Whitemarked Tussock Moth – Orygia leucostigma

White Marked Tussock Moth – Origin leucostigma Scientific Name: Origin leucostigma, Orgyia (Hemerocampa) leucostigma (J. E. Smith) Common Name: White Marked Tussock Moth, Rusty Vapor Moth Distribution: The caterpillar is widespread throughout eastern North America, reaching as far west as Texas, California, and Alberta, and is most prevalent in the late summer. Host plants: There are more than 140 identified hosts, such as larch, apple, balsam fir, birches, and alder. Identification: Caterpillars are remarkable in that they have four brush-like tufts or bunches of light tan hairs on the back, along with red spots. They grow to a length of 1-1/4 inches. A lighter-haired tuft emerges from the back of the body, and two longer tufts of black hair emerge from the front. The body is cream in color overall, with a reddish-orange head, a large black stripe on the back, and a broader gray stripe along either side. The male moth has an ash gray body with a wing span of approximately 1 1/4 inches. The forewing is spotted with darker, wavy streaks. Females lack completely formed wings and range in color from white to gray. Life Cycle: In Florida, the other two species are bivoltine, but Orgyia detrita is univoltine (generating one generation annually). The overwintering eggs in Florida start to hatch in late February. Following hatching, the young larvae consume the leftover egg mass before spinning a silk thread to help them “balloon” and spread. Since adult females cannot fly, the primary method of dissemination is ballooning by immature larvae. Considering their inclination to spin cocoons off of their host plants, ballooning is equally significant. The larvae’s short hair pencils allow for easy identification by the time they reach the second instar. Tiny larvae consume leaf holes. Older larvae feed on the edges of leaves. From mid-April until early May, adults emerge. Following mating, the females immediately place a large quantity of eggs on top of the cocoon and cover them with a covering for protection. For all three species, the overwintering stage is the egg stage. Damage: Craving mouthparts are found in caterpillars. Adults’ mouths are siphoning. Apple, basswood, elm, maple (Norway and silver), pear, plums, poplars, rose, sycamore, willow, wisteria, and other plants are examples of caterpillar host plants. The southern subspecies consumes redbud, mimosa, pyracantha, and live oak. While adult larvae devour all of the leaf surface save for the bigger veins, younger larvae skeletonize leaves. Management: The fact that illnesses, parasites, and predators abound in white marked tussock moth caterpillars may help to explain why they are not frequently widespread pests. The caterpillars have most likely completed eating by the time they are generally observed, and they are looking for a place to spin their cocoons. It is a waste of time to apply a pesticide to adult, migratory caterpillars since they have a high tolerance to insecticides. When the caterpillars are young and actively eating is the ideal time to spray. Even formulations of Bacillus thuringiensis can provide sufficient control at that point.