General Information

Scientific name: Melittia cucurbitae, M. satyriniformis, M. calebaza
Lepidoptera:Sesiidae

Host plants

Squash, zucchini, pumpkins, and other gourds

Distribution

In areas where squash is grown

Damage

Attacked plant suddenly wilts. A larva bores into the stem, usually at the lower part, one meter from the plant's base. Damaged vine often rots and becomes wet and shiny. Heavily infested ones die depending on the number of borers and their location.

Description

Eggs are ovoid, flattened, dark-reddish-brown in color, and about 1 mm in diameter. They are laid singly in the vine near the base of the plant but can also be found on leafstalks and underneath the leaves. They hatch in 9-14 days.

The larva is a fat grub-like and whitish caterpillar that has a wrinkled body with a brown head. A fully-grown larva can measure up to 2.5 cm in length. It enters the stem a few hours after it has been hatched, stays and feeds there for 4-6 weeks. It leaves the stem when the vine wilts and/or crawls into the soil when it is ready to pupate.

The pupa is brown and 1.6 cm long, and is contained inside a cocoon that is made of earth-covered black silk. It is found usually 2.5-5 cm deep in the soil. Prior to moth emergence, the pupa moves upward to the soil surface by wiggling its abdomen. It splits behind its head and after 5 minutes, the moth frees itself. In another 15 minutes, the moths' body hardens and is ready to fly. The pupal stage lasts up to 2-3 weeks (Bauernfeind, R.; Nechols, J. 2001).

The adult (moth) is colorful and looks similar to a wasp. Its body is black, marked with an orange-red color and with a red abdomen. The hind legs are feathery with black and orange hairs. Its front wings are metallic-green while the hind wings are transparent. It has a wingspan of about 2.5-3.7 cm. The female can lay up to 250 eggs a day. The moths are active during daytime, this differentiates them from the other Lepidoptera, who are active at night. They are found resting on the leaves at night time.