Effect of Ovulation Upon Seasonal History in the Alfalfa Weevil

Abstract

Larvae of the alfalfa weevil, Phytonomus posticus, occur sparingly throughout the summer after the greater number have become adults. They are too few to injure the third and fourth crops, upon which they occur, but they raise the question whether they belong to a second generation which might, under other climatic conditions, become injurious. To determine this point it was necessary to collect, dissect, and examine the reproductive organs of hundreds of female beetles of all ages. From the history of ovulation thus established, it is evident that the few surviving old beetles produce the late summer eggs and larvae.