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Degree Days for Common Landscape Insect Pests

Ash Borer Degree Days

  • 1st instar larvae = 275-500 DD50

Ash Plantbug Degree Days

  • Nymphs = 100-200 DD50

Birch Leafminer Degree Days

  • 1st generation larvae = 275-500 DD50

Black Vine Weevil Degree Days

  • 1st generation adults = 400-600 DD50
  • 2nd generation adults = 900-1000 DD50

Bronze Birch Borer Degree Days

  • Larvae = 400-500 DD50

Cooley Spruce Gall Adelgid Degree Days

  • Adults = 50-100 DD50
  • Egg hatch = 210 DD50
  • Galls forming = 250 DD50
  • 2nd generation nymphs = 2800-3000 DD50

Cottony Maple Scale Degree Days

  • Egg hatch = 850 DD50
  • Crawlers = 900-1200 DD50

Eastern Spruce Gall Adelgid Degree Days

  • Adults = 50-100 DD50
  • Egg hatch = 90 DD50
  • 1st instar larvae = 100 DD50
  • 2nd generation nymphs = 2800-3000 DD50

Eastern Tent Caterpillar Degree Days

  • Egg hatch = 50 DD50
  • 1st instar larvae = 100 DD50
  • 2nd instar larvae = 140 DD50
  • 3rd instar larvae = 350 DD50
  • Adults = 725 DD50

Elm Leaf Beetle Degree Days

  • Larvae = 400-500 DD50

Elm Sawfly Degree Days

  • Larvae = 365 DD50

Euonymous Scale Degree Days

  • Crawlers = 500-700 DD50

European Pine Sawfly Degree Days

  • 1st instar larvae = 50-100 DD50

European Pine Shoot Moth Degree Days

  • Spring larvae active = 50-100 DD50
  • Adults = 900 DD50
  • Egg hatch = 200-100 DD50

Fall Webworm Degree Days

  • Larvae = 850 DD50

Fletcher Scale Degree Days

  • Adults = 100-200 DD50
  • Egg hatch = 600 DD50
  • Crawlers active = 900-1200 DD50

Gypsy Moth Degree Days

  • Egg hatch = 100-200 DD50
  • Larvae = 200-350 DD50

Hawthorn Leafminer Degree Days

  • Larvae = 275-500 DD50

Honeylocust Plantbugs Degree Days

  • 100-200 DD50

Imported Willow Leaf Beetle Degree Days

  • 200-350 DD50

Japanese Beetle Degree Days

  • Adults = 900-1200 DD50

Mountain Ash Sawfly Degree Days

  • 500 DD50

Oystershell Scale (brown race) Degree Days

  • Egg hatch = 265 DD50
  • 1st generation crawlers = 275-500 DD50
  • 2nd generation crawlers = 1600-1700 DD50

Oystershell Scale (grey race) Degree Days

  • 1st generation crawlers = 400-600 DD50

Pine Needle Scale Degree Days

  • 1st generation crawlers = 200-350 DD50
  • 2nd generation crawlers = 1600-1700 DD50

Pine Spittlebug Degree Days

  • 1st generation egg hatch = 145 DD50
  • 2nd generation egg hatch = 1500 DD50
  • 2nd generation crawlers = 1500-1600 DD50

Spruce Spider Mite Degree Days

  • 100-200 DD50

Taxus Mealybug Degree Days

  • 275-500 DD50

Viburnum Crown Borer Degree Days

  • 1st instar larvae = 500-600 DD50

Zimmerman Pine Shoot Moth Degree Days

  • 1st generation larvae (1st instar) = 100 DD50
  • 2nd generation larvae (1st instar) = 2700-2900 DD50

Additional Images

Author: Karen Delahaut, UW-Madison Fresh Market Vegetable Program
Revised:  8/13/2012
Item number:  XHT1088


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