beetles which pierce and suck tadpoles and other 

 aquatic creatures, the " glowworm " which attacks snails and 

 slugs, and those of the rove-beetles (Staphylinidae) which hunt 

 plant-feeding grubs in the soil or in timber-galleries. Almost 

 all these predatory larvae are of the well-armoured, long- 

 legged type that shows the least marked difference from the 

 adult form. It is of especial interest to notice this predaceous 

 habit among larvae of other types, which have to make their 

 own way in the world. The adaptation of the maggot for 

 active carnivorous habits is well shown in the larvae of the 

 hover-flies (Syrphi) graceful, little, yellow-banded flies which 

 poise themselves over flowers. Their maggots, like the lady- 

 bird grubs, live on plants and devour " green-fly " which they 

 impale on their mouth-hooks. The Syrphus larva (Fig. 115), 

 has the cuticle tougher than that of an ordinary scavenging 

 or plant-feeding maggot, tuberculate and wrinkled, not pale 



