Adults can be found on dead log piles and frequently emerge from firewood.įigure 1. Red-headed ash borers feed in many species of wood including ash, oak, elm and even grapes. The antennae are rather short and the long legs are thin and fragile. The yellow lines are slanted downward toward the middle, giving the appearance of a “V” across the back. It has a narrow body with a reddish thorax and light brown wing covers marked with four yellow lines on each. Red-headed ash borer (Neoclytus acuminatus) is one of the most common wood-boring beetles. The larvae (1.75 to 2 inches long) tunnel at the base of the trunk or below ground level. Adult beetles are large (1 1/4 inches long) with an attractive black and whitish-yellow pattern. In a year the larvae are fully grown and about an inch in length.Ĭottonwood borer (Plectrodera scalator) is frequently found on cottonwood, poplar or willow trees. Later, larvae tunnel into the inner bark and construct cells in which they spend the winter months.

Visible symptoms of infestation are wet spots and frass on the bark of black locusts. Larvae hatch from eggs laid in bark crevices. They are dark brown to black with distinctive gold-yellow markings. Locust borer (Megacyllene robiniae) adults are medium-sized (3/4 inch long) long-horned beetles frequently found feeding on goldenrod or other f lowers in the fall. Some examples of long-horned beetles are described below. Many species of beetles belong to this group, but most are secondary invaders. This excrement, along with the sap exuded by the plant in response to the damage, is often visible on the outside of infested trunks or branches. While tunneling, larvae continually pack their tunnels with excrement (frass) which looks like compressed wood fibers, or push frass out of the holes they produce. Larvae of some species are legless, but most have three pairs of small legs on the first three segments behind the head capsule. The tunnels are oval to almost round in cross section because of the round shape of the larvae (See Fig. Larvae tunnel underneath bark and into the heartwood. Long-horned beetles or round-headed borers ( Coleoptera: Cerambycidae)Īdults are called long-horned beetles because their antennae are occasionally longer than their bodies. Borer damage can severely affect the quality of lumber and can make trees susceptible to dis-ease. On occasion, tunneling makes the tree weak, causing limbs and branches to fall. Partial girdling reduces plant growth and vigor above the site of attack. When the cambium layer is completely girdled the plant eventually dies above or beyond the damage site. Many borers damage plants by tunneling through the inner bark layer (cambium) into the sapwood (xylem) that transports nutrients and water to the leaves. One woodpecker, the yellow-bellied sapsucker, produces square holes in rows around a trunk or branch.

Woodpecker damage is sometimes confused with that of wood-boring beetles, however woodpecker damage will not produce frass.

Their holes are normally round, oval or semicircular and are found in a random pattern on the plant. Wood-boring insects often produce sawdust-like frass (excrement). Wood-boring insects that attack healthy trees and shrubs are called “primary invaders.” Primary invaders may eventually kill trees.īorer infestations often go unnoticed until plants or parts of plants begin to die or show external signs of damage. Many other insects live in dying or dead trees, including natural enemies (predators and parasites) of the insect borers, sap or fungi feeders, or species which merely use the spaces provided by the tunnels and galleries as living quarters. Secondary invaders include species from groups already mentioned, but also may include termites, carpenter bees and carpenter ants. Secondary invaders are a symptom of other problems with the health of the tree or shrub, but may contribute to its decline. These are referred to as “secondary invaders” because they attack only after a plant has been weakened by another stress. Most insect borers are attracted to weakened, damaged, dying or dead plants. Bark beetles and insect borers belong to several different insect groups including a variety of beetles, moths and horntail wasps. Many insects feed and make their homes in the bark, trunks and branches of shade trees and shrubs in Texas.

Merchant, Assistant Professor and Extension Urban Entomologist Jackman, Professor and Extension Entomologist Drees, Professor and Extension Entomologist

Maple trees in texas