Greetings from the Veg IPM team! Here are the most recent pest and disease issues we’re seeing in various vegetable crops.
Cole Crops
Flea beetle surrounded by feeding damage. Picture by Maria Cramer.
In some parts of NJ we are still detecting flea beetles in various cole crops. This year, they have been especially prevalent in Napa cabbage, Tuscan kale, and bok choy. Young plants are especially vulnerable to attack from flea beetles. For all growth stages of heading cole crops, the threshold is 50% plants with flea beetles present before sprays will pay off.
Left: Diamondback moth caterpillar, showing characteristic tapering at each end. Right: Imported cabbageworm caterpillar showing characteristic fuzziness. Pictures by Maria Cramer.
We’re also seeing caterpillar activity (imported cabbageworm and diamondback moth) in cabbage and other cole crops. Treatment thresholds vary between crops and growth stage, but for heading cole crops between early vegetative and cupping, the treatment threshold is 30%. At this stage, sprayable Bt products (IRAC 11A) such as Dipel, Xentari, or Javelin can be effective on young caterpillars and will also be gentle on natural enemies that control other cole crop pests. Other materials approved for caterpillar control include Entrust/Radiant (IRAC 5), Proclaim (IRAC 6), Torac (IRAC 21A), Exirel (IRAC 28), and the new product Incipio (IRAC 30). These additional products may work better for diamondback moth or larger larvae. For Bt products and contact insecticides, coverage on the undersides the leaves is essential.
Tomatoes
In high tunnel tomatoes, we’re seeing limited thrips (A), aphid (B) and spider mite (C) activity. At this stage, we recommend avoiding broad spectrum products that can flare up secondary pests unless absolutely necessary, so be sure to base interventions on seeing threshold-level pest problems. Consider spot treatments for aphids and spider mites. Additionally, biological control agents can be used in tunnels to help suppress pest populations. If primarily dealing with aphids or thrips, products such as Beleaf (IRAC 29) are recommended, especially if plants have reached the flowering stage.
From left to right: (A) an adult thrips, (B) aphids, and (C) a two-spotted spider mite. Photos by Amanda Quadrel.
We have also identified several tomato spotted wilt virus cases in south Jersey greenhouses and tunnels (see below). It’s important to identify and remove infected plants to prevent the spread of the virus, in combination with monitoring and managing western flower thrips populations. More information on managing thrips. If you need help identifying tomato spotted wilt virus, please contact us using the form at the bottom of this post.
Tomato spotted wilt virus symptoms on a greenhouse tomato. Picture by Maria Cramer.
Sweet Corn
We’ve put out a few corn earworm pheromone traps throughout the state. While silking corn is the main target of CEW activity, we set the traps early to detect overwintering moths, which have become more common with warmer winters. Official maps with statewide CEW activity will be shared starting in June. So far in scouted corn, we have not seen any major issues. There have been some instances of flea beetle, spotted cucumber beetle, and caterpillar feeding, but these insects are incidental feeders that are not likely to reach economically damaging levels.
Spotted cucumber beetle and feeding damage on sweet corn. Photo by Maria Cramer.
As a reminder, the new 2026/2027 Mid-Atlantic Commercial Vegetable Production Guide is now available both online (click here) and as spiral-bound hard copies in county extension offices. Consult this guide for a more comprehensive list of materials that are labeled for specific crops and pests.
Authors: Amanda Quadrel (Northern NJ Veg IPM coordinator) and Maria Cramer (Southern NJ Veg IPM coordinator)
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