PREDACEOUS ENEMIES. 



133 



plant-lice or other insects are impaled and held prisoners until they 



are sucked dry. They are then released and the Chrysopa larvae 



hunt other victims. 



C ecidomyiidse . 



During September of 1909, at Lafayette, Ind., a new predaceous 

 insect enemy to Toxoptera was discovered in the larvse of a little 

 cecidomyiid or two-winged fly, determined tentatively for us as 

 Apliidoletes sp. by Dr. E. P. Felt. It was first observed in one of the 

 stock cages and afterwards it was found to be reproducing in the fields 

 on Myzus persicse. 



Fig. 46.— The golden-eyed lace-wing fly ( Chrysopa oculata), an enemy of the spring grain-aphis, a, Eggs; 

 b, full-grown larva; c, foot of same; d, larva devouring an insect; e, cocoon; /, adult insect; g, head of 

 same; h, adult, natural size. All enlarged except h. (From Marlatt.) 



We have not as yet carefully studied the life history of Apliidoletes 

 sp. The adult fly (fig. 47) is a frail little creature, about the size of 

 the clover-seed midge, pale cream in color, and the abdomen has a 

 pinkish tinge, due to the pink eggs within. The eggs resemble 

 those of the Hessian fly very closely except that they are much 

 smaller. The larvae (fig. 48), which are pinkish in color, descend to 

 the ground when fully matured, and at or near the surface they spin a 

 loose cocoon, to which particles of dirt and trash adhere. In a few days 

 the adults issue. The time required for this little insect to complete 

 the entire life cycle is apparently about 10 to 14 days. The species 

 is not determinable further than the genus for the reason that only 

 the female adults have been secured. 



