HOW TO KNOW THE INSEaS 



Fig. 175. 

 L. 



Corydalls cornuta 



Brown, the sexes differ In 

 that the male has long man- 

 dibles and the female short 

 ones. They are found flying 

 near streamiS and attract miuch 

 attention. Vifing expanse 

 100-130 mm. 



This family contains the 

 Figure 175. largest members of the Neur- 



optera. The larvae are 

 aquatic, and the adults 

 ordinarily do not pet far from water. The alder flies are com- 

 paratively small, soft winged and often smoke colored. 



2b Hind wings narrow at base, not folded 3 



3a Less than one inch in length; antennae not enlarged at tip. 

 CThe Lacewing Flies or Aphis-Lions) See Fig. 52. 



Family 9, CHRYSOPIDAE 



These fragile insects are exceedingly valuable in that their 

 larvae have an insatiable appetite for plant lice. The eggs are 

 white and placed at the top of a stiff bristle about a quarter of 

 and inch long. This is thought to be done to prevent the first 

 larva that hatches from eating the other eggs. The cocoon is 

 spherical, about the size of a B.B. shot. How a creature the 

 size and shape of the adult could come from it seems a mystery. 

 The genus has several Iowa species but all look very much alike. 



3b Over one inch in length; antennae usually knobbed at end. . 4 

 4a Antennae long. Insects resembling dragon flies except for 

 antennae. (The Ascalaphids) Fig. 176. Family 11, ASCALAPHIDAE 



Fig. 176. Ulo lodes made ay ana hageni 

 Van der Weele. 



Reddish brov.m. Long lighter browri 

 hairs on front of head and sides of 

 thorax. Wings hyaline. Stigma near 

 apex of v/ings, yellowish white. Ex- 

 panse of wings about 65 mm. 



If it had not been a rather inno- 

 cent little girl who brought in my 

 first specimen of this family I 

 would have been sure it had been 

 made by gluing parts of different 

 insects together. The Ascalaphids 

 are so uncommon that we wish to get 

 the record on any that are found in 

 the state. The adults prey on 

 other insects. 

 4b Antennae short. Feeble flying insects, resembling damsel 

 flies. (The Ant Lions) Fig. 177. 



Family 10, MYRMELEONI DAE 



Figure 176, 



