ATTRACTANTS FOR ADULT SOUTHERN CORN-ROOTWORM (COLEOPTERA, CHRYSOMELIDAE) MONITORING IN PEANUT FIELDS AND RELATIONSHIP OF TRAP CATCH TO POD DAMAGE

Field studies were conducted in 12 locations in southeastern Virginia to evaluate 3 trap attractants, 1,2,4-trimethoxybenzene, indole and tr ans-cinnamaldehyde (TIG), trans-cinnamaldehyde, alone, and sex pheromo ne (10-methyl-2-tridecanone), for monitoring adult southern corn rootw orm, Diabrotica undecimpunctata howardi Barber, phenology in peanut, A rachis hypogaea L.; and to determine the relationship of trap catch to peanut pod damage as it occurred throughout the season. Pheromone tra ps caught more beetles than TIC or cinnamaldehyde on most sample dates and at most locations. Pheromone traps detected 2 distinct beetle pea ks, the Ist between 1 and 23 June, and the 2nd between 21 and. 28 July , and consistently caught more males than females. TIC and cinnamaldeh yde traps caught more females in 14 out of 180 observations (15 sample dates, 12 locations) and failed to detect the 2nd beetle peak. Peanut pod damage began to increase in all locations at the end of July. Tot al pod damage (immature plus mature pods) exceeded 40% in all but one location. Peak damage occurred at all but 1 location on approximate to 11 August. Peak pod damage by southern corn rootworm larvae consisten tly lagged behind the 2nd peak in the beetle population by 2.1 +/- 0.5 (+/-SEM) wk. Number of beetles trapped accounted for only 10% of the variance observed in peak pod damage. Use of pheromone traps by grower s could allow fbr a more precise timing of insecticide applications an d improve management of southern corn rootworm in peanut.