Insect growth regulator impact on fecundity and fertility of adult tufted apple bud moth, Platynota idaeusalis Walker

The tufted apple bud moth, Platynota idaeusalis Walker, is a major pest of apples in the eastern United States. Resistance to conventional insecticide chemistries has made this pest difficult to control. The insect growth regulators (IGRs) tebufenozide and methoxyfenozide, which are target-specific to lepidopteran pests, have been shown to have high efficacy against P. idaeusalis larvae. These compounds are known to affect adult moths in related tortricid species, but the effects of exposure on adult P. idaeusalis are unknown. This study investigated the effects of adult exposure on the fecundity and fertility of P. idaeusalis. Both tebufenozide and methoxyfenozide significantly reduced the fecundity and fertility of female P. idaeusalis adults that were exposed to dry films of formulated IGR residue. Female fecundity and fertility also were reduced when untreated or treated females mated with treated males. Contrary to other related studies, there was no difference in fecundity/ferfility reduction efficacy between tebufenozide and methoxyfenozide. Thus, because tebufenozide and methoxyfenozide have reproductive activity against adults, such compounds may bring significant benefits to integrated pest management (IPM) of tree fruits.