STORED-GRAIN INSECTS
INTRODUCTION
Since the establishment of Federal standards for grain under the pro-visions of the Grain Standards Act, Federal grain supervisors and federally licensed grain inspectors have been required to identify the various species of “live weevils and other insects injurious to stored grain” which may be present in the grain. For accurate identification, uniform names should be used by all interested persons, including shipper, purchaser, and elevator operator.
Of the five primary insect pests, the granary weevil, the rice weevil, the maize weevil, and the lesser grain borer may well be called grain weevils. The fifth primary pest, the Angoumois grain moth, so destructive to wheat and corn, may be called a grain moth. Other insects likely to be found in grain may be called simply beetles, moths, and meal-worms. Their presence usually does not indicate a condition likely to affect the grain trade, if the grain, after it has reached the elevator, is screened and fanned to remove these insects.
This handbook briefly describes the biology, life histories, and habits of stored-grain insects and gives effective methods for the prevention and control of grain infestations.
Grain weevils, grain borers, grain moths, flour moths, grain and flour beetles, mealworms, dermestid beetles, spider beetles, miscellaneous beetles, booklice or psocids, silverfish, cockroaches, flour or grain mites, and parasites of grain pests are discussed.
GRAIN WEEVILS
Of the five true weevils that attack grain in the United States, only three are of primary importance—the granary weevil, the rice weevil, and the maize weevil. Except locally, the broadnosed grain weevil and the coffee bean weevil are of minor importance. All but the coffee bean weevil have elongated beaks or snouts, as shown in figures 1, 3, and 4.
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