Mottled umber

Systematic position. The mottled umber moth (Hibernia tiliaria, syn. Erannis defoliaria) belongs to the order Lepidoptera, family Geometridae. It is a well-known defoliating pest that periodically causes significant damage to both forest ecosystems and ornamental or fruit-bearing plantations.

Host plants. This species is polyphagous, meaning it feeds on a wide range of woody plants. While it shows a preference for deciduous forest trees such as lime (linden), oak, birch, and beech, it frequently attacks fruit trees, including apples, pears, cherries, and plums, causing major agricultural losses.

Biology and life cycle. The species follows a univoltine life cycle (one generation per year). Unlike many other moths, the adults emerge in late autumn. The females are flightless and climb tree trunks to lay eggs in bark crevices. The larvae hatch in the spring, coinciding with bud burst, and feed voraciously on the foliage until early summer, before descending to the soil to pupate.

Damage and economic impact. Larval feeding begins with minor skeletonization, but as the caterpillars grow, they consume entire leaves, leaving only veins. Severe infestations can lead to total defoliation of the tree. This significantly stresses the plant, reduces fruit production, weakens the overall immunity of the tree, and may lead to secondary pest and disease susceptibility.

• Applying sticky bands to trunks in autumn to prevent flightless females from climbing up.
• Mechanical removal of eggs and damaged plant material during winter pruning.
• Monitoring the population density at the bud burst stage to determine the need for chemical control.
• Using selective biological insecticides, such as BT-based products, to protect beneficial insects while controlling larvae.