dogwood borer

not listed

NNR - Unranked

not listed

Dogwood borer is a small clearwing moth. It occurs in southeast Canada and in the United States east of the Mississippi River. It is less common in Minnesota where it is at the western edge of its range. It is a major pest of pecan and flowering dogwood.

Adults look convincingly like a wasp. They are 5 ⁄16″ to ½″ long and have a wingspan of 9 ⁄16″ to ¾″. They are mostly black or metallic bluish-black with yellow markings.

The thorax is dark with a yellow longitudinal line on each side. The abdomen is dark with a thin yellow band on the second segment and a thicker one on the fourth segment. On the female, the band on the fourth segment is much thicker. A rounded tuft of long hairs (anal tuft) flares outward from the last abdominal segment. The anal tuft is mostly black with a few to many yellow hairs on both lateral margins and sometimes also in the middle.

The forewings are 3 ⁄16″ to ⅜″ long, narrow, and rounded at the tip. They are longer and much narrower than the hindwings. They are mostly free of scales (clear) with a black border, a black bar through the discal area, a yellow patch near the tip, and dark scales along the veins. The leading (costal) margin is black with narrow yellow streaks. The hindwing is entirely clear except for dark scales along the veins. It has a dark fringe of short hairs. As with most moths, the hindwings and forewings are held in contact by bristles (a frenulum) and scales (a retinaculum). Unlike most moths, they are also held together by a rolled under inner margin of the forewing coupling with a rolled up costal margin of the hindwing.

Total length: 5 ⁄16″ to ½″

Wingspan: 9 ⁄16″ to ¾″

Deciduous woods, parks, yards

Probably just one generation per year: May to September in Minnesota

Adults are active during the day.

The female lays single pale yellow eggs in the wound of a tree. She lays up to 100 or more eggs throughout the year. When an egg hatches in eight or nine days, the larva burrows under the bark. The larva will pass through seven stages (instars). In the fall it creates a cocoon-like shelter (hibernaculum) within the feeding gallery and overwinters. It resumes feeding in the spring, spins a cocoon, and emerges as an adult about 25 days later.

A wide variety of deciduous trees, including dogwood, black cherry, American plum, Canadian plum, pecan, hickory, oak, beech, birch, elm, mountain-ash, viburnum, willow, apple, blueberry, pine, willow, hazel, and ninebark.

Sources

21, 30, 75.

Uncommon