Australian entomologists have evaluated two IGRs for their effectiveness against codling moth and other pests of apple, and for their impact on predators in the orchard. Tebufenozide and fenoxycarb were compared with the commonly-used broad-spectrum organophosphate, azinphos-methyl. Fruit damage was very low and equivalent across the three treatments. However, in both years of the study, spider mite levels were higher in the azinphos-methyl treatments than in either of the IGRs. The differences in pest mites could not be attributed to predatory mites, because the levels of these were comparable in all three treatments. However, spiders, a predatory bug, and the mite-predatory beetle Stethorus all were significantly reduced in the azinphos-methyl treatments compared to the IGRs. The authors of this study conclude that the two IGRs tested could provide good target pest control while fitting into a mite IPM program.

The two products tested in Australia are not currently registered for use on apple in the U.S. Further, other studies have shown that there may be negative impacts of specific IGRs on specific beneficials, indicating that each situation may have to be studied individually. However, it does appear that the IGRs as a group may have a future role in conserving beneficials in apple IPM programs.

Source:

Valentine, B. J., G. M. Gurr, and W. G. Thwaite. 1996. Efficacy of the insect growth regulators tebufenozide and fenoxycarb on lepidopteran pest control in apples, and their compatibility with biological control for integrated pest management. Austr. J. Exper. Agric. 36:501-506.