Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/15/2005
Publication Date: 10/1/2005
Citation: Knight, A.L., Light, D.M. 2005. Factors affecting the differential capture of male and female codling moth (Lepidoptera: Tortricidae) in traps baited with ethyl (E,Z)-2,4-Decadienoate. Environmental Entomology. 34(5):1161-1169. Interpretive Summary: There is a need to monitor codling moths in apple and pear orchards to determine the necessity of control measures. A difficulty in monitoring with attractants in traps is correlating the catch of female moths with the potential for fruit injury within orchards. Thus researchers at the USDA-ARS Yakima Agricultural Research Laboratory conducted studies to evaluate how a number of factors may influence catches of both sexes of codling moth. It was found that a number of factors differentially affect the capture of male and female codling moths in pear ester-baited traps including trap height and size and the proximity of foliage and fruit to the trap. In addition, the application of sex pheromone dispensers for mating disruption increased the proportion of trapped moths that were female. These data will be useful in standardizing the use of pear ester-baited traps by pest managers to monitor codling moth. In addition, the consideration of factors that can enhance the capture of female moths will improve the performance of lure and kill strategies for codling moth.
Technical Abstract: Studies were conducted in apple to evaluate factors that differentially affect the catch of male and female codling moth, Cydia pomonella (L.), in traps baited with ethyl (E, Z)-2,4-decadienoate (pear ester). We examined the time of moth capture in the diel cycle and the recapture rates of marked moths in sex pheromone mating disruption (MD) and untreated orchards. The attractiveness of pear ester-baited traps was compared among five apple cultivars. Experiments also were conducted to assess the influence of trap height, the distance of the trap from sex pheromone dispensers, proximity of foliage surrounding the trap, trap size, and proximity of adjacent clean and codling moth-injured fruit on moth captures. Peak male capture using pear ester lures coincided with male catch in codlemone-baited traps; while, peak female capture occurred earlier. A higher proportion of recaptured, marked moths were females in MD versus untreated orchard plots in pear ester-baited traps. Significantly higher counts of male and female moths were trapped in blocks of 'Granny Smith' versus four other cultivars. Recapture rates of marked moths were not different at release points ranging from 10 ' 50 m for either sex. Traps baited with pear ester placed 15 or 100 cm from MD dispensers (Isomate-C PLUS) caught a similar number of male and female moths. Significantly more male but not female moths were caught in traps placed high versus low in the tree canopy. Traps placed on the perimeter of the canopy caught significantly more female moths than traps placed within the canopy and surrounded by foliage. Smaller trap surfaces caught significantly more males than females. Traps placed adjacent to uninjured fruit caught significantly more females than traps placed away from fruit. No difference in moth catch occurred in traps placed adjacent to injured versus uninjured fruits. These data are useful in standardizing the use of pear ester lures for monitoring codling moth and in improving the trapping of female moths for lure and kill strategies.