White ermine

The White ermine (Spilosoma lubricipeda) is a moth of the family Erebidae. Although it is a common sight in gardens and parks, it is frequently classified as a minor to moderate agricultural pest due to the voracious appetite of its larvae, which can impact a wide range of herbaceous and woody plant species.

The host range of the White ermine is extensive. It infests various vegetable crops including potatoes, brassicas, and root crops, as well as soft fruits and ornamentals. Because the caterpillars are polyphagous, they do not rely on a single plant source, which allows the species to maintain population stability across diverse agricultural environments.

The life cycle of Spilosoma lubricipeda typically involves one or two generations per year depending on the climatic conditions. The moths emerge in late spring or summer. Eggs are laid in clusters on the leaves of host plants. The larvae pass through several instars, feeding gregariously when young and dispersing as they mature, eventually overwintering as pupae in cocoons hidden within plant debris or soil.

Damage is characterized by extensive leaf consumption. Young larvae feed by skeletonizing the underside of leaves, while older larvae consume the entire leaf lamina, often leaving only the main veins. This damage reduces the photosynthetic capacity of the plant, leading to stunted growth, loss of vigor, and potentially significant yield loss if infestations are left unchecked.

Effective management requires an integrated approach. Cultural controls such as autumn soil cultivation help destroy pupation sites. On a smaller scale, handpicking clusters of young larvae is highly effective. For larger infestations, applying organic insecticides or products containing Bacillus thuringiensis is recommended when larvae are in their early instars to maximize efficacy and minimize environmental impact.

• Monitor for egg batches on leaves during the flight season.
• Remove leaf litter to reduce potential overwintering sites.
• Utilize row covers on susceptible young vegetables.
• Employ biological control agents to manage caterpillar populations.