How Can I Get Rid Of The Pests That Attack My Cranberries?

Do you have problems with blackheaded fireworms, cream to gray-green caterpillars that cause webbing on growing tips of fresh growth and feed on lower leaf surfaces?

Do you have problems with cranberry blossomworm, green caterpillars that turn reddish-brown as they mature and cause feeding damage to leaves and buds?

Do you have problems with cranberry fruitworms, small, pale-yellow larvae of a gray-brown moth that burrow into the berries and feed on the pulp?

Do you have problems with cranberry tipworms, tiny maggots that are initially clear but change to white and finally orange as they mature?

Do you have problems with cranberry weevils, reddish-brown beetles with an elongated snout that causes flowers to turn orange instead of pink and make numerous holes in berries?

Reflooding the beds for between 24 and 48 hours after eggs have hatched will kill off a high number of larvae. Application of BTK (Bacillus thurengiensis) may reduce the populations of larvae on the plants.

Insecticide application is recommended for commercial production if the number of blossomworm larvae reaches the threshold of 4.5 larvae per 25 sweep net samples (sweep netting must be done at night as the insect is nocturnal).

Late flooding of the cranberry plantation (30 days reflood before the end of dormancy) can successfully reduce the activity of the fruitworms. Chemical control includes several broad-spectrum insecticides for commercial use but must be applied at the egg stage to be effective as larvae that have already entered the fruit are shielded from the chemical.

Because cranberry tipworm larvae and adults are so small, they are difficult to monitor. Sanding the cranberry bushes is an effective method of controlling insect emergence as it prevents adults emerge from pupae in the soil. Natural enemies include hoverflies and some species of parasitic wasp.

Cranberry weevil populations usually remain low. But if the population had reached a threshold of 4.5 weevils per 25 sweep net samples, the use of registered chemical insecticides is the best control method.

If you have problems with gypsy moths, black caterpillars covered in hair-like structures that feed on the foliage and terminal buds you can control them by using BTK (Bacillus thurengiensis) spray or by reflooding the beds for 24 hours.