HEMEROBID^. 



611 



in form. The partially active pupoe crawled out of the co- 

 coons, and were found scattered about in the paper containing 

 them. 



The genus Polystoechotes is of much larger size than Heme- 

 robius or Chrysopa, and Hagen suggests that the larva is 

 aquatic. P. piaictatus Fabr. is widely distributed, 

 flying lazily at night-fall. The aberrant genus Man- 

 tispa is a most interesting form, from the great length 

 of the prothorax, which with other characters remind 

 us strikingly of the Orthopterous genus Mantis. The 

 fore legs are, like those of Mantis, adapted for seizing 

 other insects. Mantispa hninnea Say is our most 

 common species, occurring in the Middle and Western 

 States and southwards to Central America. 



Chrysopa (Fig. 601, eggs, larva, and adult of C. 

 perla of Europe), the Lace-winged 

 Fly, is abundant and of great use, as 

 in the larva state it preys on plant- 

 lice. Its body is slender, with deli- F'^- ^'^^• 

 cate gauze like wings, and is generally green, 

 with golden eyes. When disturbed it often 

 emits a foetid odor. Their eggs, supported by 

 long pedicels, are often laid in a group of 

 Aphides or in plants infested by them. When 

 hatched the voracious larva finds its food 

 ready at hand, and destroys immense numbers 

 of plant-lice, whence its name, Aphis-lion. It 

 turns to a pupa late in summer, and thus passes the winter 

 within a very dense, round, whitish cocoon situated 

 in the crevices of bark, etc. 



In Europe gardeners search for these Aphis-lions 

 and place them on fruit trees overrun with lice, 

 which they soon depopulate. The Chrysopa ocn- 

 lata of Say (Fig. 602, and eggs) is our most abun- 

 dant form. It gives out a foul smell when handled. 

 By this genus we are led to the Ant-lion, or Myrme- 

 leon. It is a larger insect than any of the fore- 

 going genera, and reminds us in many respects of the dragon- 

 flies. The antennae are short and stout, clavate, while the body 



Fiff. 599. 



Fig. 600. 



