Development and survival of Plutella Xylostella in central Argentina: Estimating key parameters for local populations.

Abstract

Diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae), a globally distributed insect, is a major pest of crucifer crops due to its adaptability to diverse climates. In Argentina, its distribution spans three regions: a core area in the northeast and central-east where it persists year-round, a southwestern region with seasonal migrations, and an intermediate zone with variable year-round persistence. Across these areas, it is the primary pest of Brassica crops. In the central-east, the availability of year-round Brassicaceae crops and wild species indicates that seasonality is not linked to food scarcity. While studies have examined this relationship elsewhere, thermal thresholds vary among populations, and limited data on South American populations highlight the need for localised research. This study evaluated thermal thresholds for P. xylostella populations in central Argentina, focusing on temperature's effects on fecundity, fertility, development, and survival. We found that temperatures outside the optimal range (15-23°C) significantly reduced survival, with no individuals surviving at 5 or 30°C. Linear and non-linear models accurately described the relationship between temperature and pest development. Using cumulative degree-days, we mapped potential P. xylostella generations across central Argentina. This research provides the first comprehensive analysis of P. xylostella thermal biology in temperate Argentina, emphasising temperature's critical role in its development. The findings offer valuable insights for climate-specific pest management strategies and enhance understanding of insect population dynamics in agricultural ecosystems, contributing to more sustainable control practices.