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: