BULLETIN 39, UNITED STATES NATIONAL MUSEUM. 



[24] 



prismg, 

 insects 



be d 



-Lace-wing fly. a, eggs, &, larva, c, cocoons, d, fly 

 with left wings removed. 



(^S-^s, 



Fig. 37.— An Ant-lion (Myrmeleon). (From Packard.) 



of our largest aiidmost striking insects, the larvne of wliich is known as 

 Dobsons by anglers, and is aquatic and carnivorous in habit. The Heme- 



robiidi© is a large family, com- 

 as a rule, delicate 

 with rather ample 

 gauzy wings. The larvee are 

 predaceous. The common 

 Lace- wing flies are among our 

 most beneficial insects, de- 

 stroying plant-lice and other 

 soft-bodied species. To the 

 same family belongs the Ant-lion {Myrmeleon), the larvse of which have 

 the curious habit of constructing 

 a funnel-shaped burrow in the 

 sand, in the bottom of which they 

 conceal themselves and wait for 

 any soft-bodied insects which 

 may fall into the trap. This fam- 

 ily also includes the 

 peculiar Mantis-like in- 

 sects belonging to the 



genus Mantispa. As in the true Mantis, the prothorax of 

 these insects is greatly elongated and the first pair of legs 

 are fitted for grasping. The larvse 

 are parasitic in the egg-sacs of cer- 

 tain large spiders (genera Lieosa, 

 DolomedeSy etc.), and undergo a remarkable 

 change in form after the first molt. In the 

 first stage the larvae are very agile, with slen- 

 der bodies and long legs. After molting the 

 body becomes much swollen and the legs are 

 much shortened, as are also the antennae, the 

 head becoming small and the general appearance reminding one of the 

 larva of a bee. 



The second section of the Neuroptera, characterized by complete 

 metamorphosis, comiDrises the following suborders : 



Suborder Platyptera {-Xaroq, flat; Ttrepu'^^wmg). Under this nead 

 are grouped the White-ants {Termitidce), the Bivd-hce f2IallopJiaga J,. 

 and the Book-mites {Psocidw). The suborder receives its name from 

 the fact that in the case of the winged forms the wings, when at rest, 

 are usually laid flat upon the back of the insect. The Mallophaga, or 

 Bird-lice, are degraded wingless insects, and are parasitic chiefly on 

 birds, but also on mammals. In shape of body and character of the 

 mouth-parts they are most nearly allied to the Psocida?. The latter 

 family includes both winged and wingless forms, the Book-mites be- 

 longing to the latter category. The winged forms may be illustrated 



Fig. S9.—Mantispa with side 

 view beneath. (From Packard.) 



