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 |
