Search Results for: corn borer

May 24, 2022 Tim Waller

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

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

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

February 15, 2021 Steven K. Rettke

Pest Notes: Witches’ Brooms, Pitch Mass Borers and Ants

WITCHES’ BROOMS: The development of witches’ brooms on woody plants and the resulting formation of abnormal growth can cause curiosity and concern to your clients. Typically, the new growth is distorted, and a proliferation of leaves or fruit/cones closely clumped together appears when apical dominance is lost. Witches’ Brooms are created on plants when the transfer of growth hormones is disrupted (perhaps caused from the introduction of a foreign substance). Insects (e.g., aphids), fungi, bacteria, viruses, phytoplasmas, and herbicides have all been implicated in causing the formation of witches’ brooms in many plant species.

Witches’ Brooms are plants having stunted foliage & short stem internodes. (Photo Credit: Steven K. Rettke, Rutgers Coop. Ext.)

January 18, 2017 Joe Ingerson-Mahar

Corn Earworm Developing Resistance to Bt Toxins in Sweet Corn

Corn earworm caterpillar feeding on sweet corn tassel

New research from the University of Maryland indicates that corn earworm, also known as tomato fruitworm, has developed resistance to the Cry1 Bt toxins present in some sweet corn hybrids. Based upon Galen Dively’s twenty-one years of research comparing non-Bt sweet corn varieties with Bt varieties in plot studies, the proportion of damaged ears in Bt varieties has dramatically increased over that time.

Syngenta sweet corn hybrids with Attribute® technology expressing Cry1 Ab toxins in 1996 showed less than 10% ear damage. Those hybrids with Attribute® in 2016 averaged 84% ear damage. Similarly, the amount of damaged area per ear had tripled.

Seminis produced sweet corn hybrids with Performance Series^TMcontaining Cry1 A.105 and Cry2 ab for worm control. When some of these hybrids were first evaluated in 2010 they provided 100% control of fall armyworm and 95% control of corn earworm. In 2016, six plantings at research farm sites of these hybrids averaged 67% damaged ears.

[Read more…]

Filed Under: Vegetable Crops Tagged With: corn earworm, sweet corn

Sweet Corn IPM Field Guide for NJ

Rutgers Cooperative Extension
Kris Holmstrom,
Vegetable IPM Program Associate,
Rutgers NJAES

Sampling Method: 10 samples per field, random area. Sample 5 consecutive plants for a total of 50 plants.

Seedling Stage

PEST	THRESHOLD	NOTES
Flea Beetle	6+/100 seedlings if no soil insecticide used.	Observe from an upright position so as not to disturb these pests.
Fall Armyworm	>/= 12% of plants infested.	Check for ragged injury, droppings, and live fall armyworms.

Whorl-Tassel Stage

PEST	THRESHOLD	NOTES
European Corn Borer	>/= 12% of plants infested.	Check leaves for “shot-hole” type feeding signs. Check emerging tassels for live European corn borers.
Fall Armyworm	>/= 12% of plants infested.	Check leaves for ragged-hole type feeding signs. Check inside whorl for droppings and larvae.
Leaf Rust	Presence	Check for pustules.
Northern Corn Leaf Blight	Presence @ whorl; presence >3 sample sites @ pre-tassel/tassel.	Check for lesions.
Sap Beetles	Note: presence may require frequency adjustment to silk spray program.	Check emerging tassels for sap beetles.
Corn Leaf Aphid	>/= 12% of plants infested; may require specific insecticide during silk spray program.	Check emerging tassels for aphid.

Silk Stage

PEST	THRESHOLD	NOTES
Corn Earworm	Apply insecticides at interval prescribed by local blacklight trap catches.	See local blacklight trap information guide spray schedule in the Plant & Pest Advisory Vegetable IPM Updates.
Two-spotted Spider Mite	Presence at >1 site.	Check for colonies on underside of leaves.
Japanese Beetles	~10% or more plants with beetles feeding on silks.	Check for presence on emerging silks.

[Download PDF Version]

July 24, 2026 Amanda Quadrel and Maria Cramer

Vegetable IPM Update 7/24/26

Greetings from the Veg IPM team! Read more for the latest pest and disease updates.