Boxwood Leafminer Fact Sheet

We have seen severe leafminer populations kill boxwood.

Boxwood leafminer fact sheet.

Common boxwood buxus sempervirens symptoms. This is the most serious insect pest that attacks boxwood. Boxwood leafminer monarthropalpus flavus. These flies are less than inch long and can often be seen swarming around boxwoods in the spring.

Oval water soaked swellings on the lower leaf surface evident from midsummer until shed. Over the period of several years a lightly infested plant can become discolored brown and even defoliated. The leafminer is the larva immature form of a small orangish mosquito like fly. Boxwood leafminer presence is indicated by blistering or irregularly shaped swellings on the leaves.

Conspicuous egg punctures in leaves. Adult flies swarm around boxwoods about the time that the weigelas bloom. Boxwood leafminer is the most destructive insect pest of boxwood. Infested leaves are spotted yellow and may drop prematurely.

The good news about the boxwood leafminer is there are effective control options. Blistering is most apparent on the undersides of the leaves and becomes most obvious late in the. The infested leaves appear blistered from late summer through the following spring. This feeding results in blotch shaped mines in the boxwood leaves.

The adult leafminer is a yellow to orange red fly that looks like a mosquito. When the boxwood s new growth appears in spring the females mate then insert their eggs into the underside of the leaves. The larvae of this fly feed on the tissue between the outer surfaces of the leaves. The adult fly dies soon after.