Clearwing Moths

Clearwing Moths also called Wasp Moth are long-legged with a slender, dark body with bright red or yellow markings. The wings frequently lack scales and are transparent. Unlike those of other moths, the front and back wings are hooked together by a series of curved spines (similar to the wasps they mimic). Many of the species resemble wasps, which is a form of protective mimicry. Larvae are pale, wormlike borers, often injurious to cultivated plants. They bore in roots and stems for about one year and usually pupate in their burrows

Identification: Dying limbs, rough or gnarled bark, and sawdustlike frass (insect excrement) are good indications that trees are infested with wood-boring insects. Clearwing moth adults have long, narrow front wings and shorter, wider hind wings. The hind wings, and in some species the front wings, are mostly clear. These moths fly during the day or at twilight, and their yellow and black coloring resembles that of paper wasps or yellowjackets. Adults display wasplike behavior by intermittently running while rapidly fluttering their wings. They differ in color depending on species and sex. They are often yellow, orange, or red on black or dark blue.

Life Cycle: Clearwing moths develop through four life stages: egg, larva, pupa, and adult. Adults do not directly damage plants and live only about 1 week. Soon after emerging from the pupal case, female moths emit a pheromone that attracts males. After mating, the female deposits her tiny reddish to pale pink eggs in cracks, crevices, and rough or wounded areas on bark. Eggs hatch in about 1 to 4 weeks. The newly emerged larvae bore into the bark, cambium, or heartwood of the host tree. Mature larvae pupate beneath bark, except for the peachtree borer, which pupates in soil. The species discussed here have one generation per year except for the western poplar clearwing, which requires 1 to 2 years to complete one generation.

Damage: Clearwing moth larval feeding can cause tree bark to become gnarled or rough. Borer feeding can damage the plant’s food- and water-conducting tissues. With some clearwing species such as those that attack sycamore and pine, feeding is tolerated by trees and apparently causes no serious harm. Feeding by other species can weaken or kill branches. Branches weakened by larval tunneling may break and fall, especially during windy weather. Sometimes entire trees may die. Other types of wood-boring insects produce similar damage.

Management:  Mature woody plants usually tolerate and can recover from the attack of a few clearwing moth larvae. However, the presence of this pest often indicates that plants have been injured, stressed, or neglected. Providing trees with appropriate cultural care is the primary damage prevention strategy. Sometimes larvae can be killed by puncturing or crushing them. Heavy infestations of clearwing moths may warrant treatment with beneficial nematodes to kill larvae, broad-spectrum insecticides to kill adults, or both.

controls: Clearwing moths are killed by various parasites and predators, including small Apanteles spp. braconid wasps. For example, Apanteles paranthrenidis often parasitizes poplar clearwing larvae. Larvae parasitized by Apanteles spp. have many small, oblong, white cocons adhering to their bodies. A minute blackish brown wasp emerges from each cocoon after the larva dies. The importance of parasites and predators in reducing clearwing moth populations has not been documented, but avoid disrupting natural enemies whenever possible, for example by not spraying trees that tolerate borers and by using physical controls and preventive cultural methods

Clearwing moths are attracted to tree wounds. Avoid pruning live branches unless necessary to develop tree structure or remove severely infested, dying, or hazardous limbs. Except for hazardous limbs that should be removed whenever they appear, prune only during fall through early winter to minimize the chance of attracting egg-laying moths.

If you have any questions about pest control check out the rest of our website or go to our blog at http://nypestpro.blogspot.com.

Beyond Pest Control.

Our pest control specialists service all NYC boroughs, including Queens, Brooklyn, Bronx, Manhattan, Long Island (both Nassau & Suffolk counties), Staten Island and even both Westchester & Rockland counties.