Studies on the ecology of Oncopera intricata Walker (Lepidoptera: Hepialidae). 2. Selection of oviposition sites by the female moths.

Abstract

The results are reported of studies on the effect of length and density of pasture cover on the selection of oviposition sites by the mated female moths of Oncopera intricata Walker. Moths were placed in a wire-mesh cage, 7 ft in diameter and 2 ft high, in which they were given a choice of pasture cover in which to oviposit. It was found that the length of the grass cover was important in causing settling by the moths since when only short cover was provided, few moths laid their eggs in the plots irrespective of the density of the cover provided. When long cover was provided in some of the plots the preferred sites were where the cover was long and dense but a reasonable number of moths oviposited in short sparse cover. Where long cover alone was provided the dense plots were preferred to the sparse. The implications of these results on the pattern of distribution and survival in natural populations is discussed.