Insects in Illinois.
Prof. Forbes, State Entomologist, makes the following report to the State Board of Agriculture:
"Now that our year's entomological campaign is completed, a brief review of some of its most important features and results will doubtless be of interest. Early attention was given to the insects attacking corn in the ground, before the sprout has appeared above the surface. A surprising number were found to infest it at this period, the results of their injuries being usually attributed by farmers to the weather, defective seed, etc. Among these the seed corn maggot (Anthomyia zeæ) was frequently noted, and was received from many parts of the State. A small, black-headed maggot, the larva of a very abundant, gnat-like fly (Seiara), was excessively common in ground which had been previously in grass, and attacked the seed corn if it did not germinate promptly and vigorously, but apparently did not injure perfectly sound and healthy grains. A minute yellow ant (Solenopsis fugax) was seen actually gnawing and licking away the substance of the sound kernels in the ground, both before and after they had sprouted. The corn plant-louse (Aphis maidis) was an early and destructive enemy of the crop, often throttling the young shoot before it had broken ground. It was chiefly confined to fields which had been just previously in corn or grass.
"The chinch-bug was found in spring depositing the eggs for its first brood of young about the roots of the corn, a habit not hitherto reported.
"With the increasing attention to the culture of sorghum, its insect enemies are coming rapidly to the front. Four species of plant-lice, two of them new, made a vigorous attack upon this crop in the vicinity of Champaign, and two of them were likewise abundant in broom-corn.
"The corn root-worm (Diabrotica longicornis) was occasionally met with in sorghum, but does not seem likely to do any great mischief to that plant. It could not be found in broom-corn. In fields of maize, however, it was again very destructive, where corn had been raised on the same ground a year or two before. The Hessian Fly did great damage throughout the winter wheat region of the State, many fields not being worth harvesting in consequence of its ravages. Several facts were collected tending to show that it is three brooded in the southern part of the State. Nearly or quite all the last brood passed the summer as "flax seeds" in the stubble, where they might easily have been destroyed by general and concerted action. Fortunately, the summer weather was unfavorable to their development; and the drouth conspired with their parasites to greatly diminish their numbers. In the regions under our observation, not one in a thousand emerged from the midsummer pupa-cases, and numbers of the larvæ were found completely dried up.
"The wheat straw-worm (Isosoma tritici), a minute, slender, yellow grub, which burrows inside the growing stem, dwarfing or blighting the forming head, was abundant throughout the winter wheat region of Southern Illinois, causing, in some places, a loss scarcely exceeded by that due to the Hessian Fly. Our breeding experiments demonstrate that this insect winters in the straw as larvæ or pupa, emerging as an adult fly early in spring, these flies laying their eggs upon the stems after they commence to joint. As the flies are very minute, and nearly all are wingless, their spread from field to field is slow, and it seems entirely within the power of the individual farmer to control this insect by burning or otherwise destroying the stubble in summer or autumn, and burning the surplus of the straw not fed to stock early in spring. A simple rotation of crops, devoting land previously in wheat to some other grain or to grass, will answer instead of burning the stubble.
"The life history of the wheat bulb-worm (Meromyza Americana) was completed this year. The second or summer brood did decided injury to wheat in Fulton county, so many of the heads being killed that some of the fields looked gray at a little distance. This species was also injurious to rye, but much less so than to wheat. It certainly does not attack oats at all; fields of that grain raised where winter wheat had been destroyed by it, and plowed up, being entirely free from it, while wheat fields adjacent were badly damaged. We have good evidence that postponement of sowing to as late a date as possible prevents the ravages of this insect, in the same way as it does those of the Hessian Fly.