Note on Destruction of Grasshopper Eggs by the Field Cricket Acheta assimilis luctuosus (Serville) (Orthoptera: Gryllidae)

Abstract

Routine grasshopper egg surveys in southern Alberta from 1954 to 1957 revealed unexpectedly small numbers of egg pods in certain locations that were regarded as favoured oviposition sites for Mlelnnoplus bivittatus (Say). These locations were graded roadsides with a bare or sparsely covered slope on the field side of the ditch. The bottom of the ditch and the other slope up to the roadway were usually covered with a moderate to heavy growth of weeds and grass. In these years the grasshoppers hatched late, the nymphs developed slowly, and the adults did not mature until September. As oviposition took place in cool fall weather,it was restricted mainly to the bare ditchbanks facing south or west, which provided sheltered spots warmed by insolation. Sampling in these spots revealed fewer egg pods than should have been produced by the number of M. bivittatus found in the preceding adult survey.