36 INJURIOUS INSECTS OF KANSAS. 



Description and Life-history. — The adult insect is a very small, 

 four-winged insect (most of the specimens are wingless), black, with 

 green and blue metallic reflections. The damage to the wheat is 

 done by the insect in its larval stage, when it appears as a small, 

 white grub, less than one-fourth of an inch long, which lies in the 

 heart of the stem near a joint. The grubs are provided with 

 strong jaws, with which they gnaw the inner fiber of the stem, 

 arresting a proper flow of the sap to the head. In March and 

 April adults issue from last year's wheat straws (in the stack or 

 in the stubble), and lay their eggs on the tender leaves of the 

 growing wheat. The larvae, on hatching, burrow into the stem, 

 pupate, and soon mature, the adults emerging in the latter part 

 of May and early part of June. These adults lay their eggs in 

 the now ripening wheat, and another brood of destructive larvae 

 hatches. These larvse pupate in the straws, either in stubble or 

 stack, before winter, and pass the winter in the pupal stage. The 

 following spring the adults appear, and a new cycle is begun. The 

 insect is thus two-brooded. 



Remedies. — The plainly-suggested remedy is to destroy the in- 

 sect while hibernating in the pupal stage in the old straw. The 

 stubble and all remnants of straw-stacks should be burned before 

 March 1 ; that is, before the issuing of the adults in the spring. 

 Whether the insect is present in the straw can be easily told dur- 

 ing the winter, or by splitting open straws and examining. The 

 pupse, if present, will be found as small, dark, mummy-like ob- 

 jects, about one-fifth of an inch long, resting securely in small 

 cells hollowed out in the center of the straw near a joint. As 

 only about five out of every 100 individuals of this insect pos- 

 sess wings, the insect spreads very slowly from farm to farm, and, 

 if all the hibernating individuals on a given farm be destroyed, 

 there is no likelihood that the wheat on that farm can be attacked 

 the following season. 



This pest also suffers from the attacks of several parasitic in- 

 sects, one of the most important of which, Eupelmus allyni, is a 

 small, four-winged insect, which belongs to the same family as the 

 pest itself. This Eupelmus parasite lays its eggs in the spring, 

 after the Straw-worm larvse have hatched, and the larvse of the 

 parasite, as soon as hatched, feed on the Straw-worm larvse. By 

 the middle of September the parasites have matured and escaped 

 from the straws. Thus, the burning of the old straw in the win- 



