USDA ASKS TIGHT INSECT RULES FOR GRAIN SHIPMENTS The U.S. Agriculture Department is proposing tighter federal standards setting allowable limits on insect infestations in grain shipments. The changes in the standards would include the following: -- Establishing equal tolerances for the number of live insects in shipments of food grains, feed grains and oilseeds. -- Revising the definition of "infested" to give equal value to all insects injurious to grain. -- Establishing lower levels of infestations. In 1988, the infested level would be set at three or more live insects per representative sample (about 100 grams), in 1990 two or more insects, and in 1992 the final infestattion level would be set at one or more live insects per representative sample. -- Revising the definition of sample grade by adding a limit of 10 live or dead insects per sample. -- Revising the definition of sample grade for wheat by adding a limit of 32 insect-damaged kernels per 100 grams of wheat. The department asked for public comments on the proposals by April 17.