6 14 THE STUDY OF INSECTS. 



male deposits her eggs on the under side of the first leaves 

 that appear on the currant ; the eggs are glossy and white, 

 and are placed in rows along the ribs of the leaf. In ten 

 days the larva hatches ; it is at first whitish, with a big head ; 

 it grows fast, and soon becomes green, and then has black 

 dots and a black head, and looks like a caterpillar. A 

 brood will strip a bush of all its leaves. The larva spins 

 a brownish paper-like cocoon, sometimes fastening it to the 

 stripped bush, and sometimes making it just below the sur- 

 face of the ground. There are two broods, and as the flies 

 of one brood do not issue all at the same time, the fight 

 against them must be pretty constant. Hellibore or Paris- 

 green are the substances commonly used to destroy this in- 

 sect. There is a native saw-fly on currents that has much 

 the same habits. 



Family SIRICID.E (Si-ric'i-dae). 

 The Horn-tails. 



These are so named because in this family the end of 

 the body usually bears a spine or horn. This is short and 

 triangular in the males, and long and often spear-shaped in 

 the females. The horn-tails are closely related to the saw- 

 flies, but differ from them in the shape of the ovipositor, 

 which is made for boring instead of sawing, and in the 

 habits of the larvae, which are borers in solid wood. 



The ovipositor consists of five long slender pieces ; the 

 two outside pieces are grooved on the inner surface, and 

 when joined make a sheath containing the other three 

 pieces ; one of these is nearly cylindrical, and is channelled 

 beneath for the reception of the other two, which are very 

 slender and stiff, and furnished at the tip with transverse 

 ridges, like the teeth of a file. With this complex instru- 

 ment the female can bore a deep hole into a tree and place 

 an egg at the bottom of it. 



There are several species of horn-tails in America. A 



