by Gene McAvoy, 5-County UF/IFAS Veggie Agent.
Around SW Florida, worm pressure is starting to increase and scout report finding more southern and beet armyworm eggs recently along with loopers, hornworms and fruitworms. Melonworms have been very active in cucumber and squash.
Melonworm feeds only on cucurbits and is one of the most important pests of vine crops in Florida. Summer squash and the winter squash species are favored hosts. Cucumbers and cantaloupe are attacked but not preferred.
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 as collectively as "rindworms".
The moths are relatively small with a wingspan of about 1 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 pupa is dark brown and often found in a loose cocoon in a fold of leaf.
Moths are active at night and rest under leaves during the day. They deposit their eggs in small clusters in buds, stems and leaves.
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 (Bt) can be very effective.
Read more here: http://www.growingproduce.com/
