Identification


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Thanks to WSDA’s consistent trapping and eradication efforts, gypsy moths are rare in Washington. Because of this, it is unlikely that current gypsy moth populations will leave significant signs of their presence, such as defoliation or caterpillar droppings. Instead, you must look for the moth itself at its various life cycle stages. Below you will find detailed information on how to identify gypsy moths as well as common imposters. For more information, you can watch our gypsy moth video.

Female Adult Gypsy Moth

Female gypsy moths are a light cream color with wide abdomens and short, thin antennae. Their wings have brown zigzag stripes. European females do not fly, while Asian gypsy moth females can.

Generally seen July to October

Male Adult Gypsy Moth

Male gypsy moths are darker and smaller than the females. They are a tan brown color and have dark zigzag markings on their wings. They also have distinct, hairy antennae which they use to located females by scent.

Generally seen July to October

Gypsy Moth Egg Masses

Females lay distinct, fluffy egg masses that can range in color from brownish orange to off white. Each egg mass can contain 1,000 eggs or more. Egg masses are laid in late summer and overwinter to hatch late in the spring when trees have leafed out.

Generally seen July to May

Gypsy Moth Caterpillars

Gypsy moth caterpillars start out extremely tiny but rapidly grow up to 3 inches long. As they grow, they can be readily identified by their yellow head, hairy body, and distinct 5 pairs of blue dots followed by 6 pairs of red dots on their backs.

Generally seen April to July


Gypsy Moth Impostors

The tent caterpillar is very common in Washington and is much less destructive than the gypsy moth. Tent caterpillars produce large web-like tents each spring. Gypsy moths do not build tents. Tent caterpillars tend to have orange and blue markings, lacking the distinctive blue and red dots of the gypsy moth caterpillar.

Pacific Tent Caterpillar

Western Tent Caterpillars

Adult tent caterpillar moth and eggs

Female and male tent caterpillar moths

Tent caterpillar egg mass

Tent caterpillar "tent"

Fall Webworm

The fall webworm, as its name implies, appears in the fall and begins to feed on trees. They produce webs or tents much like the spring-feeding tent caterpillar. The caterpillars are usually brownish in color and lack the blue and red spots of the gypsy moth. Adults are seldom mistaken for gypsy moths, as they are white and lack markings.

Fall webworm on leaf

Fall webworms

Fall webworm web

Female fall webworm laying eggs

Fall webworm laying eggs

Adult fall webworm