Cucurbit downy mildew forecasting website up and running for 2021

For cucurbit growers who have been using the CDMpipe website the past few years to track the progress of cucurbit downy mildew in the US, a new website was relaunched for the 2020 growing season. Anyone can visit the new website by clicking here. Please take the quick survey to help our colleagues out! To receive alerts please click on the Alerts tab at the top of the page!

Early Season Conifer and Christmas Tree Pest Scouting List Using Growing Degree-days (base 50F)

Please print or download the two resources of this post (click on them)

The information provided in the downloads gives early season scouting ranges (in growing degree days, base 50F) for specific insect pests harming conifer and Christmas tree production and maintenance. Additionally, forecasting predictions (GDD50 accumulation) for calendar dates of multiple regions of New Jersey (S,N,C) are provided.

To determine your local growing degree-days, please review this postObtaining your local growing degree-day information”

Scouting Ranges:

  • This document supports scouting, it does not replace it. Keeping good notes on pest development will help dial in scouting and treatment efforts at your local level.
  • It is important to note that these GDD50 are not exact, rather provide a range of GDD and subsequent calendar dates that can be used to scout for, and treat for, insect pests.
  • The pests listed here will be listed again in future scouting range announcements as they undergo further developmental life stages or are vulnerable to management options.
  • If you need more information, OR you are regularly seeing specific pest development stages at growing degree-days different than those listed here, please contact Tim Waller at twaller@njaes.rutgers.edu

 

Projected GDD50 accumulation as of
NJ Region Location March 1st April 1st May 1st June 1st July 1st
Southern Upper Deerfield (NJ50) 0 24 133 540 1217
Central Howell / Freehold (NJ10) 0 14 95 443 1064
Northern High Point (NJ59) 0 1 7 220 672
Forecast: NOAA NCEP Coupled Forecast System model version 2 (CFSv2) forecast system (3.5 months) (USPEST.ORG)

 

Early Season Conifer Pest Scouting – Growing Degree-day Ranges Starting (0-300 GDD50)
Common Name Scientific Name GDD Min (50F) GDD Max (95F) Reference Developmental / Target Stage
Conifer rust mites Eriophyidae 7 22 4 Overwintering eggs hatch
Eastern pine weevil Pissodes nemorensis 7 58 RU Overwintering adults become active / prevent egg laying
Taxus mealybug Dysmicoccus wistariae 7 91 2 Spring control of overwintering stage
Cottony taxus scale Pulvinaria floccifera 7 91 6 Spring control of overwintering stage
Elongate hemlock scale Fiorinia externa 7 120 2 Spring control of overwintering stage
Spruce spider mite Oligonychus ununguis 7 121 RU Overwintering eggs hatch
Pales weevil Hylobius pales 7 121 RU Overwintering adults become active / prevent egg laying
White pine aphid Cinara strobi 22 91 RU Spring control of overwintering stage
Pine bark adelgid Pineus strobi 22 58 2 Spring control of overwintering stage
Spruce bud scale Physokermes piceae 22 120 2 Spring control of overwintering stage
Juniper scale Carulaspis juniperi 22 148 2 Spring control of overwintering stage
Eastern spruce gall adelgid Adelges abietis 25 100 3 spring control of overwintering stage
Northern pine weevil Pissodes approximatus 25 100 4 1st adults active
Zimmerman pine moth Dioryctria zimmermani 25 100 3 1st larvae active
Cooley spruce gall adelgid Adelges cooleyi 25 120 3 Spring control of overwintering stage
White pine weevil Pissodes strobi 25 220 4 1st adults active
European pine sawfly Neodiprion sertifer 35 145 1 Spring control of overwintering stage
Fletcher scale Parthenolecanium fletcheri 35 148 2 Spring control of overwintering stage
European pine shoot moth / borer Rhyacionia buoiana 50 220 4 1st larvae active
Pine tortoise scale Toumeyela parvicornis 58 148 2 Cralwer activity
Pine bark adelgid Pineus strobi 58 618 2 Spring control of overwintering stage
Balsam twig aphid Mindarus abietinus 60 100 4 Egg hatch
Eastern pine shoot borer Eucosma gloriola 75 200 4 1st adults active
Cooley spruce gall adelgid Adelges cooleyi 90 180 4 1st adults active – Douglas fir
Balsam twig aphid Mindarus abietinus 100 150 4 Stem mothers present (control target)
Pine engraver (Ips bark beetle) Ips spp. 100 150 4 1st adults active
European pine sawfly Neodiprion sertifer 100 195 4 1st larvae active
Larch casebearer Coleophora laricella 120 150 4 Egg hatch
Nantucket pine tip moth Rhyacionia frustrana 121 448 RU 1st generation egg hatch
Gypsy moth Lymantria dispar 145 200 4 Egg hatch, 1st larvae
Spruce spider mite Oligonychus ununguis 150 175 4 1st egg hatch
Spruce needleminer Endothenia albolineana 150 200 4 1st larvae active
Balsam gall midge Paradiplosis tumifex 150 300 4 Adults laying eggs
Spruce budworm Choristoneura fumiferana 200 300 4 1st larvae active
Cooley spruce gall adelgid Adelges cooleyi 200 310 4 1st galls visible – Spruce
Arborvitae leafminer Argyresthia thuiella 245 360 4 Larvae in mines; 1st generation
Eastern spruce gall adelgid Adelges abietis 250 310 4 Egg hatch, galls begin forming
Pine needle scale Chionaspis pinifoliae 298 448 4 1st generation egg hatch
Pine root collar weevil Hylobius radicis 300 350 4 1st adults active
Turpentine beetle Dendroctonus terebrans 300 350 4 Parent beetles colonizing brood material
References RU Rutgers Cooperative Extension – IPM Notes
2 http://ccetompkins.org/resources/using-growing-degree-days-for-insect-management
3 https://www.canr.msu.edu/ipm/agriculture/christmas_trees/gdd_of_conifer_insects
4 https://extension.psu.edu/ipm-basics-for-christmas-trees#section-2
5 https://www.agriculture.nh.gov/publications-forms/documents/landscape-pests.pdf
6 https://extension.umd.edu/ipm/pest-predictive-calendar-landscapenursery

(Please note: we will be providing pest GDD ranges regularly throughout the season for our green industries)

 

Important notes about growing degree-day models:

  1. These models do not replace scoutingThey should guide scouting efforts and pest management programs, once the vulnerable life stage or economic threshold of a pest is recorded. Observations at a local level for specific pests is critical to IPM efforts and further refinement of degree-day-based predictions.
  2. GDD50 values for pest development are not exact, rather they should be viewed as a range. 
  3. The growing degree-day model (GDD50) is general by design. Some insect pests have specific formulas for their growth and development (some examples here). However, the GDD50 model is useful for many pests and plant species.
  4. Many GDD50 target values were developed in other parts of the country and should be ‘ground truthed’ at a local level. Blind applications of pesticides, without truthing pest development, may not deliver desired outcomes.

 

Obtaining your local Growing Degree-day information

Why use local growing degree-day models?

  1. You need to know local growing degree-day accumulation values to use pest scouting/management target lists like this. 
  2. Timing is everything in pest management! Degree-day models allow us to predict when to scout for pests and when to target vulnerable life stages of pest development.
  3. Growing degree-days (GDD50) refer to the of accumulation heating units, which are the average air temperature over a 24h period minus the minimum temperature threshold. To be considered a ‘growing’ degree-day, the minimum (or base) temperature threshold is 50°F.
  4. GDD50 can be used to determine when pest life stage events such as egg hatch, adult emergence, crawler activity, adult flight, and others are likely to occur.
  5. Many times plant and insect developmental stages coincide, thus Plant Phenological Indicators can be utilized to accurately scout for pests.
  6. Luckily, we do not need to manually enter or track this data due to the availability of FREE online tools.

Important notes about growing degree-day models:

  1. These models do not replace scouting. They should guide scouting efforts and pest management programs, once the vulnerable life stage or economic threshold of a pest is recorded. Observations at a local level for specific pests is critical to IPM efforts and further refinement of degree-day-based predictions.
  2. GDD50 values for pest development are not exact, rather they should be viewed as a range
  3. The growing degree-day model (GDD50) is general by design. Some insect pests have specific formulas for their growth and development (some examples here). However, the GDD50 model is useful for many pests and plant species.
  4. Many GDD50 target values were developed in other parts of the country and should be ‘ground truthed at a local level. Blind applications of pesticides, without truthing pest development, may not deliver desired outcomes.

Two examples of degree-day calculators with instructions:

USPEST.org (home page) delivers a wide variety of degree-day, climatic, and risk-based modeling tools for various applications in agriculture. This resource also has a number of important disease predictive tools such as the Boxwood Blight Risk Model. The USPEST growing degree-day application allows for day-to-day monitoring as well as historical and predictive data. The following directions seem complicated but after a few attempts, it is easy to become proficient with this incredibly powerful modeling system. Remember BASE TEMP MUST = 50°F (for all models to be considered a ‘growing’ degree-day model)

Table 1. Uspest.org – Degree-day / Phenology Model – quick reference guide
Step # Tab Sub-category Instructions Notes
Intro Educational Detailed instructions
1 Station Search bar Enter – area code, town, or weather station code example zip code: 08302
Drop-down menu Select – location of interest example: NJ50 = Upper Deerfield
2 Model Model Category Select – all models
Model Select – degree-day calculator (general purpose) Many interesting degree-day calculators are available
Calculation Method Select – Simple average/growing dds  Average air temperature over 24 hours minus lower (base) temperature threshold
Lower Input – 50 ℉  50℉ : lower threshold must be used for ‘growing’ degree-day predictions/charts
Upper Input – 95 ℉ 95℉ : often used as upper temperature threshold value
Dates Select – date range Can be current, past, or future date ranges
Options Optional* – modify forecast type Default forecasting model: NMME (North American Multi-Model Ensemble)
3 Output Model Output Select – show full table (daily GDD accumulation) ‘DDs cumu’ = accumulated degree-days from selected start date
4 Graph Graph No action required Graphical display of current year, forecasts, and previous years based on ‘Dates’ selected
Link: https://uspest.org/dd/model_app

 

NEWA (homepage). Cornell University in cooperation with twenty-eight other groups and universities (including Rutgers) coordinate NEWA. NEWA contains a wide variety of robust degree-day models, climatic information and maps, and risk-based modeling tools for various applications in multitude crop systems. This resource also has a number of very useful, disease specific, predictive / monitoring / management tools for fruit, row, and vegetable crop diseases in addition to their growing degree-day model  (limited forecasting).

  • NEWA growing degree-day model instructions: State: select a state in the USA; Weather Station = find a local station from the list or click on the map; Degree-day type = Degree Days – Base 50. Then select the time range you wish to view. Once completed press Get Report. The results will display current and a 5-day forecast.

Informative resources: 

Please contact Tim Waller – Cumberland Co. Extension (Nursery Agent) if you need assistance setting up and using these powerful tools. (twaller@njaes.rutgers.edu)

New cucurbit downy mildew forecasting website up and running for 2020

For cucurbit growers who have been using the CDMpipe website the past few years to track the progress of cucurbit downy mildew in the US, a new website has been relaunched for the 2020 growing season. Importantly, for those you have signed up in the past you should be receiving an email in the near future asking you to sign up for the new website. You can visit the new website by clicking here. Click on the Alerts tab at the top of the page and fill out the form to receive alerts!