GALL WASPS 



298$ 



round the eggs of a moth, ready to insert their own. The females usually de- 

 posit their eggs in those of the family Bombycidce, as, for instance, those of the 

 common lackey. 



Family 



This group includes a large number of small brightly-colored insects with 

 metallic lustre; nearly three thousand European species being known, while the 

 tropics have not yet furnished their contingent of species. The antennae are always 

 elbowed, and the wings broad with few nervures. Some of the larvae live in galls, 

 devouring the grub of the gall wasp or those of the other inhabitants of the galls. 

 The members of the present order, scale insects and plant lice, are alike subject to 

 the attacks of the species of this family. One species {Leucopsis gigas) found in 

 Southern Europe lays its eggs in the larvae of a mason bee, which makes a cell of 

 hard cement to protect its grub. Now the attacker has a boring apparatus, and the 

 problem is how to ascertain the whereabouts of a grub, bore through the hard 

 masonry, and lay eggs in the inmate. The cells are not distinct; but the whole 



] 3 2 



1. GOUTY-LEGGED WASP; 2. CHRYSALIS STINGER; 3. Sketches of various Chalcididcz (enlarged). 



number, which are made in a sort of colony, are covered with cement, so that the 

 task is doubly difficult. With the divining powers apparently situate in the 

 antennae, a suitable spot is chosen, and after, it may be, an hour or so of con- 

 tinuous boring, the succulent morsel is reached and the egg laid. How the wasp 

 knows where the grub lies is not known. It seems to have the power if not of 

 seeing at any rate of feeling literally through a brick wall. One of the largest 

 members of the family is the gouty-legged wasp (Smicra clavipes), the egg of which 

 is laid in the larvae of certain water insects. The wasp is glistening black, with 

 reddish legs, the wings being better furnished with nervures than in other mem- 

 bers of the family. In the chrysalis stinger (Pteromalus puparum) the egg is laid 

 in the chrysalis of several common butterflies during summer, while the larvae 

 remain in their host all through the winter, sometimes to the number of fifty. 



