Nerve-winged Insects; Scorpion-flies; Caddis-flies 235 



Mantispa larvae find them out, tear a hole in the bag, and enter among the 

 eggs ; here they wait until the eggs have attained a fitting stage of develop- 

 ment before they commence to feed. Brauer found that they ate the spiders 

 when these were quite young, and then changed their skin for the second 

 time, the first moult having taken place when they were hatched from the 

 egg. At this second moult the larva undergoes a considerable change of 

 form; it becomes unfit for locomotion, and the head loses the compara- 

 tively large size and high development it previously possessed. The 

 Mantispa larva only one of which flourishes in one egg-bag of a spider 

 undergoes this change in the midst of a mass of dead young spiders it has 

 gathered together in a peculiar manner. It undergoes no further change 

 of skin, and is full-fed in a few days; after which it spins a cocoon in the 

 interior of the egg-bag of the spider, and changes to a nymph inside its larva- 

 skin. Finally the nymph breaks through the barriers larva-skin, cocoon, 

 and egg-bag of the spider by which it is enclosed, and after creeping about 

 for a little appears in its final form as a perfect Mantispa." 



Thus in this insect the larval life consists of two different stages, one 

 of which is specially adapted for obtaining access to the creature it is to 

 prey on. 



The Coniopterygidae include a few tiny, obscure insects, the smallest 

 members of the order. They have wings with very few cross-veins, and 

 both wings and body are covered with a fine whitish powder, hence the name 

 "dusty wings" which entomologists apply to them. Only two species are 

 known in this country, of neither of which is the life-history known. In 

 Europe the larva? of a "dusty wing" species have been found feeding on 

 scale-insects. When full-fed these larvae spin a silken cocoon, within which 

 they transform. 



THE SMALL and little-known order Mecoptera includes certain strange 

 little wingless, shining black, leaping insects found on snow, some larger 

 net-veined-winged insects with the abdomen of the males ending in a swollen 

 curved tip bearing a projecting clasping-organ resembling slightly a scor- 

 pion's sting in miniature, and a number of still larger, slender-bodied, narrow- 

 winged insects. The only popular name possessed by any of these insects 

 is that of scorpion-flies, which has been given the few species with pseudo- 

 stings. For these scorpion-flies are not stinging-insects, although the males 

 can pinch hard with the caudal clasping-organ. But little is known of the 

 life-history of any members of the order, nor is much known of the habits 

 of the imagoes. 



There are but five genera in the order, which may be distinguished by 

 the following key: 



