The pickle worm life cycle is approximately one month. Overlapping generations occur. Their minute eggs are white when deposited on the buds, flowers, and other portions of the plant , but change to yellow after the first day. They are distributed in small groups, usually less than a dozen per cluster. Hatching takes about four days.
Larval development time is about two weeks. After which the moths emerge, they are primarily nocturnal. Moths are not found in the field during the daylight hours, and probably disperse to adjacent wooded or weedy areas during the heat of the day. Moths do not produce eggs until they are several days old. Praying Mantids are recommended if not used in conjunction with chemicals as they as well as bats are among the few nocturnal predators of moths.
The pickleworm can cause severe damage. Young pickleworms generally feed on small leaves at the growing tips of vines or within blossoms. When they about half grown, they bore into fruits and continue to feast , causing internal damage and leaving behind an excrement trail. Fruits at all stages of development are attacked, but young fruits are attacked more frequently. Pickleworm holes lead to decay and rot, cantaloupes and muskmelon develop a sour taste.
Control of the Pickleworm
Diverse gardens that include a symbiotic mingling of flowers and vegetables are a poor environment for insect pests as they also attract many natural predators. Pickleworms have several natural enemies, such as Lady Bugs. Praying Mantids will feed on the moths by night.
Beneficial nematodes when sprayed directly on the plant do a good job, they survive several days inside the flowers where the pickleworms roam and can greatly deplete their populations. None of the predators will eliminate pickleworms entirely. Bt is the safest and surest weapon against this pest. Bt is rarely harmful to beneficial insects.
Bt bacillus thuringiensis is the best bet against pickleworm, it is a bacterium that is known to kill all worms, and is readily available to home gardeners. It's harmless to people and pets. Apply it at either bloom or petal fall, or both. B It is a stomach poison and must be ingested . It is more effective when applied during warm, dry weather while the larvae are actively feeding. Bt breaks down quickly in nature so multiple treatments per season is necessary.
Diazinon can be applied at petal fall, but is not as eco-friendly as the bio-pesticides listed above as it is toxic to beneficial insects and pollinators.