Boxwood Leafminer Fact Sheet

The good news about the boxwood leafminer is there are effective control options.

Boxwood leafminer fact sheet.

Infested leaves are spotted yellow and may drop prematurely. The infested leaves appear blistered from late summer through the following spring. The adult leafminer is a yellow to orange red fly that looks like a mosquito. Mines are not evident for several weeks.

Boxwood leafminer is the most destructive insect pest of boxwood. The leafminer is the larva immature form of a small orangish mosquito like fly. When the boxwood s new growth appears in spring the females mate then insert their eggs into the underside of the leaves. These flies are less than inch long and can often be seen swarming around boxwoods in the spring.

The larvae of this fly feed on the tissue between the outer surfaces of the leaves. The adult fly dies soon after. We have seen severe leafminer populations kill boxwood. Adult flies swarm around boxwoods about the time that the weigelas bloom.

This is the most serious insect pest that attacks boxwood. Conspicuous egg punctures in leaves. This feeding results in blotch shaped mines in the boxwood leaves. Over the period of several years a lightly infested plant can become discolored brown and even defoliated.

New leaves do not show signs of mining until late summer when the larvae are larger. Common boxwood buxus sempervirens symptoms. Oval water soaked swellings on the lower leaf surface evident from midsummer until shed. Boxwood leafminer monarthropalpus flavus.