Melonworm, Diaphania hyalinata Linnaeus (Lepidoptera: Pyralidae)

Melonworm is a tropical insect, and occurs throughout most of Central and South America and the Caribbean. It also occurs in some subtropical locations, such as the southernmost United States. Melonworm disperses readily, invading areas where it cannot overwinter, so occurrence in the cooler portions of its range is variable, depending on wind and favorable weather.

Life History

The melonworm can complete its life cycle in about 30 days. It is present throughout the year in warm locations, undergoing numerous generations annually, but has as few as one generation in peripheral, invaded areas.

Melonworm moths (Fig. 28) deposit oval, flattened eggs in small clusters, averaging 2–6 eggs per egg mass. Apparently they are deposited at night on buds, stems, and the underside of leaves. Initially they are white, but soon become yellow in color. They measure about 0.7 mm long and 0.6 mm wide. Hatching occurs after 3–4 days.

There are five instars. Total larval development time is about 14...