90 INSECTS 



The Raphidiidcc are very curious creatures peculiar 

 to the Pacific Coast, in which the head and prothorax 

 of the adult are greatly elongated and it, as well as 

 the slender elongated larva, is predatory. In the pre- 

 ceding families, while the larvae are voracious feeders, 

 the adults feed little or not at all. 



The Mantispida are similar to the Raphidiidce in 

 the elongation of the prothorax; but the head is much 

 shorter and the fore legs are enormously developed 

 for grasping, this series being also predatory in the 



adult stage. But the interest- 

 ing feature is that we find in 

 the larva the first tendency 

 toward parasitism and the 

 specializations accompanying 

 it. The eggs are laid on stalks 

 like those of the Aphis-lions, 

 but the resulting young live 

 for months without food, until 

 FIG 37. Mantispa species t h e egg sacs of certain Lycosid 



from above and in outline from 



side. spiders have been formed. 



The lucky larva that finds 



such a sac bites its way through the covering and feeds 

 upon the contents. As it feeds and grows it loses its 

 large head and long legs, and becomes helpless except 

 to feed upon the surrounding material which serves 

 to bring it to maturity. While in a general way these 

 insects are said to be parasitic in the egg sacs of spiders 

 yet this is not really a true parasitism at all; it is 

 simply a feeding upon the eggs and young spiders as 

 any predatory species might feed upon them, the only 

 difference being that here the larva makes itself at 

 home and does its feeding gradually, so as to secure 

 enough to reach maturity. 



The order Mecoptera is a curious one, only a few 



