Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 25, 2000
Publication Date: December 1, 2000
Citation: Knight, A.L. 2000. Tebufenozide targeted against codling moth (Lepidoptera: Tortricidae) adults, eggs, and larvae. Journal of Economic Entomology. 93:1760-1767. Interpretive Summary: The effectiveness of a newly registered insecticide, tebufenozide was evaluated for codling moth eggs, larvae, and adults. Tebufenozide is an insect growth regulator that impacts the normal development of various life stages. Tebufenozide is a promising new insecticide for pest management because it does not impact the natural enemies of the important orchard pests. I demonstrated in a combination of laboratory and field trials that contact of adult moths with residues of tebufenozide reduces the number of eggs laid and the percentage of eggs that hatch. Tebufenozide also directly kills codling moth eggs. Greenhouse studies demonstrated that tebufenozide is only marginally effective in preventing fruit injury by codling moth larvae. Spray timing trials demonstrated that the best fruit protection was provided by applications of tebufenozide timed against the presence of adults and eggs. Sprays timed later that coincided with egg hatch and larval penetration of fruit were not as effective. These results have provided clear guidelines on how to use this new material for effective management of codling moth.
Technical Abstract: The effectiveness of tebufenozide applied against codling moth, Cydia pomonella (L.) was evaluated. Significant reductions in fecundity & egg hatch occurred following 1-h and 24-h exposures of females and 24-h exposures of males-only to residues. A significant reduction in egg hatch was found following a 1-h exposure of males. The ovicidal effects of tebufenozide in field trials did not significantly differ for eggs laid on residues or treated topically. Corrected egg mortality exceeded 95% for cohorts laid <130 degree days after sprays were applied. Fecundity & egg hatch were measured following a 24-h exposure of moths or a 10-d exposure of moths and eggs on apple trees. Significant reductions in both fecundity & fertility occurred compared to an untreated check up to 7 d in the 24-h assays & accounted for 60-70% fewer larvae produced per mated female. The mean numbers of larvae produced per mated female following the 10-d exposure were reduced 100 to 75% in assays started on day 0 to 21 following the spray application compared with the untreated check. Fecundity was significantly reduced for 7 d & egg hatch was reduced for the entire 21-d test. Residues had a 14-d half life on foliage. Residues applied to foliage & fruit did not significantly increase the proportion of uninjured fruit compared with the untreated check. Field applications of tebufenozide reduced fruit injury >90% when applied early during emergence. Plots treated had a larger proportion of injured fruits with shallow larval feeding.