An alternative sampling technique for cucumber beetles (Coleoptera: Chrysomelidae) and diurnal beetle activity on...

Field studies were conducted to investigate the effectiveness of yellow sticky traps as an alternative sampling technique for striped, Acalymma vittatum (F.), and spotted, Diabrotica undecimpunctata howardi Barber, cucumber beetles (Coleoptera: Chrysomelidae) and the diurnal beetle activity on muskmelon, Cucumis melo L., near Vincennes, IN, in 2003 and 2004. The experimental design included six replications of seven 20-m-long rows each of muskmelon with 1.5 m between rows. On each sampling date, two yellow sticky traps were placed randomly between rows in each replication. One sticky trap was placed vertically with the lower edge even with the top of the canopy, whereas the other trap was placed horizontally, even with the top of the canopy. After traps were placed in the field, number of beetles on plants was counted in situ from 0800 to 1600 hours at 2-h intervals the next day. After 48 h in the field, the number of cucumber beetles adhering on traps was counted. Analyses of variance and Tukey's multiple comparison procedure were used to compare the densities of beetles among sampling times, and regression analyses were applied to correlate the numbers of beetles on traps and the numbers of in situ counts. Results show that both species of cucumber beetles were most active from 1200 to 1400 hours, and 20 beetles on the vertically positioned sticky trap were equivalent to one beetle per plant in the field. The application of the sampling technique and scouting time for cucumber beetle management are discussed.