Vegetable IPM Update 5/15/25

Greetings from the Veg IPM team! No major changes have taken place between last week and this week, and with the rainy weather, scouting has been limited.

Sweet Corn

We’ve put out 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. As a reminder, we’re no longer using blacklight traps as of this year, and we’ll be reporting pheromone trap counts in the Plant Pest Advisory as the season progresses. So far, we haven’t spotted any corn pests through visual inspection.

Cole Crops 

A shiny black beetle with straight antennae stands on a leaf surrounded by circular feeding holes.

Flea beetle surrounded by feeding damage. Picture by Maria Cramer.

Flea beetle are active in various cole crops. This year, they have been especially prevalent in Napa cabbage and bok choy. Young plants are especially vulnerable to attack from flea beetles. The treatment threshold for flea beetles in heading cole crops is 50% infestation.

 

Two picture, the picture on the left shows a smooth caterpillar that tapers at both ends. The picture on the right shows a caterpillar that is fuzzy all over and does not taper at either end.

Left: Diamondback moth caterpillar, showing characteristic tapering at each end. Right: Imported cabbageworm caterpillar showing characteristic fuzziness. Pictures by Maria Cramer.

We’re 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. Other materials approved for caterpillar control include Entrust/Radiant (IRAC 5), Proclaim (IRAC 6), Torac (IRAC 21A), and Exirel (IRAC 28). For Bt products and contact insecticides, coverage on the undersides the leaves is essential.

 

Tomatoes

In high tunnels and the first field plantings of tomatoes, we’re seeing limited aphid, thrips, and spider mite activity. If dealing with primarily aphids, products such as Beleaf (IRAC 29) are recommended, especially if plants have reached the flowering stage. For thrips, Entrust, Radiant (IRAC 5) and Torac (IRAC 21A) can be used. For spider mites, Nealta (IRAC 25) is an effective material that is more friendly to beneficial insects, but Portal (IRAC 21A) and other materials can be used to manage populations.

 

Please consult the Mid-Atlantic Commercial Vegetable Production Guide for a more comprehensive list of materials that are labeled for specific crops and pests. As always, be sure to follow label rates and application instructions.

Authors: Amanda Quadrel (Northern NJ Veg IPM coordinator) and Maria Cramer (Southern NJ Veg IPM coordinator)

 

Vegetable IPM Update 5/08/25

Sweet Corn

We’ve put out 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. As a reminder, we’re no longer using blacklight traps as of this year, and we’ll be reporting pheromone trap counts in the Plant Pest Advisory as the season progresses.

Cole Crops 

A shiny black beetle with straight antennae stands on a leaf surrounded by circular feeding holes.

Flea beetle surrounded by feeding damage. Picture by Maria Cramer.

Flea beetle are active in various cole crops. This year, they have been especially prevalent in Napa cabbage and bok choy. Young plants are especially vulnerable to attack from flea beetles. The treatment threshold for flea beetles in heading cole crops is 50% infestation.

 

Two picture, the picture on the left shows a smooth caterpillar that tapers at both ends. The picture on the right shows a caterpillar that is fuzzy all over and does not taper at either end.

Left: Diamondback moth caterpillar, showing characteristic tapering at each end. Right: Imported cabbageworm caterpillar showing characteristic fuzziness. Pictures by Maria Cramer.

We’re 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. Other materials approved for caterpillar control include Entrust/Radiant (IRAC 5), Proclaim (IRAC 6), Torac (IRAC 21A), and Exirel (IRAC 28). For Bt products and contact insecticides, coverage on the undersides the leaves is essential.

 

Tomatoes

In high tunnel tomatoes, we’re seeing limited aphid, thrips, and spider mite activity. If dealing with primarily aphids, products such as Beleaf (IRAC 29) are recommended, especially if plants have reached the flowering stage. For thrips, Entrust, Radiant (IRAC 5) and Torac (IRAC 21A) can be used. For spider mites, Nealta (IRAC 25) is an effective material that is more friendly to beneficial insects, but Portal (IRAC 21A) and other materials can be used to manage populations.

 

Please consult the Mid-Atlantic Commercial Vegetable Production Guide for a more comprehensive list of materials that are labeled for specific crops and pests. As always, be sure to follow label rates and application instructions.

Authors: Amanda Quadrel (Northern NJ Veg IPM coordinator) and Maria Cramer (Southern NJ Veg IPM coordinator)

 

Take a quick survey to help with Field Equipment Sanitation Research!

In a Specialty Crop Research Initiative (SCRI) grant designed to guide future solution and resources centered around field equipment sanitation, collaborative team comprising pathologists, weed scientists, agronomists, and experts in agricultural equipment sanitation has crafted a questionnaire. This questionnaire is designed to gather growers’ input on their current practices and determine the necessity for implementing new ones.

The research will develop a more comprehensive understanding of the challenges associated with field equipment sanitation and work toward developing solutions that are effective, implementable and sustainable.

To introduce the survey and forthcoming research effort, Dr. Matt Grieshop, lead PI on this project indicates that “We are a group of agricultural research and extension professionals from across the United States that are curious about grower and agricultural professional perceptions about the importance of field equipment sanitation to mitigate the spread of organisms that pose human health, weed, plant pathogen or other risks.

Agricultural field equipment includes tillage implements, tractors, harvesters, cultivation equipment, trucks, trailers, sprayers, mowers, or any other piece of equipment that is shared across fields.

This information will be solely used to help frame future research questions and outreach activities.  It will not be published or distributed in any form. Answering should take 5 minutes or less and is completely voluntary and anonymous.

Your participation is invaluable to future developments in the industry regarding food safety and equipment sanitation. We need more inputs from New Jersey specialty crops growers so that they have a say on the direction that field equipment sanitation research will take in the future!

To contribute, visit here or scan the QR code below.


If you have questions, comments or concerns contact Dr. Matt Grieshop at mgriesho@calpoly.edu or Dr. Thierry Besancon at thierry.besancon@rutgers.edu.

Early Season Tree Fruit Pest Control for 2024

  • Dormant season oil sprays
  • Dormant season copper sprays
  • Dormant season urea sprays

[Read more…]

Get ready for bagworms…NOW

Days old bagworm size

Days-old bagworm = critical management target – T. Waller – RCE

Bagworms should begin hatching NOW through – 4 weeks in NJ, beginning in the southern regions. Now is an optimal time to get this pest on your radar and prepare materials or approaches to attack first/second instar caterpillars. The control window for this pest is typically between 600-900 GDD50  when they begin to hatch and become airborne, i.e. the “ballooning” phase. It is important to check for egg-hatch prior to applications for greatest chemical efficacy, and to continue scouting as they often hatch and develop at asynchronous rates.

It is critical to target these insects EARLY!

Bagworm management – mechanical: If eggs have not hatched: hand-remove sacs/bags. Typically female/egg filled sacs are higher in the canopy so keep that in mind while scouting. This removes the problem from the field or landscape.

Treatment options for Lepidoptera (caterpillars) to have at the ready – containing: B.t. (Bacillus thuringiensis), spinosad , bifenthrin ), cyfluthrin, carbaryl, chlorantraniliprole, cyclaniliprole, cyclaniliprole + flonicamid, Lambda-cyhalothrin, cyantraniliprole, Indoxacarb.  NOTE – Lethal pesticide doses are important, as sub-lethal doses can trigger early pupation, making the pest all but invincible to chemical or biological treatments. Follow label exactly.

IT IS CRITICAL TO ROTATE MATERIALS (Rotate between IRAC groups) 

DISCLAIMER: The label is the law, always refer to it for allowable host crops, use-restrictions, application rates, reapplication intervals, re-entry intervals (REI), and mix compatibility information. Production and pesticide information on this site are for private/commercial pesticide applicators and landscape professionals only, and are NOT for home gardener use. Provided materials represent examples and do not cover all possible control scenarios. Please contact your local agent or chemical sales representative for more information or to discuss additional pest management options.

BAGWORMS (600-900 GDD) (Bagworm hatch prediction as of 5/24/23)
Crop type Common Name Scientific Name GDD Min (50F) GDD Max (95F) Reference Developmental / Target Stage
Conifer mostly, many minor hosts Bagworm Thyridopteryx ephemeraeformis 600 900 RU Larvae (early instars) – ONLY CONTROL WINDOW
Region Location Station Date (600 GDD) Date (900 GDD) *Treatment window  *Bagworm Hatch – Predictions only, SCOUTING is critical! Treat as soon as larvae detected. 
South Upper Deerfield NJ50 31-May 14-Jun 14 days
Central Howell / Freehold NJ10 9-Jun 23-Jun 14 days
North High Point NJ59 15-Jun 2-July 17 days 

Please download and print the Rutgers Nursery and Landscape Pest Scouting Guide  or  Conifer and Christmas Tree Pest Scouting Guide and refer to this post “Obtaining your local growing degree-days (GDD)” for additional information.  (See pest scouting guides for complete list of references – cited within lists below) 

Please SHARE what you SEE!! If you see a pest, disease, otherwise interesting or troublesome issue please report it to the Working Group by following the QR Code on the front of the Pest Scouting Guides or by filling out this reporting form.

Spotted lanternfly (SLF) hatch is ON in Southern and Central NJ – ALL New Jersey COUNTIES are now QUARANTINED

Spotted Lanternfly nymphs will be emerging now through the first week of May for Southern and Central New Jersey – reduce their population early in the nursery industry!

Two important notes:

  • Through conversations with nursery operators, state inspectors (NJDOA), and internal agent communications SLF hatch has begun, which indicates a critical time to knock down nymph populations with CONTACT insecticides.
  • The entire state of New Jersey is now within the SLF QUARANTINE!

More information: