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Old World Bollworm
old world bollworm adult
old world bollworm adult
Order: Lepidoptera
Family: Noctuidae
Scientific name: Helicoverpa armigera
Common name: old world bollworm (OWB)


old world bollworm adults have a 3.5-4 cm wing span and are yellowish tan in color with medium brown markings.
Larvae: young caterpillars are mostly green; mature caterpillars are usually striped with a base color of green, brown, or black.
Pupae: reddish brown and can be found in the soil
Eggs: newly laid eggs are domed shaped, pearl white, and ribbed; the eggs darken as they mature

Damage: The larvae damage all plant parts. The most damage is caused when the larvae feed on the buds, flowers, and fruits of their host plants.

Impacts: Old world bollworm causes large crop losses. It is considered a very serious pest in countries where it is established. It has the potential to become a serious pest of many different crops in the US.

Host plants:
Larvae are nearly omnivorous (highly polyphagous), feeding on many important crops including alfalfa, apple, barley, cabbage, cauliflower, corn, cotton, daisies, fruit trees (pome and stone fruit), green beans, hollyhock, kale, marigold, onion, pine trees, potato, sorghum, soybean, strawberry, wheat, tomato, and more. OWB larvae feed on host leaves and flowers, causing damage to seedlings, crop quality, and reducing crop yield.

Distribution: OWB is native to Europe and Asia. It is also present in Africa, Australia, New Zealand, Malay Archipelago, Bulgaria, Greece, Portugal, Romania, Spain, Cyprus, France, parts of Hungary and Italy.

Biology and Life Cycle: Adult female moths generally lay their eggs on the flowering parts of plants. They can lay 500 to 3,000 eggs in a lifetime. The number of generations each year is highly dependent on local climates, and can range from two to five in temperate regions. In Oregon we might expect to see adult activity starting as early as April 15th, and lasting into fall. They overwinter as pupae. The adults are highly migratory and can fly more than 100 kilometers.

What ODA is doing: ODA is placing approximately 100 OWB traps across the state. Placing traps allows ODA to detect any infestations when they are small and when they are more easily eliminated.

Invasive.org OWB webpage

OWB images