Monday, December 11, 2006 - 9:35 AM

Seasonal phenology, natural enemies, and control of the squash bug, Anasa tristis (DeGeer), on summer squash in Kentucky

Kimberly Decker, and Kenneth Yeargan, University of Kentucky, Department of Entomology, S-225 Agric. Sci. Bldg. North, Lexington, KY

The squash bug, Anasa tristis (DeGeer), is a major indigenous pest of Cucurbita species across the United States and vector of Curcurbit Yellow Vine Decline. The seasonal phenology of the squash bug in Kentucky and its natural enemies were studied using continuously planted yellow summer squash throughout the growing season. The squash bug was first detected on 5 June 2005 and 3 June 2006. In both years, peak numbers of all squash bug stages occurred in late July and early August with a lesser peak in late September, indicating that the squash bug may have one complete generation and a partial second generation in Kentucky. Squash bug egg masses were monitored to determine predation and parasitism rates in the field. In four studies during 2005 and 2006, predation rates were low (7% or less) and parasitism ranged from 0 to 31%. Direct observations of predation included Geocoris punctipes (Say), Nabis sp. and Pagasa sp. All parasitism was by Gryon pennsylvanicum (Ashmead). Control methods for squash bugs were studied in June- and August-planted squash fields in 2006 with treatments consisting of floating row covers, Beauveria bassiana strain ATCC 74040, an insecticide regime consisting of thiamethoxam and permethrin and an untreated control. Weekly squash bug counts revealed a reduction in numbers by the insecticide regime with little difference among other treatments. The insecticide regime also had the highest yield of harvestable squash over a two-week harvest period.

Species 1: Hemiptera Coreidae Anasa tristis (squash bug)

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