NURSERY PEST SCOUTING GUIDE – August (1300-2200 GDD50)
Please download and print the pest scouting guide resource (printable version of the information below for your desk or truck) –(click on the link and then print):
- Pest Scouting Guide August 2021 (1600-300 GDD50 )
- To determine your local growing degree-days, please review this post “Obtaining your local growing degree-day information”
| Projected GDD50 accumulation as of 8/4/2021 | ||||||
| Region | Location | 1-Aug | 1-Sep | 1-Oct | 1-Nov | – |
| Southern | Upper Deerfield (NJ50) | 2145 | 2931 | 3477 | 3682 | – |
| Central | Howell / Freehold (NJ10) | 1896 | 2630 | 3109 | 3249 | – |
| Northern | High Point (NJ59) | 1490 | 2045 | 2352 | 2384 | – |
| Forecast: NOAA NCEP Coupled Forecast System model version 2 (CFSv2) forecast system (3.5 months) (USPEST.ORG) | ||||||
(Same material as downloads)
| Pest Scouting – Growing Degree-day Ranges | (1600-3000 GDD50) | |||||
| CROP TYPE | Common Name | Scientific Name | GDD Min (50F) | GDD Max (95F) | Reference | Developmental / Target Stage |
| Many | Redheaded flea beetle | Systena frontalis | 1570 | 1860 | Udel. | 2nd generation egg hatch |
| Many | Two-banded Japanese weevil | Pseudocneorhinus bifasciatus | 1644 | 2271 | RU | Adults |
| Willow | Willow twig aphids | Lachnus spp. | 1644 | 2271 | 5 | Typical treatment window |
| Conifer | Juniper webworm | Dichomeris marginella | 1645 | 1917 | RU | Larvae Treatment |
| Euonymus | Euonymus Scale | Unaspis euonymil | 1700 | – | RU | Prophylactic 2nd generation treatments |
| Conifer | Cryptomeria scale | Aspidiotus cryptomeriae | 1750 | 2130 | RU, 4 | Crawlers emerge (2nd generation) |
| Many | Obscure scale | Melanaspis obscura | 1774 | – | 6 | Egg hatch / crawler |
| Oaks | Oak skeletonizer | Bucculatrix ainsliella | 1798 | 2155 | RU | Larvae |
| Conifer | Arborvitae leafminer | Argyresthia thuiella | 1800 | 2200 | RU | Larvae Treatment (3rd generation) |
| Mimosa, Honeylocust | Mimosa webworm | Homadaula anisocentra | 1800 | 2100 | RU | Larvae (2nd generation) |
| Conifer | Cooley spruce gall adelgid | Adelges cooleyi | 1850 | 1950 | RU | Galls open (Spruce) |
| Many | Redheaded flea beetle | Systena frontalis | 1878 | 2318 | Udel. | 2nd generation Adults feeding |
| Turf | Hairy chinch bug | Blissus leucopterus | 1903 | 2160 | RU | Second generation- 50%- 2nd instars |
| Tulip | Tuliptree aphid | Illinoia liriodendri | 1917 | 2033 | RU | Nymphs |
| Conifer | Zimmerman pine moth | Dioryctria zimmermani | 1917 | 2154 | 5 | Treatment window (adult flight-1700 GDD) |
| Mainly Oaks | Orangestriped oakworm | Anisota senatoria | 1917 | – | 6 | Egg hatch – early instars |
| Conifer | White pine aphid | Cinara strobi | 1991 | 2271 | RU | Adults |
| Rhododendron | Azalea whitefly | Pealius azaleae | 2032 | 2150 | 5 | Adults/nymphs (3rd generation) |
| Maple | Sugar maple borer | Glycobius speciosus | 2032 | 2375 | 5 | Typical treatment window |
| Conifer | Maskell scale | lepidosaphes pallia | 2035 | – | 6 | Egg hatch / crawler (2nd generation) |
| Mainly Tulip | Tulip tree scale | Toumeyella liriodendri | 2037 | 2629 | RU | Crawlers (1st generation) |
| Mainly Magnolia | Magnolia scale | Neolecanium cornuparvum | 2155 | 2800 | RU | Crawlers (1st generation) |
| Euonymus | Euonymus Scale | Unaspis euonymil | 2235 | – | 6 | Egg hatch / crawler (2nd generation) |
| Locust | Locust borer | Magacyllene robiniae | 2271 | 2805 | 5 | Typical treatment window |
| Poplar and Willow | Poplar and willow borer | Crytorhynchus lapathi | 2271 | 2806 | 5 | Typical treatment window |
| Conifer | Spruce spider mite | Oligonychus ununguis | 2375 | 2806 | 5 | Typical treatment window – fall activity |
| Many | Southern red mite | Oligonychus ilicis | 2500 | 2700 | 5 | Typical treatment window |
| Maple | Japanese maple scale | Lopholeucaspis japonica | 2508 | – | 6 | Egg hatch / crawler (2nd generation) |
| Yew, many conifers | Fletcher Scale (Yew) | Parthenolecanium fletcheri | 2515 | 2800 | RU | Fall control of overwintering stage |
| Conifer | Elongate hemlock scale | Fiorinia externa | 2515 | 2625 | RU | Typical treatment window – fall activity |
| Hardwoods | Fall webworm | Hyphantria cunea | 2793 | – | 6 | Egg hatch / crawler (2nd generation) |
| Conifer | Cooley spruce gall adelgid | Adelges cooleyi | 2800 | 3000 | 3 | Fall control of overwintering stage |
| Conifer | Eastern spruce gall adelgid | Adelges abietis | 2800 | 3000 | 3 | Fall control of overwintering stage |
| 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. | References | RU | Rutgers Cooperative Extension – Landscape IPM Notes | |||
| 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 | |||||
| Daily GDD50 = (Max + Min temp.) / 2 – 50 (min temp. threshold) | 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 8-04-2021 – Timothy J. Waller, Ph.D. – Rutgers Cooperative Extension, Cumberland County Nursery Crops – twaller@njaes.rutgers.edu | ||||||
Redheaded flea beetle considerations:
Adults should be surfacing any day in the southern regions of the state. However, in two sentinel plot locations I have yet to see second generation adults as of 8/3/2021.
Contact materials aimed at managing developing larvae (especially growth regulators) may be particularly useful at this time. Contact materials or fast acting systemics should be used to target adults in the next few days to weeks. The use of long lasting systemics should also be considered to protect foliage from the next generations adults (if a third generation occurs) and again late season to guard from first generation adults in the 2022 spring season.
These GDD estimates and corresponding calendars are evolving as we continue to learn more about this pest. If you have high populations please contact Tim Waller so we can continue to adapt our recommendations in NJ. Email: twaller@njaes.rutgers.edu
SURVEY REQUESTS
WE NEED A FEW MORE FARMS!! Please answer a few questions if you would like to be included in a statewide Phytophthora in Conifer Nurseries sampling project
Contact – Timothy J. Waller – twaller@njaes.rutgers.edu for more information
