Adult beetles have a thin body that varies in color from olive to copper-bronze.
They range in length from 6 to 12 mm, with females being somewhat bigger than males.
The eggs are 1.5 mm long, oblong, and flattened. They start as a white color but eventually turn yellow.
The body of the larvae is whitish, thin, and segmented. They have a light-brown head and are legless. At the apex of the abdomen, there are two brown pincer-like features.
The larvae can grow to reach up to 35 mm long when fully grown.
Pupae start white, much like the larvae, but as they grow older, they darken and become more like the adult color.
Host plants:
Other birches are also attacked, but white, cut leaf, and yellow birches are favored.
Territory:
Its native habitat in North America flourishes under a wide range of ecological and climatic conditions.
Damage caused by Bronze Birch Borer:
The adult beetle is a copper/bronze slender insect. Because the larvae that cause the harm devour the vascular tissue beneath the bark, they go undetected. The Bronze Birch Borer prefers to feed on trees already stressed or dying. A birch infected with the Bronze Birch Borer will develop crown dieback, which will worsen as the disease progresses and eventually destroy the tree. As the tree tries to grow over larval galleries, the trunk may exhibit D-shaped, rust-stained exit holes and swelling extrusions beneath the bark in later stages of infection.
Life history and Habits:
The bronze birch borer contains a single generation per year. In most parts of Canada, adults are active from June through August. Adults are vigorous flyers, capable of flying hundreds of kilometers in search of host trees. Adults eat birch, poplar, and alder leaves. However, there is no significant defoliation as a result of their grazing. Females deposit eggs in bark fissures and cracks after mating. Clusters of eggs are frequently laid. Larvae emerge and mine in the cambium and phloem, forming crisscross tunnels. Later, the larvae dig into the sapwood to hibernate for the winter. There are four or five instars in the larval stage. Mature larvae pupate in oblong cells in the bark in the spring, while young larvae feed again. Emerging adults nibble through the bark after the pupal stage, leaving a distinctive D-shaped exit hole. The bronze birch borer has a one- to the two-year life cycle, depending on where it is found. The cycle is one year in the warmer southern parts of its range and two years in the cooler northern parts.
