Elm prominent

The elm prominent (lat. Exaereta ulmi) belongs to the order Lepidoptera and the family Notodontidae. This insect is a significant pest of hardwood trees, primarily focusing on species of the genus Ulmus, which can suffer severe defoliation during outbreaks of the moth.

The biological cycle consists of one generation per year. The species overwinters in the pupal stage, buried within the soil or deep inside the leaf litter in protective cocoons. Adults emerge in spring, with females laying eggs in clusters on the undersides of host leaves.

The larvae are responsible for all damage. Upon hatching, young caterpillars feed gregariously, skeletonizing the leaves. As they grow, they disperse throughout the canopy, consuming entire leaves and leaving only the main veins, which severely stresses the host tree.

Significant infestations can lead to substantial loss of leaf surface area, which weakens the trees and makes them more susceptible to drought, secondary infections, and attacks by wood-boring insects. This is particularly problematic in urban forestry and sensitive ecosystems.

Management strategies for this pest include:

• Frequent monitoring of tree crowns for early detection of egg clusters.
• Manual removal and destruction of infested foliage in smaller ornamental settings.
• Application of microbial insecticides based on Bacillus thuringiensis for eco-friendly control.
• Use of systemic insecticides in nurseries or high-value landscapes when damage thresholds are exceeded.