South Jersey RC&D Council, Inc.

Growing Degree Day (GDD) information

Rutgers Cooperative Extension of Ocean County

New Jersey Agricultural Experiment Station

From: Pest Recommendations, Ithaca, NY: Average Temperature and dates by Dr. Orton.

Key insect Control Timing by Growing Degree Day (GDD - 50 degree base), Plant Phenology Indicator (PPI) and Calendar

Pest Susceptible Month GDD PPI in Bloom

Lifestage Active

• European Pine Sawfly larvae April 100-200 Star Magnolia
• White Pine Aphid nymph April 121-246 Pussywillow
• Spruce White imm. A/M 192-250 Redbud, Saucer Mag.
• Birch Leafminer imm. early May 190-290 Redbud, B.Locust
• Tent Cat. larvae early May 150-303 Redbud, Sau. Mag.
• Gypsy Moth larvae early May 90-448 Redbud, Shadblow
• Dogwood borer adult late May 148-700 Redbud
• Azalea Lacebug nyp. mid May 248-618 Redbud
• Holy leaf miner imm. mid may 246-448 Redbud
• Privet Thrips all mid May 192-618 Redbud
• European Pine Sawfly lar. mid May 246-1388 Redbud, Magnolia
• Rhododendron borer adult late May 192-298 Redbud
• Aphids all late May 250-2800 Redbud
• Oystershell scale crawler late May 363-707 B. Locust
• Rhod. Stem Borer adult late May 298-400 B. Locust
• Boxwood Psyllid nyp. late May 290-440 B. Locust
• Elmleaf Btle adult,larv. late May 363-912 B. Locust,Weigela
• Spider mite imm. late May 363-818 B. Locust,hydrangea
• Texas mealeybug all late May 226-718 B. Locust,lilac
• Lilac borer moth late May 300-450 B. Locust, lilac
• Pine bark adelgid imm. late May 58-618 B. Locust
• Pine needle scale craw. late May 258-408 B. Locust,spiraca
• Willow leaf btle. adult late May 192-448 B. Locust
• Black vine weevil adult Jn 400-800 Kousa dogwd,beautybrush
• Bronze birch borer ad Jn 420-700 Bridalwreath,spiraea,BeaBsh
• Euonymus scale crw. Jn 533-650 Kousa dogwd,hawthrone
• Boxwood leafminer imm. Jn 448-700 Kousa dgwd, hawthrone
• Azalea lace bug larvae Jn 448-618 Kousa dgwd, beautybush
• Greenstriped mapleworm lar. Jn 533-1645 Kousa dgwd, BeaBsh
• Oak skeletonizer adult Jn 448-707 Kosua dgwd, beautybush
• Peach tree borer adult Jn 500-600 beautybush,spiraea
• Rhodo borer adult Jn 533-707 Kosua dgwd,beautybush
• Bagworm larvae Jn 600-900 Mt. Laural,mockorange
• Leaf hopper all Jn 618-802 Mt. Laural
• White prunicola scale craw. Jn 707-1151 Mt. Laural
• Mimosa webworm lar. Jn 900-1200 Yucca,catalpa
• Cottony maplescale craw. Jn 802-1265 Mt. Laural,yucca
• Privet thripes imm. Jn 1029-1266 Spiraea
• Jap. beetle adult Jn 1029-2154 Golden raintree,abelia
• Fall webworm larvae Jy 1266-1795 Golden raintree,abelia
• Spider mites all Jn 1300-2000 Golden raintree,abelia
• Jap. weevil adult Jy 1644-2271 Butterfly bush, clethra
• Nantucket pinetip moth A Jy 1514-1917 as above
• Pine needle scale (2nd) craw Jy 1388-1917 as above
• Cooley spruce gall adelgid (on Doug Fir) Aug-sept 1500-1775 hydranga, witchhazel
• Magnolia scale craw Aug 2155-2800 Mt. Ash
• Spruce spider mite (2nd) all Aug 2375-2906 Golden rod
• Locust borer adult Aug 2271-2805 Golden rod

GDD Insect Stage

• 25 White pine weevil adult
• 50 Spruce spider mite hatch
• 35 Eastern Tent cat hatch
• 40 Euonymus scale adult
• 50 European pine sawfly hatch
• 86 Birch leaf miner adult
• 116 Southern red mite hatch
• 125 Honeylocust plant bug nymphs
• 150 Gypsy moth egg hatch
• 150 Hemlock wooly adelgid 10% hatch
• 200 Honeylocust plant bug adult
• 200 Azalea white fly adult 1st gen
• 250 Boxwood leaf miner adult emergence
• 250 Boxwood psyllid nymph
• 250 Pineneedle scale crawler
• 260 Lilac ash borer adult in trap
• 260 Birch leaf miner larvae
• 350 Hemlock wooly adelgid 50% hatch
• 400 Euonymus scale crawler
• 400 Elmleaf beetle larvae 1st gen.
• 400 Elongate hemlock scale crawler
• 430 Black vine weevil adult
• 500 Greater peach tree borer adult
• 570 Arborvitae leaf miner adult
• 600 Rhododendron borer adult
• 645 Bagworm hatch
• 690 Japanese beetle adult
• 700 Cottony Texas scale crawler
• 700 Fall web worm larvae 1st gen.
• 700 Gypsy moth 2-3 cm. caterpillars
• 700 Juniper scale crawlers
• 735 Fletcher scale crawlers
• 800 Elm leaf beetle larvae 2nd gen.
• 825 European pine shoot moth adult
• 850 Azalea bark scale crawler
• 880 Mimosa webworm larvae
• 1250 Locust Leafminer adult 2nd gen.
• 1700 Euonymus scale crawler 2nd gen.
• 1800 Dogwood sawfly larvae
• 200 Tulip tree scale crawler
• 2300 Fiorinia scale crawler
• 2513 Beech scale crawler

Please call your local Rutgers Extension office for additional help in determining insect and its control