Management options for reducing the reliance on insecticides for fall armyworm in sweet corn (VG23006)

What was it all about?

This project investigated practical ways to manage fall armyworm (FAW) in sweet corn and capsicum while reducing reliance on broad‑spectrum insecticides.

The research confirmed that the widely grown sweet corn variety Garrison has very little tolerance to FAW feeding during vegetative growth. Even low infestations caused major yield and quality losses, meaning an economic threshold could not be set and a zero‑tolerance approach remains necessary with current varieties. The project also showed that natural enemies, particularly the egg parasitoid Trichogramma pretiosum, can play a meaningful role, with 20–60 per cent of FAW egg masses parasitised in field trials.

The project worked with growers through area‑wide management groups in Queensland to test non‑chemical and IPM‑compatible options. Trials evaluated floral resources such as buckwheat, intercropping systems, biopesticides, and pheromone traps. Buckwheat and other refuges supported beneficial insects without major production downsides, but their impact on fall armyworm infestation needs further investigation. The trials showed that commercial FAW nucleopolyhedrosis virus products alone did not provide reliable control under moderate to high pressure. Pheromone traps showed potential for tracking moth activity but need further work before they can guide in‑crop decisions. Glasshouse studies confirmed capsicum is not a preferred FAW host, with infestations more likely from spillover rather than direct egg‑laying.

For growers, the findings reinforce the importance of protecting sweet corn crops early, highlight the value of conserving natural enemies, and provide clearer guidance on FAW risk and monitoring in capsicum. The project also delivered trial reports (available in the Final Report) and a capsicum factsheet (available here) to support on‑farm decision‑making and future research priorities.