Transcontinental Crashes of Insect Populations?

1. Department of Ecology and Evolutionary Biology, University factors that may be operating within the populations. Beof California, Irvine, California 92697 cause our focus was on the drought, we also obtained 2. Department of Entomology, University of California, Davis, records of annual precipitation for the regions where California 95616-8584 each insect population occurs for the period 1978–1996. We located time-series data for 10 insect taxa, repreSubmitted December 4, 1997; Accepted March 17, 1998 senting a wide range of life histories, habitats, and geographic regions in North America (references in fig. 1 legend): gypsy moth (Lymantria dispar, Lepidoptera: Lymantriidae) in Massachusetts; a multispecies complex of