Soybean looper (Chrysodeixis subsidens)

Systematic position: Chrysodeixis subsidens is a member of the order Lepidoptera and the family Noctuidae. It is recognized as a significant agricultural pest, particularly known for its impact on various broadleaf crops and leguminous plants in specific geographic regions.

Host plants: The pest is a polyphagous insect that attacks a wide range of economically important crops. Common hosts include soybeans, alfalfa, cotton, various brassicas, and solanaceous crops like tomatoes. Dense populations can cause substantial defoliation, leading to stunted plant growth and reduced biomass.

Biology and life cycle: The lifecycle of this moth consists of egg, larva, pupa, and adult stages. Females lay their eggs on the underside of leaves. The larvae, often referred to as loopers due to their characteristic movement, feed voraciously. The pupal stage typically occurs within a silk cocoon found on the host plant or among leaf litter.

Damage and economic impact: Larval feeding is the primary cause of damage. Young larvae graze on the underside of leaves, while older instars consume large portions of leaf tissue, leaving behind only the veins. In severe infestations, the larvae may feed on flowers and developing pods, which directly impacts yield quality and quantity for the harvest.

Management strategies: Integrated Pest Management (IPM) is essential for controlling this species. Control measures include:

• Regular field scouting to monitor egg and larval density.
• Encouraging natural biological control agents such as parasitic wasps and predatory bugs.
• Using biorational insecticides, including nucleopolyhedroviruses (NPV) or Bacillus thuringiensis.
• Applying synthetic insecticides only when economic thresholds are exceeded.