ENEMIES OF WHEAP XOi 



insar* \s mild weather fnr four to six weeks after the wheat is planted. The spring 

 brood reaches the adult stage during the latter part of April, during May and the 

 first part of June. 



The adult lays an oval-shaped egg, reddish in color, one-fiftieth of an inch long, 

 on the inner side of the leaf blade. The egg hatches in a few days into a pinkish 

 larva, soon changing to greenish, which finds its way do\\Ta to the base of the leaf 

 sheath. As the eggs in the fall are usually laid upon the youngest plants, the larvae 

 are to be found somewhat under the ground, where they kill the diminutive culm. 

 In this case the plant vill be killed unless it has tillered, and some of the tillered 

 culms escape. In the spring the eggs are laid on leaves somewhat higher up and 

 the larvae will be found at the base of the first two or three leaves above the ground, 

 where the injury causes many of the culms to fall before the grain is ripe. The 

 puparium of the insect resembles in form and color a flaxseed. The pupal stage is 

 therefore called the " flaxseed stage." When two-brooded, this insect passes the 

 winter and the summer in the flaxseed stage. 



Preventive measures are (i) late sowing, preferably delayed until after sharp 

 frosts ; (2) rotation of crops ; (3) burning stubble ; (4) so^^■ing strips of wheat early 

 as baits to be plowed under as soon as eggs have been laid. Of these the first two 

 are to be especially recommended. The Hessian fly has many parasitic insects, 

 otherwise it would probably make the raising of wheat impossible. Burning the 

 stubble will destroy the parasites as well as the Hessian fly, which may not alus-ays 

 be adWsable, The destruction of organic matter also usually will not be desirable. 

 In order to get the best results from late sowing it is advisable for farmers to act 

 together, else the spring brood from the early sown wheat may attack the field which 

 has escaped the fall brood. 



There are no Hessian fly proof varieties of wheat, although those varieties which 

 tiller most freely and have the stiffest and hardest culms will doubtless resist their 

 attacks the best. 



153. The Wheat Bulb-worm. — The wheat bulb-worm is a two-\N-inged fly 

 with essentially the same habits as the Hessian fly, except that it lives upon oats as 

 well as seA'eral grasses, including timothy. The injur}- from the fall brood is almost 

 identical with that of the Hessian fly ; while the spring brood lays its eggs usually 

 upon the upper leaf, thus causing the culm to v.-ither and die above the upper node. 

 While the Hessian fly therefore usually remains in the stubble after harvest, the 

 wheat bulb-worm is carried from the field with the straw. The damage done by this 

 insect is much less than that of the Hessian fly, for which it is doubtless frequently 

 mistaken. 



154. The WHE.A.T Midge. — The wheat midge is also a two-winged insect. 

 About the time the wheat is in the flower, the adult lays its eggs singly or in 

 clusters to the number of ten upon the glumes of the wheat spike. The larvae 

 suck the milky juice from the young grains, causing them to shriveL Thev 

 impart their orange-yellow color to the blighted spike. The insect is probably third 

 in the injury to the wheat plant, but unlike the chinch bug and the Hessian fiy, 

 it thrives best in moist weather. The larvae enter the ground after about three 

 weeks and pass the %\-inter in the pupal stage. Many, however, are still in the 



