Cucumber Moth (Diaphania indica) — identification, habitat & look-alikes

The cucumber moth is a small moth whose caterpillars chew the leaves of cucumbers, squash, melons, and other gourds. Its glossy, see-through white wings have wide dark brown edges. In the United States it has been found in Florida but is not widespread in the rest of the country.

Appearance

Appearance: Wingspan is about 1–1.2 in (2.5–3 cm). The wings are translucent white with a broad dark brown border, and the head, thorax, and tip of the abdomen are brown. Females carry a noticeable tuft of light brown scales at the tip of the abdomen, and unmated females often sit with it spread, releasing scent; in males the tuft is tiny.

Look-alikes

Melonworm mothDiaphania hyalinata

The two look very much alike and can't be reliably told apart from photos; experts check the genitalia or the pupae. Location helps: the melonworm lives year-round in southern Florida and spreads north each summer through the southeastern states, while the cucumber moth in the U.S. is known from Florida.

Why they get mixed upBoth are white moths with dark borders whose caterpillars feed on squash and melons.

Where it lives

Typical habitats: vegetable gardens
farm fields
greenhouses
Range: Native to southern Asia, it has spread through tropical and subtropical Asia, Australia, Pacific islands, and parts of Africa. In the U.S. it is present in Florida but is not widespread in the rest of the country.
Preferred conditions: Found where its host plants, mainly gourd-family crops, are grown.

Behavior

Diet: Caterpillars feed mostly on leaves of the gourd family, and also on some legumes, cotton, and eggplant. When they are numerous, they may also damage the fruit.

Life cycle

Larva: Full-grown caterpillars are about 1 in (2.4 cm) long, pale green with two white stripes down the back. They tie leaves together with silk and feed inside.
Caterpillar food plants: Cucumbers, squash and pumpkins, melons, luffa, bitter melon, and other gourds; also some legumes and cotton.