Dustywings / Home and Landscape / UC Statewide IPM Program (UC IPM)

Hosts or Prey

All stages of mites and various, small, soft-bodied insects on foliage and green shoots

Identification

Adults at rest are about 1/8 to 5/16 inch (3–7 mm) long, head to wing tip. The long, thin antennae are commonly held in front of the body and have numerous, beadlike, segments. The wings are covered with gray to white, powdery wax, as may be the body, head, legs, and basal portion of antennae. At rest the wings are held rooflike over the body. However females of Helicoconis species can be wingless.

Eggs are oval, somewhat flattened, and slightly pointed at one end where a tiny tube projects. Eggs are 1/24 inch (1 mm) long or less and whitish, pale orange, pink, or yellowish with netlike markings on the surface.

Larvae and pupae are elongate and 1/5 inch (5 mm) or less in length. They have distinct segments and a body that tapers narrowly toward the rear. The mouthparts of larvae are short, tubelike, and not apparent without magnification. Mature, inactive larvae (prepupae) and pupae occur curled within a flattened, roundish, silken cocoon.

Lookalikes

Adults can be mistaken for adult whiteflies, but dustywings have much longer antennae and legs. Whiteflies suck plant sap and are prey of dustywings, so both insects can occur together.

Adults at rest when viewed from the side have antennae, bodies, and wings the same shape as those of brown lacewings and green lacewings, but their coloration generally differs. In comparison with other Neuroptera (the order of net-winged insects) dustywings have no more than two costal crossveins (those just below the upper margin of forewings) and overall have relatively few wing veins. In comparison brown lacewings and green lacewings have numerous wing veins including numerous costal crossveins.

Larval shape of dustywings also resembles that of brown and green lacewings. However, unlike the inconspicuous mouthparts of dustywing larvae brown and green lacewing larvae have forward-projecting, pointed, tubelike mouthparts that are obvious without magnification.

Life Cycle

Dustywings develop though 4 life stages: egg, larva, pupa, and adult. An adult female during her lifetime lays about 200 eggs singly on bark or leaves. After hatching, larvae develop through 3, increasingly larger instars before pupating.

Dustywings have 2 or more generations per year. Egg to adult development time is about 6 to 8 weeks when temperatures are warm. They overwinter as adults in sheltered locations or in cocoons as prepupae (inactive, mature larvae) that in spring pupate into adults.

Habitat

Dustywings occur mostly on shrubs and trees. They are easily overlooked because of their small size and the adults' resemblance to whitefly adults. Adults are active mostly at dawn or dusk when they flutter slowly between foliage to lay eggs. They can also be attracted to lights. Eggs and larvae occur in colonies of prey. Cocoons are found on bark or the underside of leaves.

Dustywing adults and larvae feed mostly on soft-bodied, sedentary or slow-moving arthropods such as aphids, mealybugs, mites, phylloxera, psyllids, scales, and whiteflies. Although dustywings in general consume a wide variety of small arthropods, many species are specific to certain plants, such as junipers. They consume the particular arthropods found on preferred hosts and can be important biological control agents of certain plant feeders. For example, a larval dustywing can consume about 150 to 300 aphid eggs or young nymphs (immatures) or mites before metamorphosing to a pupa.

Species

At least 7 genera and 28 species of dustywings occur in California. These include Conwentzia and Helicoconis spp. and 5 or more species each of Aleuropteryx, Coniopteryx, and Semidalis.