Poplar hawk-moth

The Poplar hawk-moth (Laothoe populi) is a member of the Sphingidae family within the order Lepidoptera. This large moth is recognized by its distinct resting posture, resembling withered leaves. While generally not considered a major agricultural pest, it can cause localized damage to specific tree species in nurseries, parks, and silviculture settings.

The primary host plants for the larvae (caterpillars) are species within the Salicaceae family, most notably poplars (Populus spp.) and willows (Salix spp.). Aspen trees are also targeted. Given their high food intake, large infestations can significantly affect the growth of young trees in decorative gardens or plantations.

The life cycle involves complete metamorphosis, consisting of eggs, larvae, pupae, and adults. Females deposit eggs singly on the underside of host leaves. Upon reaching maturity, the caterpillars descend from the host tree to pupate in the soil at the base of the tree. The species typically overwinters in the pupal stage, buried within the leaf litter or soil.

The damage caused by the Poplar hawk-moth is strictly defoliation. Caterpillars feed on the leaf blades, starting from the edges or creating irregular holes. In cases of high pest density, they can strip entire branches of foliage. While mature trees usually tolerate this, younger plants or those already under stress may suffer from reduced photosynthetic capacity and stunted growth.

• Monitor leaf surfaces for eggs and young larvae during mid-summer.
• Manual removal of caterpillars in small gardens or young plant collections.
• Encouraging natural predators such as birds and parasitic wasps in the environment.
• Applying biological pesticides like Bacillus thuringiensis where chemical alternatives are restricted.
• Autumn soil cultivation under the canopy to disrupt pupae survival in the ground.