Rutgers Cooperative Extension
In this edition:
Please click “read more” below to get updates on pests, diseases, and other important resources for the week of 5/15/2023.
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.
Insect Pests
| Projected GDD50 accumulation as of 4/25/2023 (these change throughout the season!) | ||||||
| Region | Location | 25-Apr | 1-May | 1-Jun | 1-Jul | 1-Aug |
| Southern | Upper Deerfield (NJ50) | 251 | 281 | 682 | 1370 | 2218 |
| Central | Howell / Freehold (NJ10) | 188 | 207 | 537 | 1160 | 1957 |
| Northern | High Point (NJ59) | 142 | 143 | 371 | 864 | 1507 |
| Forecast: 7-month NMME based seasonal climate forecast (USPEST.ORG) | ||||||
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.
Please continue reading for much more detailed and important information!
The Rutgers Organic Grower Advisory meeting will be held on March 7th. This meeting has served to increase communication between commercial farms using organic practices and Rutgers Cooperative Extension agricultural agents and specialists. This year the meeting will be held both in-person and online. We have a AV system that will allow for better sound quality for all participants. Please see details below, and use the Qualtrics link to register if you plan to attend.
March 7th 10:00 – 2:00
Rutgers Cooperative Extension of Mercer County
1440 Parkside Avenue, Ewing NJ 08638
OR Online via Zoom
In-person attendees will have a pizza lunch option at a cost of $5.00 per person, payable at the door.
Registration deadline is March 3rd, register here!
Examples of hot topics for discussion from the 2021 Organic Grower Advisory meeting are:
• Weed control updates
• Organic animal feed
• Allium leaf miner
• Spotted lanternfly
• Organic sweet corn
• Disease control
• Organic certifications
by Katarzyna Madalinska and Anne L. Nielsen
Adult SLF are moving into vineyards from the surrounding landscape. The number of SLF on each vine varies greatly within each vineyard and locations in the state. In most vineyards in NJ and PA there is a strong border effect with numbers highest along the outside rows. However, the orientation and shape of your vineyard influences border effects. SLF are actively feeding on grapevines and will continue to feed for 1-2 months. Most SLF are in the upper canopy and as the grapes start to store carbohydrates for the winter, SLF will move down the vine, eventually feeding at the base of the vine. Research suggests that feeding by adult SLF may harm primary bud formation the following season and reduce winter hardiness. There is not a specific treatment threshold, but a good rule of thumb is 10 SLF per vine. Movement into the vineyards will continue for several weeks so multiple insecticide applications may be needed.
Treatment at this time of year is of course complicated by pre-harvest intervals (PHI) for each insecticide and grape variety. It is important to remember that SLF will feed on vines post-harvest. There are several effective insecticides available with pre-harvest intervals and residual activity (Table 1). When treating vines pre-harvest, dead SLF are commonly observed in the clusters. Post-harvest, insecticides such as Danitol or Brigade/Bifenture/bifenthrin have the longest residual activity and are expected to reduce feeding.
There are several reasons to manage adult SLF in September and October during peak movement.
Table 1. Effectiveness of Insecticides Against Spotted Lanternfly Adults. Modified recommendations from Leach et al. Crop Protection 2019 v. 24 DOI:10.1016/j.cropro.2019.05.027
| Trade name | Active ingredient | SLF Activity | Rate per acre | Seasonal Allowance | Residual Activity | PHI
(days) |
REI
(hrs) |
Labeled for SLF? |
| Mustang Maxx 0.8EC | cypermethrin | Good | 4 oz | 24 oz | <3 | 1 | 12 | Yes, 2(ee) |
| Scorpion 35SL | dinotefuran | Excellent | 5 oz. | 20.9 oz | <7 | 1 | 12 | Yes, 2(ee) |
| Actara 25WDG | thiamethoxam | Excellent | 3.5 oz | 7.0 oz | <14 | 5 | 12 | Yes, 2(ee) |
| Carbaryl 4L | carbaryl | Excellent | 1-2 qt | 10 qt | 7 | 7 | 12 | No |
| Avaunt 30DG | indoxicarb | Fair | 6 oz | 12 oz | 7 | 7 | 12 | Yes, 2(ee) |
| Danitol 2.4EC | fenpropathrin | Excellent | 16-21.33 oz | 42.66 oz | >26 | 21 | 24 | Yes, 2(ee) |
| Brigade 2EC | bifenthrin | Excellent | 3.2-6.4 oz. | 6.4 oz | 21 | 30 | 12 | Yes, 2(ee) |
There are several reasons to manage adult SLF in September and October during peak movement.
By Katarzyna Madalinska and Anne Nielsen
New Jersey is currently in its 5th year of invasion from spotted lanternfly. Populations are now widespread throughout the state and have established in almost every county in NJ. SLF pressure is variable throughout NJ’s counties, and we do not currently have a threshold for management of nymphs.
1st instar SLF in NJ vineyard – photo by K. Madalinska
SLF nymphs are hatching throughout the state and will continue to do so in the coming weeks. Despite seeing nymphs within the vineyard, we do not recommend immediate treatment at this time. Hatch will occur over a multiple week period depending on the site of egg masses and exposure. The early instars feed on new growth, particularly the underside of leaves and shoots. At this point there is no evidence that early instar feeding results in plant injury or yield loss. Peak abundance of SLF nymphs in vineyards is during their 1st to 2nd instars approximately and 2-3 weeks after the first hatch. Management during their 2nd instar will target the highest number of individuals and prevent additional treatments against nymphs. This timing typically coincides with other key pests within the vineyard, such as grape berry moth and Japanese beetle. Many broad-spectrum insecticide options for grape berry moth or Japanese beetle will also effectively kill SLF nymphs (see table) and insecticides against SLF will not be needed until the adult stage.
| Trade name | Active ingredient | Class | Rate per acre | Seasonal Allowance | SLF* | GBM | JB |
| Brigade 2EC | bifenthrin | Pyrethroid | 3.2-6.4 oz | 6.4 oz | E* | E | |
| Actara | thiamethoxam | Neonicotinoid | 3.5 oz | 7.0 oz | E* | G | |
| Assail 30SG | acetamiprid | Neonicotinoid | 2.5-5.3 oz | 2 times | G | G | F |
| Carbaryl 4L | carbaryl | Carbamate | 1-2 qt | 10 qt | E | G | G |
| Avaunt | indoxicarb | Oxadiazine | 6 oz | 12 oz. | E* | G | G |
| Danitol 2.4EC | fenpropathrin | Pyrethroid | 16-21.33 oz | 42.66 oz | E* | E | E |
| Belay | clothianidin | Neonicotinoid | 2.0–6.0 oz. | 12 oz. | G | G | G |
| BaythroidXL | cyfluthrin | Pyrethroid | 1.6-3.2 oz | 12.8 oz | E | E |
Always consult the label for further instructions.
*2(ee) approved for SLF in NJ grapes
E = excellent control
G = good control
F = fair control
This post covers three topics:
Growing degree-days as 4/12/22 (~Next two weeks)
| Projected GDD50 accumulation as of 4/13/2022 | 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-Apr | 1-May | 1-Jun | |
| South | Upper Deerfield | NJ50 | 116 | 236 | 660 | |
| Central | Howell / Freehold | NJ10 | 114 | 200 | 553 | |
| North | High Point | NJ59 | 35 | 67 | 313 | |
| Forecast: NOAA NCEP Coupled Forecast System model version 2 (CFSv2) forecast system (3.5 months) (USPEST.ORG) | ||||||
| Crop type | Common Name | Scientific Name | GDD Min (50F) | GDD Max (95F) | Reference | Developmental / Target Stage |
| Conifer | Pine engraver (Ips bark beetle) | Ips spp. | 100 | 150 | 4 | 1st adults active |
| Conifer | Balsam twig aphid | Mindarus abietinus | 100 | 150 | 4 | Stem mothers present (control target) |
| Conifer | European pine sawfly | Neodiprion sertifer | 100 | 195 | 4 | 1st larvae active |
| Andromeda | Andromeda lace bug | Stephanitis takeyai | 115 | 279 | RU | Nymphs (1st generation) |
| Azalea | Azalea lace bug | Stephanitis pyrioides | 118 | 372 | RU | Nymphs (1st generation) |
| Conifer | Larch casebearer | Coleophora laricella | 120 | 150 | 4 | Egg hatch |
| Elm, Service berry | Woolly elm aphid | Eriosoma americana | 121 | 246 | 2 (6) | Control target |
| Birch | Birch leafminer | Fenusa pusilla | 123 | 290 | RU | Adults – egg laying |
| Many | Gypsy moth | Lymantria dispar | 145 | 200 | 4 | Egg hatch, 1st larvae |
| Holly | Holly leaf miner | Phytomyza ilicis | 147 | 265 | RU | Adults – egg laying |
| Many | Cankerworms, inch-worms, loopers | (many) | 148 | 290 | 2 | Larvae treatment |
| Yews, Rhododendrons, many | Black Vine Weevil | Otiorhynchus sulcatus | 148 | 400 | 2 | Pupation / Adult emergence |
| Lilac, ash, privet, many | Lilac / Ash Borer | Podosesia syringae | 148 | 299 | 2 | Adult flight |
| Dogwood, many | Dogwood Borer | Synanthedon scitula | 148 | 700 | 2 | Adult activity |
| Conifer | Hemlock woolly adelgid | Adelges tsugae | 150 | 150 | RU | Eggs and 10% hatch |
| Conifer | Spruce needleminer | Endothenia albolineana | 150 | 200 | 4 | 1st larvae active |
| Conifer | Spruce spider mite | Oligonychus ununguis | 150 | 175 | 4 | 1st egg hatch |
| Conifer | Balsam gall midge | Paradiplosis tumifex | 150 | 300 | 4 | Adults laying eggs |
| Witchhazel, River birch | Spiny witchhazel gall aphid | Hamamelistes spinosus | 171 | – | 6 | Control target |
| Birch | Birch Leafminer | Fenusa pusilla | 175 | 215 | 4 | 1st adults active |
| Birch | Birch leafminer | Fenusa pusilla | 190 | 290 | RU | Larvae (1st generation) |
| Conifer | Spruce spider mite | Oligonychus ununguis | 190 | 363 | RU | Immatures/Adults |
| Rhododendron | Rhododendron gall midge | Clinodiplosis rhododendri | 192 | 363 | RU | Larvae |
| Honeylocust | Honeylocust pod gall midge | Dasineura gleditchiae | 192 | 229 | RU | Larvae |
| Privet | Privet thrips | Dendrothrips ornatus | 192 | 618 | 2 | Typical treatment window |
| Holly | *Native holly leafminer | Phytomyza ilicicola | 192 | 298 | 2 | Egg hatch |
| Holly | Holly leafminer | Phytomyza ilicis | 192 | 290 | RU | Egg hatch |
| Willows, Cottonwood, Poplar | Imported willow leaf beetle | Plagiodera versicolora | 192 | 448 | RU | Larvae/Adults |
| Larch | Larch sawfly | Pristophora erichsonii | 192 | 299 | 2 | Typical treatment window |
| Andromeda | Andromeda lacebug | Stephanitis takeyai | 192 | 303 | RU | Adults |
| Rhododendron | Rhododendron borer | Synanthedon rhododendri | 192 | 298 | 2 | Typical treatment window |
| Conifer | Cooley spruce gall adelgid | Adelges cooleyi | 200 | 310 | 4 | 1st galls visible – Spruce |
| Spruce | Spruce budworm | Choristoneura fumiferana | 200 | 300 | 5 | Larvae |
| Conifer | Douglas fir needle midge | Contarinia pseudotsugae | 200 | 400 | 3 | Adults emerge from soil |
| Lilac, ash, privet, many | Lilac / Ash Borer | Podosesia syringae | 200 | 299 | RU | Adults – 1st Treatment |
| References | RU | Rutgers Cooperative Extension – Landscape IPM Notes | ||||
| Daily GDD50 = (Max + Min temp.) / 2 – 50 (min temp. threshold) (Simple average growing degree-day, min. 50F, max 95F) | 2 | http://ccetompkins.org/resources/using-growing-degree-days-for-insect-management | ||||
| 3 | https://extension.psu.edu/ipm-basics-for-christmas-trees#section-2 | |||||
| 4 | https://www.canr.msu.edu/ipm/agriculture/christmas_trees/gdd_of_conifer_insects | |||||
| 5 | https://www.agriculture.nh.gov/publications-forms/documents/landscape-pests.pdf | |||||
| 6 | https://extension.umd.edu/ipm/pest-predictive-calendar-landscapenursery | |||||
| 7 | https://www.canr.msu.edu/ipm/agriculture/christmas_trees/gdd_of_landscape_insects | |||||
| Unv. Del. | Coorespondance with Dr. Kunkel (University of Delaware)-evolving GDD ranges | |||||
| Compiled by – Timothy J. Waller, Ph.D. – Rutgers Cooperative Extension, Cumberland County Nursery Crops – twaller@njaes.rutgers.edu | ||||||
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)
