Small white

The small white (Artogeia rapae) is a common butterfly belonging to the Lepidoptera order and the Pieridae family. It is widely recognized as a serious agricultural pest, causing significant economic losses to both commercial farms and home gardens across many temperate regions of the globe.

The pest primarily targets plants within the Brassicaceae family. Key host plants include various types of cabbage, broccoli, cauliflower, Brussels sprouts, kale, radish, turnip, and horseradish. Its ability to feed on almost any brassica crop makes it a persistent threat throughout the entire growing season.

The insect undergoes complete metamorphosis consisting of four life stages: egg, larva (caterpillar), pupa, and adult. Depending on local climate conditions, the species produces multiple generations annually. Pupae serve as the overwintering stage, often found on plant debris, garden fences, or structures, allowing for rapid colonization in the spring.

Damage is primarily inflicted by the larval stage. Young caterpillars skeletonize leaves by consuming the tissue while leaving the veins intact. As they grow, they move into the heart of the crop, creating large, irregular holes and contaminating the produce with frass. This behavior severely degrades quality and can render crops unsuitable for market.

Effective management requires an integrated approach. Cultural practices include weeding out wild mustard and other cruciferous weeds, crop rotation, and physical barriers such as floating row covers. For chemical control, selective insecticides or biological treatments, such as Bacillus thuringiensis sprays, are highly effective against larval populations.

• Regular inspection of the undersides of leaves for eggs.
• Encouraging natural predators and parasitoid wasps.
• Sanitation of fields by removing crop residues after harvest.