GDD of Landscape Insects

Insect

Life stage

GDD50

Relevant degree day maps

Reference

American plum borer

adult flight and egg laying

245-440

250, 300, 450

1

American plum borer

2nd generation

1375-1500

1350, 1400, 1500

1

Arborvitae leafminer

larvae in mines; 1st generation

245-360

250, 300, 350

1

Arborvitae leafminer

2nd generation

533-700

500, 600, 700

1

Arborvitae leafminer

3rd generation

1700-2100

1700, 1900, 2000

1

Balsam gall midge

adults laying eggs

150-300

150, 200, 300

3

Balsam gall midge

galls apparent

550-700

550, 650, 700

3

Balsam twig aphid

egg hatch

60-100

50, 100

4

Balsam twig aphid

stem mothers present (control target)

100-140

100, 150

4

Banded ash clearwing borer

adult emergence

1800-2200

1800, 1900, 2000

1,2

Beech scale

eggs present

800

800

3

Beech scale

egg hatch; 1st crawlers

1250

1250

3

Birch leafminer

1st adult emergence

175-215

150, 200

1

Birch leafminer

Adults laying eggs

275-375

250, 300, 350

2

Birch leafminer

larvae and pupae

375-500

350, 400, 500

2

Birch leafminer

adults and egg laying; 2nd generation

600-700

600, 700

2

Black pineleaf scale

egg hatch

1068

1050

1

Bronze birch borer

adults; eggs; new grubs

400-600

400, 500, 600

1,2

Cankerworm

young caterpillars

100-200

100, 200

1

Cooley spruce gall adelgid

1st adults active - Spruce (control target)

25-120

50, 100

3

Cooley spruce gall adelgid

1st galls visible - Spruce

200-310

200, 250, 300

3

Cooley spruce gall adelgid

1st adults active - Douglas fir

90-180

100, 150

1

Cooley spruce gall adelgid

1st nymphs - Douglas fir (control target)

90-150

100, 150

3

Cooley spruce gall adelgid

2nd nymphs - Douglas fir (control target)

600-1000

600, 800, 1000

3

Cooley spruce gall adelgid

2nd adults active (control target)

1500-1600

1500, 1550, 1600

3

Cottony maple scale

adults & yellow crawlers on leaf veins

802-1200

800, 950, 1200

1,2

Dogwood borer

adults, eggs, caterpillars

350-850

350, 550, 850

1,2

Eastern pine shoot borer

1st adults active

75-200

50, 100, 200

3

Eastern spruce gall adelgid

1st adults active (control target)

25-100

50, 100

3

Eastern spruce gall adelgid

egg hatch, galls begin forming

250-310

250, 300

1,3

Eastern spruce gall adelgid

2nd adults active (control target)

1500-1600

1500, 1550, 1600

3

Eastern tent caterpillar

egg hatch

45-100

50, 100

1,2,3

Eastern tent caterpillar

tents apparent

150

150

3

Eastern tent caterpillar

pupation

450

450

3

Elm leaf beetle

1st generation

400-600

400, 500, 600

1

Elm leaf beetle

2nd generation

1300

1300

1

Elm leafminer

adult emergence

215-240

200, 250

1

Elm leafminer

1st generation larvae

365-530

350, 450, 550

2

Emerald ash borer

1st adult emergence

400-500

400, 500

3

Emerald ash borer

peak adult activity

1000-1200

1000, 1100, 1200

*

Euonymus scale

egg hatch - 1st generation

400-575

400, 500, 550

1

Euonymus scale

egg hatch - 2nd generation

1900-1050

*

1

European pine sawfly

1st larvae

100-195

100, 150, 200

1,3

European pine shoot moth

1st larvae

50-220

50, 100, 200

3

European pine shoot moth

egg hatch

900-1000

900, 950, 1000

3

European pine shoot moth

adults active

700-800

700, 750, 800

3

Fall webworm

egg hatch

850-900

850, 900

1

Fall webworm

caterpillars feeding

1200-1800

1200, 1500, 1800

2

Fall webworm

tents become apparent

1850-2050

1850, 1900, 2000

3

Fletcher scale

egg hatch

850-900

850, 900

1

Forest tent caterpillar

egg hatch

125-250

100, 150, 250

3

Forest tent caterpillar

pupation

450

450

3

Forest tent caterpillar

tachinid parasitic flies abundant

450-550

450, 500, 550

3

Forest tent caterpillar

sarcophagid parasitic flies abundant (“government fly” or “friendly fly”)

750-850

750, 800, 850

*

Golden oak scale

Egg hatch

680-700

650, 700

1

Greater peach tree borer

adult emergence

575-710

550, 650, 700

1

Gypsy moth

egg hatch, 1st larvae

145-200

150, 200

1, 3

Gypsy moth

young caterpillars

450

450

1

Gypsy moth

pupation

900-1200

900, 1000, 1200

3

Honeylocust spider mite

egg hatch

220-250

200, 250

1

Honeylocust plant bug

egg hatch

220-250

200, 250

1,3

Introduced pine sawfly

1st larvae

400-600

400, 500, 600

3

Imported willow leaf beetle

Adults active

120-275

150, 250, 300

1

Jack pine budworm

young larvae feeding

300-350

300, 350

3

Jack pine budworm

large larvae feeding - defoliation apparent

650-700

650, 700

3

Jack pine sawfly

eggs; young larvae

100-200

100, 150, 200

1

Jack pine sawfly

larger larvae consuming needles

275-500

250, 350, 500

1

Japanese beetle

adults emerge and feed

950-2150

950, 1500, 2000

1,2

Juniper scale

egg hatch

550-700

550, 600, 700

1

Larch casebearer

egg hatch

120-150

100, 150

1

Large aspen tortrix

pupation

600-700

600, 700

3

Lesser peach tree borer

adult flight

350-375

300, 350, 400

1,2

Lilac borer

adult flight

325-350

300, 350

1,2

Magnolia scale

egg hatch

1925-1950

1900, 2000

1

Mimosa webworm

egg hatch - 1st generation

850-900

850, 900

1

Northern pine weevil

1st adults active

25-100

50, 100

3

Northern pine weevil

2nd adults active

1200-1400

1200, 1300, 1400

3

Oystershell scale

egg hatch

350-500

350, 400, 500

1

Pales weevil

1st adults active

25-100

50, 100

3

Pales weevil

2nd adults active

1200-1400

1200, 1300, 1400

3

Pine chafer (Anomela beetle)

1st adults active

450-600

450, 500, 600

3

Pine engraver (Ips bark beetle)

1st adults active

100-150

100, 150

100, 150

Pine needle midge

1st adults active

400-500

400, 450, 500

3

Pine needle scale

1st generation egg hatch

250-400

250, 300, 400

1,3,5,7

Pine needle scale

1st generation - hyaline stage (control target)

400-500

400, 500

5

Pine needle scale

2nd generation egg hatch

1250-1350

1250, 1300, 1350

1,3,5

Pine needle scale

2nd generation - hyaline stage (control target)

1500

1500

5

Pine root collar weevil

1st adults active

300-350

300, 350

3

Pine root collar weevil

2nd adults active

1200-1400

1200, 1300, 1400

3

Pine shoot beetle

new adults emerge; begin shoot-feeding

500-550

500, 550

6

Pine shoot beetle

optimal control window

450-500

450, 500

6

Pine tortoise scale

egg hatch begins; 1st crawlers

400-500

400, 450, 500

3

Pine tortoise scale

egg hatch ends; last of the crawlers

1000-1200

1000, 1100, 1200

3

Pine tube moth

adults; egg laying; caterpillars

90-250

100, 200, 250

1

Red-headed pine sawfly

1st larvae

400-600

400, 500, 600

3

Spruce budscale

egg hatch, 1st crawlers

700-1150

700, 900, 1150

1,3

Spruce budworm

1st larvae

200-300

200, 250, 300

3

Spruce needleminer

1st larvae

150-200

150, 200

3

Spruce spider mite

1st egg hatch

150-175

150, 200

1,3

Striped pine scale

egg hatch

750-800

750, 800

1

Turpentine beetle

parent beetles colonizing brood material

300-350

300, 350

3

Walnut caterpillar

egg hatch; caterpillars

1600-1700

1600, 1650, 1700

1

White pine weevil

1st adults active

25-220

50, 100, 200

3

White pine weevil

2nd adults active

1200-1400

1200, 1300, 1400

3

Zimmerman pine moth

1st larvae

25-100

50, 100

7

Zimmerman pine moth

adult flight

1700

1700

1

References
1 = Herms,D.A. Using degree days and plant phenology to predict pest activity. Chapter 11. Tactics and Tools for IPM.
2 = Sadof, C.S. 1994. Recommendations for managing insects and mites on shade trees and shrubs. Purdue University, Dept. of Entomology publication E-41. West Lafayette, IN. 117 p.
3 = MSU observations
4 = Fondren, K. and D.G. McCullough. 2002. Biology and management of balsam twig aphid. MSU Extension bulletin E-2813. 4 p.
5 = Fondren, K. and D.G. McCullough. 2002. Biology and management of pine needle scale. MSU Extension bulletin E-2812. 4 p.
6 = McCullough, D.G. and C.S. Sadof. 1998. Evaluation of an integrated management and compliance program for Tomicus piniperda (Coleoptera: Scolytidae) in pine Christmas tree fields. Forum Article, Journal of Economic Entomology 91:785-795.
7 = Eliason, E.A. and D.G. McCullough. 1997. Survival and fecundity of three insects reared on four varieties of Scotch pine Christmas trees. Journal of Economic Entomology 90:1598-1608.

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