Tackling insecticide resistance in Helicoverpa armigera

Helicoverpa armigera has historically been very good at developing resistance to insecticides. So good in fact, this serious pest has become the focus of a new resistance management strategy.

Selective chemistries at risk

Group 28 (chlorantraniliprole) and Group 22A (indoxacarb) are two newer, selective chemistries now widely available for control of Helicoverpa armigera (aka the cotton bollworm) in pulses.

Softer, selective insecticides have the benefit of largely maintaining the beneficials in our crops.

But like any chemistry, if not used judiciously, they are at risk of losing efficacy as pests develop resistance to their mode of action.  

­­Recent results from annual resistance testing of H. armigera undertaken by NSW DPI (with support from CRDC & GRDC) indicate that indoxacarb is at risk of field failures due to genetic factors and increasing levels of resistance in NSW and Queensland.

Chlorantraniliprole is also at risk because of emerging resistance in some regions and the heavy reliance of this product in pulse crops.

Curbing insecticide resistance

To mitigate these risks, the first resistance management strategy is now available to support growers to effectively manage H. armigera.

The strategy has been developed by the National Insecticide Resistance Management (NIRM) working group of the Grains Pest Advisory Committee and endorsed by CropLife Australia.

While the strategy focuses on chickpeas and mung beans in northern regions, the principles can be applied to other grain crops.

The strategy is primarily built around use windows for chlorantraniliprole and indoxacarb to reduce selection across consecutive generations of H. armigera, but its success will rely on an integrated approach. This includes minimising the risk of pest build-up on in-crop weeds, pupae-busting the stubble of treated fields which may harbour overwintering pupae, and using the softest chemistries available to preserve beneficial insects.

Helicoverpa armigera is more common in the northern and coastal regions of eastern Australia, but are occasionally problematic in south-eastern Australia in late spring and summer.

Growers and advisors are advised to become familiar with, and to follow the principles of the strategy when managing H. armigera.

The strategy can be downloaded at: https://grdc.com.au/GRDC-FS-Helicoverpa-resistance-management

Cover image: Photo by Andrew Weeks, Cesar Australia

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PestFacts south-eastern keeps growers and advisers informed about invertebrate pests and beneficials in broadacre crops and pastures during the winter-cropping season in Victoria and southern New South Wales.


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Since 2019 PestFacts south-eastern has been running through IPMforGrains: Best Practice Insect Pest Management, a project delivered by the National Pest Information Network (Cesar Australia, DPIRD, QDAF, NSW DPI, and SARDI). This project aims to provide grain growers and advisors with information on invertebrate grain pest occurrence and equip industry with the knowledge needed to implement integrated pest management practices. This initiative is a GRDC investment and includes in-kind contributions from all project partner organisations.

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