borer — Plant & Pest Advisory

March 31, 2025 Tim Waller and William Errickson

Register for the NEW – 2025 Ornamental IPM Program PLUS Boxwood Blight, Pest emergence, Updates

Ornamental IPM 2025 v1 flyer

Please consider signing up for the NEW 2025 – Rutgers Ornamental IPM Program.

The focus of this program is to provide timely updates on pest, disease, and weeds impacting commercial ornamental producers. The webinars will focus on the most important pests for a 2 week interval, will be recorded, and will be shared shortly thereafter with Spanish overdub (spoken word). The trap packages are in an effort to find grower led solutions for monitoring economically important pests throughout the multiple regions of New Jersey. Please consider joining this program for its inaugural year.

Registration includes:

Site visit to your ornamental nursery/farm from Rutgers agents
Delivered printed IPM resources (Guides, factsheets, bulletins)
Free pheromone & sticky trap kit + guidance on setup/monitoring
Access to live bi-weekly webinars (Zoom)
(First session NEXT TUESDAY 4/8 @ 12PM)
Every Second and Fourth, Tuesday, April through September
Webinars will be recorded – posted later with Spanish overdub

This program is free, however registration is required.

click here to Register

Boxwood Blight Risk Assessment as of 3/4/2025
Region	Location	CODE	31-March	1-April	2-April	3-April	4-April	5-April
Southern	Upper Deerfield	NJ50	Very Low	Very Low	Very Low	Low	Minor Risk	Very Low
Central	Howell / Freehold	NJ10	Minor Risk	Very Low	Very Low	Low	Minor Risk	Very Low
Northern	Wantage	NJ79	Low	Very Low	Very Low	Low	Risk	Very Low
			M	T	W	TH	F	S
Please check YOUR LOCAL risk (click here)

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)

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.

Keep reading for more resources!

May 20, 2024 Tim Waller

Nursery Update 5/20/24 – Red-headed flea beetle and flathead borer ADULT emergence, Boxwood blight, bagworms, more

Please note: The Rutgers Nursery and Green Industry Working Group is working to deliver regular pest and disease updates throughout the season. These will be in addition to important alerts, critical topics, and pesticide credit opportunities. This tool is made for you, the commercial agriculture business, so please let us know if there are particular topics you would like to see included in the regular update.

Email: twaller@njaes.rutgers.edu Phone: 856-451-2800 Ext. 1.

Projected GDD50 accumulation as of 5/20/2024 (for June – July)
CODE	Location	20-May	1-Jun	15-Jun	1-Jul	15-Jul
NJ50	Upper Deerfield (South)	437	658	957	1363	1766
NJ73	Vineland (South)	454	670	961	1360	1755
KMIV	Millville Airport (South)	445	655	942	1338	1730
NJ05	Greenwich (South)	453	681	984	1395	1798
NJ10	Howell (Central)	344	545	809	1180	1554
N59	High Point (North)	275	463	683	997	1316
USPEST.ORG – Model: simple average/growing degree-day, Min: 50F – Max: 95F, NMME forecast
Forecast: 7-month NMME based seasonal climate forecast (USPEST.ORG) – Subject to change regularly = Check Often

Keep reading for more ALERTS – Red-headed flea beetle and Borer ADULT EMERGENCE, Boxwood Blight, bagworms [Read more…]

Filed Under: Landscape, Nursery, & Turf, Nursery Tagged With: 2024 Nursery, bagworm, borer, boxwood, boxwood blight, boxwood blight risk model, bronze birch borer, emerald ash borer, emergence, IPM, IPM Observations, Nursery IPM, red headed flea beetle, redheaded flea beetle, scale, scale insects

June 14, 2023 Tim Waller, William Errickson and Steven K. Rettke

Nursery Pest and Disease Update 6/15/2023

In this edition:

Insects:
- MORE Scale crawlers emerging
- Borers
- Beetles
Diseases:
- Oomycete root diseases (Phytophthora, Pythium, Phytopythium)
- Leaf spots / foliage diseases
- Boxwood Blight – reminder
- Virus observations
Nutrient Management
- Managing Soluble Salts by monitoring EC
- Plant Tissue analysis
Plant Spotlight:
- American Holly (Ilex opaca)
Cumberland Nursery / NJNLA – Twilight: tonight (6/15) for NURSERYMEN ONLY (contact twaller@njaes.rutgers.edu or 856-451-2800 Ext. 1. for details)

Please click “read more” below to get updates on pests, diseases, and other important resources for the week of 6/15/2023.

May 24, 2022 Tim Waller

Nursery Pests Scouting June – Bagworms, Scales, Borers, RHFB, BWB

Red-headed flea beetle – Adult emergence beginning any day now

Please refer to this timeline of pest development compiled by Tim Waller in communication with Brain Kunkel (Unv. Del) and Danny Lauderdale (NC State)

Contains material selection and timing, along with regime information and considerations

Boxwood Blight Alert – Infection Potential (Saturday) 5/27

Boxwood Blight Risk Assessment as of 5/24/2022
Region	Location	CODE	24-May	25-May	26-May	27-May	28-May	29-May
Southern	Upper Deerfield	NJ50	Very Low	Very Low	Low	High Risk	Very Low	Very Low
Central	Howell / Freehold	NJ10	Very Low	Very Low	Low	Infection Risk	Very Low	Very Low
Northern	High Point	NJ59	Very Low	Very Low	Very Low	Infection Risk	Very Low	Low
Check local boxwood blight risk here (CLICK HERE – input your area code – select closest weather station – check 7-14 prediction – click on graph / table)

Refer to the most recent Alert for more information – CLICK HERE

Pest Scouting – Please refer to these documents for a full listing of insects pests for your area corresponding to growing degree-days (GDDs).

Nursery and Landscape Pest Scouting Guide 2022 PDF (note this contains conifer pests as well)
Conifer Pest Scouting Guide 2022 PDF

Contact if seeing insects at different times: twaller@njaes.rutgers.edu (or call the Cumberland County Extension Office – 856-451-2800)

The following key groups of pests will be active, vulnerable, or otherwise treatable during the next month throughout most of NJ. Here, bagworms, scale insects and borers with key life stage events during the 350-1500 GDD timeframe are discussed. Note there are many other insect pests present this time of year so please view the pest scouting guides above for your particular needs.

Projected GDD50 accumulation as of 5/24/2022 (USPEST)						Note: Growing degree-day values utilize daily average air temperatures with a minimum temperature threshold (a.k.a. ‘base’) of 50F = GDD50 (max. temp. threshold set at 95F). These values are accumulated from a biofix date, such as January or March 1st in the NE USA. Provided GDD50 are scouting ranges and should be truthed.
Region	Location	Station	24-May	1-Jun	1-Jul
South	Upper Deerfield	NJ50	488	638	1358
Central	Howell / Freehold	NJ10	426	551	1203
North	High Point	NJ59	288	387	909
Forecast: NOAA NCEP Coupled Forecast System model version 2 (CFSv2) forecast system (3.5 months) (USPEST.ORG)

Refer to this post “Obtaining your local growing degree-days” for additional information

BAGWORMS (600-900 GDD) (Bagworm hatch prediction as of 5/24/22 – now until July 14 (Southern NJ (NJ50)))

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

Larvae (early instars) –

ONLY CONTROL WINDOW

Refer to this post for additional information on Bagworms

BORER Insect Activity for 350 – 1500 GDD (Now until ~July 1 in Southern NJ (NJ50))
Crop type	Common Name	Scientific Name	GDD Min (50F)	GDD Max (95F)	Reference	Developmental / Target Stage
Malus, Prunus, many	Lesser peach tree borer	Synanthedon pictipes	350	375	4	Adult flight, egg laying
Dogwood, apple, pecan, elm, hickory, willow	Dogwood borer	Synanthedon scitula	350	850	4	adults, eggs, caterpillars
Birch	Bronze Birch Borer	Agrilus anxius	440	880	RU	Adults (egg laying)
Malus, Prunus, many	Peach Tree Borer	Synanthedon sp.	500	600	RU	Adults – emerge (1st treatment both types)
Rhododendron	Rhododendron borer	Synanthedon rhododendri	509	696	RU	Adults emerge
Malus, Prunus, many	Greater peach tree borer	Synanthedon exitiosa	575	710	4	Adult emergence
Many	Roundheaded appletree borer	Saperda candida	802	1129	RU	Adults
Ash	Emerald ash borer	Agrilus planipennis	1000	1200	4	Peak adult activity
Malus, Prunus, many	Peachtree borer	Synanthedon sp.	1500	1800	RU	Larvae Treatment
Many	Roundheaded apple tree borer	Saperda candida	1514	1798	5	Typical treatment window
Conifer	Nantucket tip moth	Rhyacionia frustrana	1514	1917	RU	Adults 2nd generation

Click here – “Identifying Clearwing Moth Borers in Pheromone Traps” or “Differentiating the Common Wood Borers of Ash Trees”

May 13, 2022 Tim Waller

Pest Scouting 200-500 GDD – Get sprayers ready for Borers, Scale Crawlers, and other important pests

It’s that time of year again, many scale crawlers and borers will be active over the next few weeks throughout NJ. Be prepared to target specific pest life-stages for the highest level of efficacy per material cost and get those problem insects in check. Application of contact insecticides during specific activity windows for these pests should be coupled with systemic applications now to help protect woody plants later on.

Borers attack stressed plants. If you recently dug then heeled-in trees, transplanted seedlings, or otherwise seriously stressed a tree, please consider taking immediate action to protect them from both adult flights (contact trunk sprays) and future infestations (systemics)

Please Download these resources: (The scouting guide is for you to print and keep on hand…these are just updates)

Nursery and Landscape Pest Scouting Guide 2022 PDF (note this contains conifer pests as well)

Conifer Pest Scouting Guide 2022 PDF

Contact if seeing insects at different times: twaller@njaes.rutgers.edu (or call the Cumberland County Extension Office – 856-451-2800)

Projected GDD50 accumulation as of 5/13/2022						Note: Growing degree-day values utilize daily average air temperatures with a minimum temperature threshold (a.k.a. ‘base’) of 50F = GDD50 (max. temp. threshold set at 95F). These values are accumulated from a biofix date, such as January or March 1st in the NE USA. Provided GDD50 are scouting ranges and should be truthed.
Region	Location	Station	13-May	1-Jun	1-Jul
South	Upper Deerfield	NJ50	297	603	1323
Central	Howell / Freehold	NJ10	242	508	1160
North	High Point	NJ59	135	345	867
Forecast: NOAA NCEP Coupled Forecast System model version 2 (CFSv2) forecast system (3.5 months) (USPEST.ORG)

Refer to this post “Obtaining your local growing degree-days” for additional information

June 18, 2015 Richard Buckley

Borer Mania

Cryptomeria samples have been coming into the Plant Diagnostic Laboratory with increasing frequency this spring. Their issues with winter damage, particularly this year, have been chronicled on this blog. We’ve also had a couple of samples diagnosed with Maskell scale in the lab this spring, too. Pretty routine set of samples, just a few more than usual, until last week that is… [Read more…]

Filed Under: Landscape, Nursery, & Turf, Plant Diagnostic Lab Tagged With: borer