GDD - Calendar

COLLEGE OF FOOD, AGRICULTURAL,
AND ENVIRONMENTAL SCIENCES

The Ohio State Phenology Calendar

Species

Phenological Event

GDD

White Pine Weevil - Pissodes strobi adult emergence 84 Eastern Tent Caterpillar - Malacosoma americanum egg hatch 92 Larch Casebearer - Coleophora laricella larval feeding begins 128 Black stem borer - Xylosandrus germanus first adult emergence 136 European Pine Sawfly - Neodiprion sertifer egg hatch 144 Inkberry Leafminer - Phytozyma agricola adult emergence 150 Smooth Crabgrass - Digitaria ischaemum first seedling emergence 155 Spruce Spider Mite - Oligonychus ununguis egg hatch 162 Boxwood Psyllid - Cacopsylla buxi egg hatch 179 Spongy moth - Lymantria dispar egg hatch 192 Spotted lanternfly - Lycorma delicatula egg hatch & first nymph (predicted) 200 Azalea Lace Bug - Stephanitis pyrioides egg hatch 206 Viburnum Leaf Beetle - Pyrrhalta viburni first egg hatch 210 Large Crabgrass - Digitaria sanguinalis first seedling emergence 211 Birch Leafminer - Fenusa pusilla adult emergence 215 Elm Leafminer - Fenusa ulmi adult emergence 219 Alder Leafminer - Fenus dohrnii adult emergence 224 Honeylocust Spider Mite - Platytetranychus multidigituli egg hatch 227 Honeylocust Plant Bug - Blepharidopterus chlorionis egg hatch 230 Hawthorn Lace Bug - Corythucha cydoniae adult emergence 253 Hawthorn Leafminer - Profenusa canadensis adult emergence 260 Smooth Crabgrass - Digitaria ischaemum 25% seedling emergence 263 Imported Willow Leaf Beetle - Plagiodera versicolora adult emergence 274 Pine Needle Scale - Chionaspis pinifoliae egg hatch - 1st generation 305 Cooley Spruce Gall Adelgid - Adelges cooleyi egg hatch 308 Eastern Spruce Gall Adelgid - Adelges abietis egg hatch 308 Lilac Borer - Podosesia syringae adult emergence 330 Smooth Crabgrass - Digitaria ischaemum 50% seedling emergence 354 Spotted lanternfly - Lycorma delicatula peak nymph emergence (predicted) 355 Lesser Peach Tree Borer - Synanthedon pictipes adult emergence 372 Holly Leafminer - Phytomyza ilicicola adult emergence 375 Euonymus Scale - Unaspis euonymi egg hatch - 1st generation 406 Locust Leafminer - Odontota dorsalis adult emergence 437 Boxwood Leafminer - Monarthropalpus flavus adult emergence 440 Large Crabgrass - Digitaria sanguinalis 25% seedling emergence 472 Oystershell Scale - Lepidosaphes ulmi egg hatch 497 Bronze Birch Borer - Agrilus anxius adult emergence 547 Smooth Crabgrass - Digitaria ischaemum 80% seedling emergence 548 Emerald Ash Borer - Agrilus planipennis adult emergence 550 Black Vine Weevil - Otiorhynchus sulcatus adult emergence 560 Potato Leafhopper - Empoasca fabae adult arrival 568 Juniper Scale - Carulaspis juniperi egg hatch 571 Twospotted Spider Mite - Tetranychus urticae egg hatch 627 Bagworm - Thyridopteryx ephemeraeformis egg hatch 630 Large Crabgrass - Digitaria sanguinalis 50% seedling emergence 692 Fletcher Scale - Parthenolecanium fletcheri egg hatch - 1st generation 730 Calico Scale - Eulecanium cerasorum egg hatch 748 European Fruit Lecanium Scale - Parthenolecanium corni egg hatch 767 Greater Peach Tree Borer - Synanthedon exitiosa adult emergence 775 Striped Pine Scale - Toumeyella pini egg hatch 783 Rhododendron Borer - Synanthedon rhododendriÂ adult emergence 815 Dogwood Borer - Synanthedon scitula adult emergence 830 Cottony Maple Scale - Pulvinaria innumerabilis egg hatch 851 Fall Webworm - Hyphantria cunea egg hatch 867 Mimosa Webworm - Homadaula anisocentra egg hatch - 1st generation 874 Asian longhorned beetle - Anoplophora glabripennis first adult emergence 887 Winged Euonymus Scale - Lepidosaphes yanagicola egg hatch 892 Spruce Budscale - Physokermes piceae egg hatch 894 Azalea Bark Scale - Acanthococcus azaleae egg hatch 957 Japanese Beetle - Popillia japonica adult emergence 970 Emerald ash borer - Agrilus planipennis 50% adult emergence 1000 Spotted lanternfly - Lycorma delicatula adult emergence (predicted) 1160 Large Crabgrass - Digitaria sanguinalis 80% seedling emergence 1160 Pine Needle Scale - Chionaspis pinifoliae egg hatch - 2nd generation 1349 Wooster - Ctrl-F to search the page 7/18/2025 12:08:59 AM 1,537 Spotted lanternfly - Lycorma delicatula peak adult emergence (predicted) 1584 Asian longhorned beetle - Anoplophora glabripennis 50% adult emergence 1887 Mimosa Webworm - Homadaula anisocentra egg hatch - 2nd generation 1920 Euonymus Scale - Unaspis euonymi egg hatch - 2nd generation 1923 Magnolia Scale - Neolecanium cornuparvumÂ egg hatch 1938 Banded Ash Clearwing Borer - Podosesia aureocincta adult emergence 2195

Denise Ellsworth
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Phone: 330-263-3723 | ellsworth.2@osu.edu

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