Grape colaspis

The Grape colaspis (Colaspis varia) is a beetle belonging to the order Coleoptera and the family Chrysomelidae. Despite its common name, it is a significant pest of various field crops, including corn and soybeans, causing economic losses across many agricultural regions.

This pest is polyphagous, meaning it feeds on a wide range of host plants. Adults typically damage the foliage of host crops by chewing irregular holes in the leaves. However, the most severe damage is often caused by the larvae, which live underground and feed on the roots of young seedlings.

The biological cycle consists of four stages: egg, larva, pupa, and adult. The insect usually overwinter as larvae deep in the soil profile. As temperatures rise in the spring, the larvae move toward the surface to feed on newly developed roots before pupating and emerging as adult beetles.

Visible damage includes leaf defoliation by adults and stunted growth or wilting of young plants due to root feeding by larvae. Severe root pruning can lead to significant stand loss, especially under stress conditions like dry weather or nutrient deficiency in the field.

Managing this pest requires an integrated approach. Crop rotation is one of the most effective cultural practices to reduce larval populations. Furthermore, insecticide seed treatments are widely used to protect early-stage crops from soil-dwelling larvae, alongside foliar sprays for adult beetle outbreaks.

• Implement systematic crop rotation practices.
• Use insecticide-treated seeds during planting.
• Monitor adult beetle populations with traps.
• Apply foliar insecticides at economic thresholds.