Effect of temperature on common cutworm occurrence (Spodoptera litura Fabricius)

Abstract

To study the relationship between temperature and occurrence (annual total) of the common cutworm, Spodoptera litura Fabricius, the results of pheromone trap surveys conducted over the past 40 years (1985–2024) by the Mie Prefectural Plant Protection Office were analyzed. A positive correlation (r = 0.68) was found between the average temperature from April to November and total catch number, with hotter years tending to have a higher occurrence. When the results were subdivided by decade, variation became progressively smaller, and the correlation over the last 20 years was higher (r = 0.83).