Beet armyworm

Spodoptera exigua is a highly dispersive, polyphagous species that is a serious pest of vegetable, field and flower crops. Susceptible crops include asparagus, cabbage, pepper, tomato, lettuce, celery, strawberry, eggplant, sugar beet, alfalfa, and cotton.

S. exigua is native to Southeast Asia but is now found in Africa, Southern Europe, Japan, Australia and North America. It lacks a diapause mechanism and can only overwinter successfully in warm regions or in greenhouses. Nevertheless, because of its dispersal abilities,  S. exigua will regularly invade temperate areas and cause damage during the growing season. The larvae are gregarious and may feed in large swarms, causing devastating crop losses. Larvae feed on both foliage and fruit and cause contamination of the crop. As they mature, the larvae become solitary. One generation can be produced in as little as 21-24 days.