ALERT – Boxwood Blight Infection Potential for the majority of NJ this weekend (5/13 – 5/15)!

There is a potential for new boxwood blight infections this weekend throughout much of NJ – especially southern regions. The end of week rains coupled with increased temperatures and prolonged periods of leaf wetness will contribute to the spread of boxwood blight infections.

  • It is time to begin protective fungicide applications in high value areas if you have not already done so! 

  • Protective fungicide applications should remain in effect or be initiated immediately for Boxwood Blight throughout much of NJ
  • If your area is not listed (throughout all of NJ please visit the USPEST.ORG Boxwood Blight Risk Model – CLICK HERE TO CHECK YOUR LOCAL PREDICTIONS
  • BWB has already been observed this season just south of us in Maryland.

Boxwood Blight risk-model information, considerations, and links:

Boxwood Blight Risk Assessment as of 5/10/2022
Region Location CODE 10-May 11-May 12-May 13-May 14-May 15-May NOTES
Southern Upper Deerfield NJ50 Very Low  Very Low  Very Low  Low  Infection Risk Infection Risk High probability of new infections
Central Howell / Freehold NJ10 Very Low  Very Low  Very Low  Low*  Low*  Low*  *5/13-15 very close to infection risks
Northern High Point NJ59 Very Low  Very Low  Very Low  Very Low Low*  Low*  *5/14-15 very close to infection risks
Please check your local boxwood blight risk at (https://uspest.org/risk/boxwood_app)

(CLICK on this link – input your area code – select closest weather station – check 7-14 prediction – click on graph / table)

These advisories are general in nature and change rapidly over time and throughout the state! Someone from your business should be using this risk model daily if boxwood is important to your financial stability – In 30 seconds you can have a better idea of boxwood blight (and other pathogen) activity in your immediate area! Please contact Tim Waller if you need help using this service (twaller@njaes.rutgers.edu), I want to help! 

Fungicides; 

  1. You very well may have these materials already applied as ‘cover-sprays’ – But – be mindful that protectant fungicides loose efficacy the more rain (or overhead irrigation) they are subjected to, and reapplication may be warranted.
  2. ROTATE between Fungicide Resistance Action Committee (FRAC codes) to avoid this pathogen becoming resistant to specific chemicals

Format: [FRAC code]: Chemical name (Trade names * no endorsement implied) 

  • [M05]: Chlorothalonil (Daconil WS)
  • [M05 + 1] Chlorothalonil + Thiophanate methyl (Spectro 90WDG)
  • [11] Trifloxystrobin + [7] Fluopyram  (Broadform)
  • [11] Trifloxystrobin + [3] Triadimefon (Armada 50WDG)
  • [M03] Mancozeb
  • [12] Fludioxonil (Medallion WDG)
  • [3] Tebuconazole (Torque)BW

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. Trade-names listed do not imply endorsement and are used as examples only. Please contact your local agent or chemical sales representative for more information or to discuss additional pest management options.

Resources 

Background on the pathogen: 

There will be another post pertaining to insect development tomorrow (5/12/22)

Spotted Lanternfly egg hatch is coming or here now – Critical knockdown of nymphs

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!

 

Through conversations with nursery operators, state inspectors (NJDOA), and internal agent communications four shade trees represent the vast majority of nursery stock with adult SLF eggs. This means we should be targeting these trees early – treating for nymphs as they emerge from the egg masses and before they move on to more tender hosts.

The vast majority of shade trees with egg masses in NJ are:

  1. Red maple – huge proportion
  2. Birch
  3. Willow
  4. Styrax

Generally, adults are laying eggs on these four nursery crops late summer/fall, then as the nymphs emerge (April/May) they move to more tender growth, often onto understory plants, weeds, hedge rows, roses (wild and cultivated), and tender herbaceous and perennial plants (May, June, early July). This means we have a very short window to target a large percentage of nymph emergence on these four crops with Contact Insecticides. Scout these areas for nymphs over the next few weeks, and be at the ready to treat immediately

Be ready to target nymph populations early this season with contact materials 

Once the nymphs have moved on to their favored 1st-3rd instar crops (herbaceous, perennial, roses, grapes, etc.) they will then begin to move back to these four shade trees (and other woody hosts) as 4th instars (red-coloration, mid/late July) and adults (August) that will ultimately mate and lay eggs (September/October), repeating the cycle.

Systemic materials – Generally systemics are best utilized when targeting late instars and adult populations (both born at the nursery and flying in from outside), often requiring approximately 3-4 weeks prior to anticipated insecticidal activity. In the nursery setting we may already be utilizing systemic materials to treat other insect populations, offering some level of protection from the nymphs migrating away from theses four shade trees, towards their favored feeding locations. In operations where egg masses have been abundant, treating with systemic materials, when appropriate should be considered to reduce local populations in addition to targeting nymphs with contact materials.

Penn State – Spotted Lanternfly Management Guide (click here)Contains the most complete list of labeled systemic and contact insecticides for SLF

Note – applications during bloom for specific host crops should be avoided to protect pollinators. 

 

Additional information: 

We are collectively trying to avoid crippling load-by-load phytosanitary inspections

WE as an industry are in this together, in order to safeguard our industry please do the following:

  1. SLF Training Permits for hang-tags (click here) are required for each company driver who delivers your plants out-of-state. This training is relatively simple and you can also obtain Training materials to educate your employees (click here)
  2. Scout every plant for ANY SLF life stages – from dead adults to egg masses. REMOVE life stage prior to shipment and train employees to know the various appearances of SLF egg masses. Use this guide – SLF EGG MASS GUIDE – USE FOR TRAINING (click here to download) (print and hang up / distribute to personnel)

 

Nursery Pest Updates and Scouting next two weeks – initiate Red-headed flea beetle systemics now for Central and Southern NJ

This post covers three topics:

  1. Control and timing of applications for Red-headed flea beetle (RHFB)Systemic materials should be used now to target emerging adults in May. 
    1. Please refer to this resource for timing and material selection: RHFB timeline using GDD, material selection, print-out ready (click here)
    2. Combination of resources from Danny Lauderdale (NC State), Brian Kunkel (UDel.), Tim Waller (RU)
  2. Seasonal reminders:
    1. Protectant, broad-spectrum ‘cover-sprays’ should be initiated ASAP or as plastic is removed / crops can be accessed
    2. SLF egg masses: We are all in this together should be remembered when it comes to checking loads for SLF.
      1. SLF EGG MASS GUIDE – USE FOR TRAINING (click here to download, hang up for employees)
      2. Refer to this post “Don’t let Spotted Lanternfly Impact Spring Shipping” for additional information 
  3. Pest Scouting for 100-200 Growing Degree-days (approx. next two weeks in Southern and Central NJ). 
    1. Refer to this post “Obtaining your local growing degree-days” for additional information 

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)

Increasing temperatures = scout for insects pests! 2022 Nursery and Conifer Pest Scouting Guides HERE

With the increases in daily temperature averages expected over the next week for the southern and central areas of NJ, pest scouting should commence on commercially important ornamental crops and landscapes. Typically, in our region, growing degree-days (GDD50) are counted beginning March 1st (known as a biofix date), however this year by March first we may see degree-day accumulation approaching 20+. Therefor scouting efforts should be commenced, especially in conifers. 

We have compiled the GDD resources into one single document – please download and print multiple copies of this for yourself and employees in efforts to best scout for these insect pests. These guides do not dictate when to spray, rather they inform scouting ranges for insect pests, vulnerable life-stages, and overlapping timeframes for multiple troublesome pests.

Download here:

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

Conifer Pest Scouting Guide 2022 PDF

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

We will be making regular announcements throughout the season, however we wanted you to have this beta-version of the compiled growing-degree day information. This will be updated and modified throughout the season – PLEASE let me know what difference you are seeing in the field so we can continue to make this resource better for all of us.   

Contact: twaller@njaes.rutgers.edu (or call the Cumberland County Extension Office – 856-451-2800)

Growing degree-days as of writing this (using USPEST.org weather station codes):

  • Southern (NJ50): 13
  • Central (NJ10): 13
  • Northeastern (Greater NYC Metro area (D6302) and Northwestern (NJ59): 0

Crop type

Common Name

Scientific Name

GDD Min (50F)

GDD Max (95F)

Reference

Developmental / Target Stage

Conifer
Conifer rust mites
Eriophyidae
7
22
4
Overwintering eggs hatch
Pomes, Stone fruit
European red mite
Panonychus ulmi
7
58
2
1st adults active
Conifer
White pine weevil
Pissodes strobi
7
58
RU
Overwintering adults become active / prevent egg laying
Deciduous
Oystershell scale
Lepidosaphes ulmi
7
91
2
Spring control of overwintering stage
Deciduous, Yew
Cottony camellia / taxus scale
Pulvinaria floccifera
7
91
5
Spring control of overwintering stage
Many
Southern red mite
Oligonychus ilicis
7
91
5
Overwintering eggs hatch
Conifer
Taxus mealybug
Dysmicoccus wistariae
7
91
2
Spring control of overwintering stage
Oaks
Kermes oak scales
Kermes spp.
7
91
2
Spring control of overwintering stage
Conifer
Elongate hemlock scale
Fiorinia externa
7
120
2
Spring control of overwintering stage
Many
Aphids
Aphidoidea
7
120
2
Spring control of overwintering stage
Conifer
Spruce spider mite
Oligonychus ununguis
7
121
RU
Overwintering eggs hatch
Oaks
Golden oak scale
Asterolecanium variolosum
7
121
5
Spring control of overwintering stage
Conifer
Pales weevil
Hylobius pales
7
121
RU
Overwintering adults become active / prevent egg laying
Magnoliaceae
Tuliptree scale
Toumeyella liriodendri
12
121
2
Spring control of overwintering stage
Rhododendron, Azalea
Azalea lacebug
Stephanitis pyrioides
18
372
RU
Spring control of overwintering stage
White and Scotch Pine
White pine aphid
Cinara strobi
22
91
RU
Spring control of overwintering stage
Conifer
Pine bark adelgid
Pineus strobi
22
58
2
Spring control of overwintering stage
Magnoliaceae
Magnolia scale
Neolecanium cornuparvum
22
91
2
Spring control of overwintering stage
Conifer
Spruce bud scale
Physokermes piceae
22
120
2
Spring control of overwintering stage
Conifer
Juniper scale
Carulaspis juniperi
22
148
2
Spring control of overwintering stage