Top Insect Threats in Western Vegetables

Western flower thrips
With pepper production in high gear in several regions of CA, damaging pests are on the minds of many growers. Stay on top of these top threats in peppers and other vegetable crops this season by learning how to identify and treat when these pests are in the field.
Beet armyworms
- Larvae are up to 25 mm long.
- Larvae have smooth bodies with predominant green color and mottled dark lines along the back.
- Potential for multiple generations per season.
The beet armyworm is a prevalent pest in peppers and can cause both defoliation and fruit loss as a result of larvae feeding. Adults lay eggs on young plants, where larvae hatch and begin to feed near the egg cluster. They can skeletonize leaves and feed on young fruit as the larvae grow.
Vegetable leafminer
- Larvae are about 2.25 mm in length.
- Larvae are colorless at first, turning greenish and yellowish as the mature, with black mouths.
- Potential for multiple overlapping populations per year.
Vegetable leafminer larvae cause the most damage of any developmental stage. The larvae feed on a range of crops, leaving irregular mines across the foliage. Larvae mine through the foliage after hatching and are often visible in the leaf tissue through the mine. Additional damage is possible by adult females, which poke holes in leaves as they lay eggs and feed.
Western flower thrips
- Adults are 1.5 mm in length.
- Adults are pale yellow to light brown in color.
- Potential for multiple generations per season.
In peppers, western flower thrips are a vector of Tomato Spotted Wilt Virus (TSWV). In addition, thrips cause damage by feeding, which impacts plant growth, deforms flowers, and causes patches of white-to-silvery discoloration on emergent leaves.
These insect pests migrate from host to host throughout the year and can result in significant yield losses if not properly managed. Take the Insect IQ Quiz to test your knowledge of insect pests. If you are a certified crop adviser (CCA), you’ll be eligible to receive CEUs for completing the quiz.
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