December moth

Systematic position. The December moth (Poecilocampa populi) belongs to the order Lepidoptera, family Lasiocampidae. It is a nocturnal moth species widely distributed across Europe, typically inhabiting woodland areas, hedgerows, and garden environments where suitable host trees are present.

Affected crops. The larvae of this moth are polyphagous, feeding on a wide variety of deciduous trees. Major hosts include poplar, willow, birch, lime, oak, and alder. In agricultural settings, they are known to attack various fruit-bearing trees such as apple, pear, plum, and cherry.

Biology and life cycle. This species completes one generation per year. Adult moths emerge in late autumn, often active during cold nights. Females lay their eggs on the bark of twigs, which remain in overwintering stage until the spring. Upon hatching, larvae emerge synchronously with the budding of host trees, feeding actively until early summer before pupating in a sturdy cocoon.

Damage symptoms and harmfulness. Early larval stages cause skeletonization of the leaves. As they mature, larvae consume the entire leaf lamina, often leaving only the main veins. High infestation levels cause extensive defoliation, which severely stresses the host plant, reduces growth vigor, and makes trees more susceptible to secondary pests and diseases.

Control measures. Integrated pest management involves several strategies:

• Manual removal of egg masses from twigs during the dormant season.
• Application of microbial insecticides, such as Bacillus thuringiensis, during the early larval stage.
• Use of chemical insecticides if thresholds are exceeded.
• Conservation of natural predators, such as birds and parasitic wasps, to suppress larval populations naturally.