American plum borer

Systematic position: The American plum borer (Euzophera semifuneralis) belongs to the order Lepidoptera and the family Pyralidae. It is a significant pest of orchard trees, known for its ability to cause extensive damage to the bark and cambium layers of woody plants.

Host plants: This pest primarily targets stone fruits, including plum, peach, apricot, and cherry. It can also infest pome fruits such as apple and pear, especially when the trees have existing bark wounds, sunscald, or pruning cuts that provide favorable egg-laying sites.

Biology and life cycle: The species overwinters as late-stage larvae in cocoons located beneath the bark or in deep crevices of the trunk. Pupation occurs in the spring, followed by the emergence of adult moths. Adults are nocturnal, and females deposit eggs near bark cracks or wounded areas on the trunk and scaffold branches.

Damage symptoms and harmfulness: Upon hatching, larvae tunnel into the bark and feed on the cambium layer, creating complex galleries. This activity disrupts nutrient transport, weakens the tree structure, and causes branch dieback. Heavily infested trees show stunted growth and are prone to secondary infections by pathogens entering through the larval galleries.

Control measures: Effective management requires both cultural and chemical practices. Key strategies include

• maintaining tree vigor to promote callus formation over wounds;
• proper pruning to reduce entry points;
• applying registered insecticides targeting the egg-laying period and young larvae before they penetrate the bark.