Submitted to: Journal of Applied Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/25/2011
Publication Date: 1/31/2012
Citation: Knight, A.L., Stelinski, L.L., Hebert, V., Gut, L., Light, D.M., Brunner, J. 2012. Evaluation of novel semiochemical dispensers simultaneously releasing pear ester and sex pheromone for mating disruption of codling moth (Lepidoptera: Tortricidae). Journal of Applied Entomology. 136:79-86. Interpretive Summary: Management programs developed for codling moth using sex pheromones for mating disruption have been widely adopted by apple and pear growers in the western United States. However, further improvements in the efficacy of this technology could precipitate greater reductions in growers’ supplemental use of insecticides. One promising approach has been to add pear ester, a natural volatile released by ripe pear fruits, to the sex pheromone to enhance the level of mating disruption. ARS researchers at the USDA, ARS, Yakima Agricultural Research Laboratory, Wapato, WA in collaboration with ARS researchers in Albany, CA; and scientists at Washington State and Michigan State Universities tested dual dispensers loaded with sex pheromone and pear ester and compared them with dispensers loaded only with sex pheromone. In general, dual dispensers performed similarly to commercial dispensers loaded only with sex pheromone. However, the dual dispensers outperformed the sex pheromone dispensers during a portion of each field season. These results support the need for expanded evaluations of dual dispensers in order to obtain the optimal loading and ratio of each component. Successful development of a more efficacious dual dispenser should improve management of and allow more judicious use of insecticides targeting codling moth.
Technical Abstract: The performance of polyvinyl chloride polymer (pvc) dispensers loaded with two rates of ethyl (E,Z)-2,4-decadienoate (pear ester) plus the sex pheromone, (E,E)-8,10-dodecadien-1-ol (codlemone) of codling moth, Cydia pomonella (L.), was compared with similar dispensers and two commercial dispensers loaded only with codlemone. Dispenser evaluations were conducted in replicated small (0.1 ha) and large (2 ha) field trials in apple during 2006 and 2007. Data recorded included male captures in traps baited with virgin female moths and codlemone lures and direct observations of moth behavior in treated plots. Volatile air collections of field-aged dispensers were conducted under laboratory conditions. Disruption of male catch in codlemone-baited traps was generally similar among dispenser treatments, except for two instances: lower moth catches with the single and dual-component pvc dispensers, compared with Isomate®, during the first flight in the large plots in Michigan in 2007 and for the dual-component pvc dispenser compared with the CheckMate® dispenser during the second flight in small plots in Washington in 2006. Levels of fruit injury were similar in large plots treated with all dispensers. Male moth catches in virgin female-baited traps did not differ among dispenser treatments and were significantly lower than the untreated control. Behavioral observations of adult moths in the field verified approaches within 20 cm of pheromone dispensers loaded with and without pear ester that lasted ca. 15 s on average. Field-aged dual-component dispensers released pear ester at a > 5-fold higher rate than codlemone over the first 8 wks and this ratio declined to near unity by 18 wks.