Rose Stem Girdler – Bronze Cane Borer – Agrilus aurichalceus

Rose Stem Girdler: Appearance, Territory, Damage and Life Cycle

Latin Name: Agrilus Aurichalceus Trunk and Branch Borers

Appearance: In central and northern Utah, the rose stem girdler is a common cane-boring beetle of raspberry and blackberry. It was originally documented in Utah in 1955 in American Fork. It is now a widespread cane-boring pest of raspberry, blackberry, and wild rose in the state’s central and northern districts. The mature rose stem girdler beetle measures around 3/8 inch (9-10 mm) in length and has a flattened body shape. Adults are unlikely to be spotted. The larva is cream-colored, has a big head, and is segmented. Larvae cannot be seen on the plant’s outer surface.

Hosts Plants: Currant, gooseberry, raspberry, rose

Territory: In central and northern Utah, the rose stem girdler is a common cane-boring beetle of raspberry and blackberry.

Damage Insect Cause: The larva of the rose stem girdler feeds just beneath the bark of rose stems. Its feeding stops the flow of water and nutrients in the stem, causing the stem above the feeding spot to perish. The stem swells right below the dead zone as well. The flathead borer larva digs meandering tunnels beneath the bark of roses, cane berries (raspberry, blackberry, and so on), currants, and gooseberries. A swelling region forms surrounding the injured portion of the stem, which is typical. Canes frequently die back or break at these injured areas. Wearing garden gloves, remove adult beetles and caterpillars from the rose plants on a regular basis. Put the beetles and caterpillars in a pail of soapy water with liquid dish detergent to kill them right away.

Life History and Habits: The bronze cane borer spends the winter as a nearly fully formed larva beneath the bark of the canes or within the pith. It resumes eating and pupates within the plant in the spring. The adult stage is a bronze-colored beetle that emerges in May and remains until early June. During this time, eggs are deposited, generally near the base of the leaves. The larvae that hatch from the eggs burrow through the bark and climb higher in the plant. These early tunnels are frequently near to the surface and may be visible from the outside on some plants, such as roses. Later, they burrow further into the canes, causing the harmful girdling wounds. Pupation takes place within a chamber formed within the cane the following spring. Each year, one generation is born.