Field Tests with Kairomone–Baited Traps for Cucumber Beetles and Corn Rootworms in Cucurbits

Abstract

Sticky traps with and without the attractant TIC (1,2,4-trimethoxybenzene, indole, and tralls-cinnamaldehyde) were evaluated in cucurbits for capture of striped cucumber beetle, Acalymma trivittaum (F.), spotted cucumber beetle, Diabrotica undecimpunctata howardi Barber, western corn rootworm, Diabrotica virgifera virgifera LeConte, and northern corn rootworm, D. barberi Smith & Lawrence, in New York and western striped cucumber beetle, Acalymma trivittatum (Mannerheim), and western spotted cucumber beetle, Diabrotica undecimpunctata undecimpunctata Mannerheim, in California. Traps with TIC lures captured more beetles than un baited traps for all species except for western spotted cucumber beetle in 1 of 2 California trials. Yellow traps captured more striped cucumber beetle and western spotted cucumber beetle than did white traps but did not increase capture of spotted cucumber beetle or western striped cucumber beetle. The response of the western corn rootworm and northern corn rootworm to TIC varied by time of day, the greatest response occurring around midday. Increases in TIC per trap resulted in increases in capture of western spotted cucumber beetle, western striped cucumber beetle, western com rootworm, and striped cucumber beetle, but not for northern corn rootworm or spotted cucumber beetle. For cucurbits with short plant canopies, traps were most effective when placed close to the ground. In pumpkins with taller canopies, traps at canopy and midcanopy height captured the most beetles. The effect of trap height varied by time of day for spotted cucumber beetle, western corn rootworm, and northern corn rootworm, and the pattern varied for the species. Sex ratio of captured beetles varied among species and time of day. Overall, western corn rootworm and northern corn rootworm were captured in greatest numbers during the middle of the day, whereas the greatest captures of striped cucumber beetle occurred between 1800 and 0600 hours EST. Significantly greater numbers of striped cucumber beetle, western corn rootworm, and northern corn rootworm were captured on the downwind side of traps. Traps replaced 2 times per day had greater captures than traps replaced 1 time per day or 1 time every 2 d.