Small white

The small white (scientific name: Artogeia rapae, often classified as Pieris rapae) is a common butterfly of the Pieridae family. It is recognized as one of the most significant pests affecting cruciferous crops worldwide, impacting both commercial agriculture and home gardening.

The pest primarily targets plants in the Brassicaceae family. This includes a wide range of crops such as all varieties of cabbage, broccoli, cauliflower, Brussels sprouts, kale, radishes, turnips, and oilseed rape. Young seedlings are particularly vulnerable to infestation by early-stage larvae.

The biological cycle follows a complete metamorphosis: egg, larva (caterpillar), pupa, and adult. Eggs are laid singly on the undersides of leaves. Depending on the temperature, the species can produce multiple generations per year. The insect typically overwinters as a chrysalis in sheltered areas or on plant debris.

Larvae cause damage by feeding on leaves, creating large, irregular holes that reduce the plant's photosynthetic capacity. In cabbage heads, the caterpillars tunnel deep into the heart of the plant, which not only causes direct yield loss but also introduces secondary bacterial infections and rot.

Integrated Pest Management (IPM) is essential for effective control. This includes monitoring for egg batches, encouraging natural predators like parasitic wasps, and maintaining crop rotation. In cases of severe infestation, chemical control with pyrethroids or biological control using Bacillus thuringiensis sprays should be initiated promptly.