Pest Of The Month: Melonworm

Pest Of The Month: Melonworm

Advertisement

 

 

 

Identification

Top Articles
Healthy Soils at Center of New $5 Million Initiative for California Citrus Growers

The moths are relatively small with a wingspan of about one inch. The wings are white and edged with dark brown. The eggs are very small, and flattened ovals in shape. They are white or greenish initially but quickly turn yellow.

Newly hatched larvae are colorless; but after molting, become yellow-green. The last instar has two white stripes running the length of the body. The stripes disappear when the caterpillar pupates. The pupa is dark brown and often found in a loose cocoon in a fold of a leaf.

Survival And Spread

Melonworm occurs throughout most of Central and South America and the Caribbean. The U.S. is the northern limit of its range. This pest is present throughout the year in South Florida but disperses northward each year as the weather warms up. Melonworms usually reach North Florida in June and can complete several generations before the onset of cold weather.

Moths are active at night and rest under leaves during the day. They deposit their eggs in small clusters in buds, stems, and leaves. The larva feeds on leaves and occasionally on the surface of fruit.

Melonworm feeds principally on foliage, especially if foliage of a favored host plant, such as summer or winter squash, is available. Usually the leaf veins are left intact, resulting in a lace-like appearance.

If the available foliage is exhausted, or the plant is a less preferred species such as cantaloupe, the larva may feed on the surface of the fruit, or even burrow into the fruit. Growers sometimes refer to these insects collectively as “rindworms” as they can cause scars on the surface of melons.

Management Methods

Early plantings of squash, cucumbers, and cantaloupe, especially in North Florida where melonworm does not normally overwinter, may escape damage.

Check plants regularly for signs of feeding damage to leaves and for the presence of larvae.

Since pollinators, particularly honeybees, are very important for good fruit set in cucurbits, insecticides applied for melonworm control must be applied when bees are not actively foraging. Bacillus thuringiensis can be very effective.

Many other excellent lepidopteran materials present on the market so growers have a number of options available. Consult UF/IFAS recommendations for currently labeled insecticides for melonworm control.

Destruction of crop residue, which might contain melonworm pupae, is highly recommended.

More than a half dozen parasitoid wasps and flies are known to attack larvae and eggs. Several beetles and red imported fire ant also attack larvae and eggs.

1