Purple-edged copper

Systematic position. The Purple-edged copper (Palaeochrysophanus hippothoe) belongs to the order Lepidoptera and the family Lycaenidae. While many butterflies in this family are considered beneficial or neutral, the larvae of this species can act as pests on specific agricultural crops.

Crops and damage. The pest primarily targets plants within the Polygonaceae family. In agricultural settings, it is known to feed on sorrel, rhubarb, and occasionally buckwheat. Larvae consume leaf tissue, often causing skeletonization of the foliage, which reduces the plant's ability to undergo photosynthesis and diminishes the commercial quality of leafy green produce.

Biology and life cycle. This butterfly undergoes complete metamorphosis. Adults are typically active during summer months, favoring damp meadows and field margins. Females lay eggs on the undersides of host plant leaves. Larvae overwinter in the early instars, sheltering at the base of plants or among debris. They resume feeding in the spring, progress through several larval stages, and pupate on stems or foliage.

Economic importance. Although the Purple-edged copper rarely reaches outbreak levels, it can be a persistent nuisance in fields where sorrel is cultivated for market. Its impact is most significant when high densities of larvae feed on the crop during the spring growing season, leading to direct yield loss and increased management costs.

Control measures. Effective management relies on a combination of cultural and preventive methods:

• Elimination of wild Polygonaceae weeds in and around cultivated fields to remove alternative food sources.
• Inter-row cultivation to disrupt the larvae's overwintering sites in the soil and plant residue.
• Application of biological pesticides (such as Bt-based products) when young larvae are detected.
• Judicious use of chemical insecticides only when damage exceeds economic thresholds, adhering to safety periods.