Northern Survivor: can we outwit, outplay, and outlast Spodoptera litura?

Abstract

Bollgard® 3 was anticipated to provide greater protection against a wide range of lepidopteran pests. However, since its introduction in northern Australia in 2017, Spodoptera litura larvae have been intermittently observed surviving in crops. The ability of larvae of all instars to survive has raised questions about the factors enabling survival, their potential to complete development, and broader implications for pest management. Despite its historical importance in the Ord River Irrigation Area, our understanding of S. litura in Bollgard® 3 cotton remains limited. This raises a critical question: what factors explain the intermittent survival of S. litura in Bollgard® 3 fields in northern Australia? Investigating this question is critical for the sustainability of Bt cotton as the cotton expands across northern production systems. This presentation will examine how the survival of larvae reflects a combination of biological susceptibility, behavioural movement, and environmental conditions, and consider the implications for integrated pest management in cotton crops across northern Australia.