As part of the process of developing sampling programs for the Obliquebanded leafroller, Choristoneura rosaceana, and Pandemis leafroller, Pandemis pyrusana, in apples, we examined the spatial autocorrelation of larval samples spaced uniformly throughout several apple blocks during the overwintering, summer, and fall generations. Variograms showed that spatial dependence in any generation was virtually non-existent when leafroller population levels were high, but noticeable on a small scale when population levels were low. At low population levels, anisotropic variograms showed that spatial autocorrelation was significantly greater within a row than between rows, and population clumps were approximately 30 feet in diameter. The development of sampling plans that deals with the spatial distribution of the two leafroller species is discussed.
Species 1: Lepidoptera Tortricidae Pandemis pyrusana (Pandemis leafroller)
Species 2: Lepidoptera Tortricidae Choristoneura rosaceana (obliquebanded leafroller)
Keywords: spatial distribution, geostatistics
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA