ENTOMOLOGY 191 



between the leaves to the crown of the plant and feed on the central 

 part of the stem, cutting it entirely off and causing the central blade 

 to discolor and die. These maggots pass the winter in the wheat, at 

 the point indicated, and transform to pupae in April and May and 

 emerge as adults in June. An adult is about one-fifth of an inch 

 long, greenish in color, and marked with three longitudinal black 

 stripes on the back (thorax and abdomen). The eggs of this brood 

 of flies are deposited, often several in a row, usually near the edge of 

 the sheath of the upper leaf, so that the larvae or maggots coming 

 from them can readily penetrate the succulent portion of the stem 

 just above the last joint, where they remain feeding on the stem and 

 eventually killing it, causing the upper portion of the straw to wither 

 and die and the head to blight or turn white. The second brood of 

 adults escapes from the straw in July and August and breeds in vol- 

 unteer wheat or various grasses, developing a third brood of adults 

 in time to infest the winter wheat in September and October. 



The chief remedy for the Hessian fly, namely, planting of 

 wheat, does not, unfortunately apply to this closely allied pest, be- 

 cause the adult females of the latter are known to occur abundantly 

 up to October. If grain can be thrashed promptly after harvest and 

 the straw and stubble burned, it will doubtless effect the destruction 

 of a great many of these pests, or if the grain be removed from the 

 field as soon as practicable after being harvested most of the insects 

 will be carried away and will not succeed in escaping from the center 

 of the stacks at least. Rotation of crops as a preventive applies also 

 to this insect, but even this remedy loses some of its value from the 

 fact that the species breeds in various grasses. Fortunately, some 

 important parasitic and predaceous insects usually keep this grain 

 pest in check, and it is therefore unusual for it to assume a very in- 

 jurious role, although widespread and frequently occasioning more 

 or less loss. 



The Army Worm. Damage to wheat from the caterpillars com- 

 monly known as army worms and the injury caused by the allied 

 cutworms, which come in the same category, are of such an inter- 

 mittent or occasional character that the farmer can hardly be ex- 

 pected to take regular precautions to prevent the attacks of these 

 insects. Severe injury is witnessed, as a rule, only at comparatively 

 long intervals at a time in any one region, although injury probably 

 occurs every year in some part of the country or other in varying 

 amount. Where farms are carefully and cleanly cultivated, and not 

 contiguous to waste or swampy land, and ground to be planted in 

 wheat is early plowed, damage from these pests will not often be 

 experienced. The more serious army worm outbreaks are most 

 common in the months of May and June, or sometimes as late as 

 July, when wheat, oats, and other small grains, corn, timothy, and 

 various grasses, with the exception of clover, are occasionally sud- 

 denly overrun by multitudes of the dark-co-lored, naked, striped cat- 

 erpillars of this insect. These hordes of larva? usually travel in ono 

 direction, passing from one field to another, destroying crops as they 

 go. They have a habit, also, of climbing the stalks of such grasses 



