Study on the Spatial Pattern of Eggs and Larva-web of Fall Webworm
- Received Date: 2003-04-14
Abstract: In areas where Hyphantria cunea (Lepidoptera: Arctiidae) were a serious pest to host trees, the spatial pattern of the pest’s egg cluster and the larva-web were studied in forest land and on shelter-wood trees. It was revealed that the spatial pattern of the egg clusters and larva-webs of the fall webworm belonged to Negative Binomial Distribution, which was also a kind of Aggregated Distribution. Meanwhile, Aggregated Degree Index of egg clusters and larva-webs were also studied and the results showed that the spatial patterns of fall webworm were Aggregated Distribution. Based on these studies,the theoretical sampling numbers of different density of egg clusters and larva-webs in two different kinds of forest stands were calculated too, and that will give a approximately quantity information of the fall webworm for the decision of releasing number of insect natural enemies.