Synanthedon scitula
James Solomon, USDA Forest Service
The Dogwood Borer is a
moth that looks a lot like a small wasp. Adult borers are
about 1 centimeter long. They have bluish-black bodies with
yellow stripes. Females have more yellow than males. The
wings of this moth are clear. Dogwood Borers can be
found wherever their favorite trees live, including
forests,
parks, and yards. Adult Dogwood Borers
become active in late May. They only live for about a week,
so they need to find a mate quickly. After mating, female
borers lay eggs on wounds in trees. Some tree species they
use include: Flowering Dogwood, American Beech, elms, oaks,
birches, Black Willow, blueberries (shrubs),
American Chestnut, hickories, and pines. University of Missouri
Extension, http://muextension.missouri.edu
Cornell
University Adult Female Dogwood
Borer Cornell
University Adult Male Dogwood
Borer
Larvae
hatch from eggs in about nine days. Dogwood Borer larvae
look like grubs;
they are whitish with pale brown heads. The larvae bore
(burrow) into the tree’s bark.
They continue to bore and eat the bark, making huge
galleries. A gallery is a network of tunnels made by many
borers. Larva will overwinter
underneath the bark. In Spring, Dogwood Borer
larvae become pupae
(resting stage). They make a dark brown cocoon
with silk and frass (poop). The cocoon is usually near the
surface of the bark. A little less than a month later,
adult
borers leave their cocoons and start the cycle
again. Michigan State University
Extension, Van Buren County Dogwood Borer
Larva
|
Michigan State University Extension, Van Buren County Dogwood Borer In Pupa Case |
Not all Dogwood Borers emerge in late May. They come out a few at a time until September. The later borers lay their eggs last, and their larvae will be the last to hatch that year. Those larvae will then be the last to pupate the following Spring. Larvae are only a couple of millimeters long when they are first born, but are about 1 centimeter when they are full grown. If you were to look inside a borer gallery, you would probably see larvae of all different sizes. You could tell which ones hatched first, and which ones hatched more recently. |
James Solomon, USDA Forest Service
