Pest Management Science (2021) 77, 1626-1632

Peter Yeeles, Angela Strain, Pauline Lenancker and Lori Lach (2021)
Low reduction of invasive ant colony productivity with an insect growth regulator
Pest Management Science 77 (4), 1626-1632
Abstract:
BACKGROUND
Insect growth regulators (IGRs) generally are considered to have safer eco-toxicological profiles than the more commonly used neurotoxins and metabolic inhibitors, and are extremely effective against several insect groups, including some invasive ant species. However, use of an IGR product in a large-scale eradication program for a widespread invasive ant (Anoplolepis gracilipes; yellow crazy ant) was ineffective. We tested the IGR in question (active ingredient: (S)-methoprene) on A. gracilipes colonies in a laboratory environment to evaluate efficacy.
RESULTS
We found that treatment with (S)-methoprene resulted in lower egg production with subsequently decreased numbers of larvae, pupae, and workers over the 135 days of the experiment. None of the treated colonies died, and the number of worker ants in treated colonies was 36% of that seen in control colonies 135 days post-treatment. Treated queen egg production was 39% lower than queens in control colonies, but we saw no effect of treatment on the internal physiology of dissected queens. Treatment had no effect on worker activity levels.
CONCLUSION
Our results show that although (S)-methoprene treatment reduced production of larvae, pupae and workers in treated colonies, the magnitude of reduction was lower than might be expected considering the responses of other species against which this IGR has been tested. Our findings highlight a need for testing species-specific responses to IGR-based insecticides in a controlled environment, before broad-scale field applications that could result in suboptimal management of the target species.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website

Research topic(s) for pests/diseases/weeds:
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Anoplolepis gracilipes		Australia (NT+QLD)