Regional alerts
Regional Pest Alert Map
What's pressuring trees across North America right now — ranked by severity, mapped to hotspots, and linked straight to treatment. A dashboard for crews planning routes and PHC programs.
Active pest pressure
66 hotspots tracked nationwide
SevereHighModerateLow
Positions are approximate and for illustration. This dashboard is fed by the Pest & Disease library — open any alert below for diagnosis and treatment.
Current alerts
14 high-priority threats active
Severe6 alerts
Severe
Asian Longhorned Beetle
Anoplophora glabripennis
Localized eradication zones in the Northeastern and Midwestern United States
Peak: Adults active and emerging July through October
Worcester, MA · Long Island / NYC, NY · Clermont County, OH
Severe
Dutch Elm Disease
Ophiostoma novo-ulmi
Throughout the native range of American elm in the United States and Canada
Peak: Symptoms appear late spring through summer; bark beetle vectors active spring–fall
Minneapolis, MN · Denver, CO · Toronto-border / Buffalo, NY
Severe
Emerald Ash Borer
Agrilus planipennis
Eastern, central, and expanding western United States and southern Canada
Peak: Adults fly and lay eggs late May through August; larvae feed under bark spring–fall
Detroit, MI (introduction epicenter) · Chicago, IL · Pittsburgh, PA
Severe
Hemlock Woolly Adelgid
Adelges tsugae
Eastern United States from the southern Appalachians to New England
Peak: Woolly masses most visible fall through spring; two generations feed Oct–June
Great Smoky Mountains, TN/NC · Shenandoah / Blue Ridge, VA · Catskills / Hudson Valley, NY
Severe
Oak Wilt
Bretziella fagacearum
Eastern and central United States; severe in the Upper Midwest and central Texas
Peak: Spring and early summer (high infection risk from fresh wounds April–July)
Austin / Texas Hill Country, TX · Minneapolis–St. Paul, MN · Madison, WI
Severe
Southern Pine Beetle (Pine Bark Beetle)
Dendroctonus frontalis
Southeastern United States, expanding north; related bark beetles range across the West
Peak: Multiple generations spring through fall; outbreaks peak in summer droughts
Atlanta / north GA · Pine Barrens, NJ · East Texas piney woods
High8 alerts
High
Armillaria Root Rot
Armillaria spp.
Throughout the United States and Canada; a widespread soilborne root pathogen
Peak: Decline visible in summer drought stress; honey mushrooms appear in fall
Seattle, WA · Sierra Nevada, CA · Asheville / southern Appalachians, NC
High
Bacterial Leaf Scorch
Xylella fastidiosa
Eastern, southeastern, and central United States (xylem-feeding insect vectors)
Peak: Symptoms most visible mid-summer to fall (July–October)
Washington, DC metro · Philadelphia, PA · Charlotte, NC
High
Bronze Birch Borer
Agrilus anxius
Northern United States and Canada, throughout the range of birches
Peak: Adults emerge and lay eggs late May through July; larvae tunnel under bark
Minneapolis, MN · Denver, CO · Chicago, IL
High
Fire Blight
Erwinia amylovora
Throughout the United States wherever rosaceous trees grow; worst in warm, humid spring weather
Peak: Bloom through early summer, during warm, wet, humid weather
Yakima Valley, WA · Kansas City, MO · Raleigh, NC
High
Spongy Moth (formerly Gypsy Moth)
Lymantria dispar
Northeastern and Great Lakes United States and eastern Canada, spreading south and west
Peak: Caterpillars feed and defoliate May–June; egg masses laid mid-summer overwinter
Hartford / central CT · Boston, MA · Grand Rapids, MI
High
Spotted Lanternfly
Lycorma delicatula
Mid-Atlantic and Northeastern United States, spreading west and south
Peak: Nymphs spring–summer; conspicuous winged adults July–November; eggs overwinter
Reading / Berks County, PA (US epicenter) · Philadelphia, PA · Newark / northern NJ
High
Thousand Cankers Disease
Geosmithia morbida (vectored by Pityophthorus juglandis)
Western United States and pockets of the East and Midwest where black walnut grows
Peak: Beetles active and galleries expand spring through fall; dieback shows in summer
Denver / Front Range, CO · Knoxville, TN · Boise, ID
High
Verticillium Wilt
Verticillium dahliae / Verticillium albo-atrum
Throughout the United States; a soilborne fungus persisting for years in soil
Peak: Symptoms appear in summer, often after heat or drought stress (June–September)
Columbus, OH · Minneapolis, MN · Portland, OR
Moderate6 alerts
Moderate
Anthracnose
Apiognomonia / Discula / Colletotrichum spp.
Throughout the United States; worst in regions with cool, wet spring weather
Peak: Spring, during cool, wet, rainy weather at and just after leaf-out
Portland, OR · Washington, DC · Nashville, TN
Moderate
Apple Scab
Venturia inaequalis
Cool, humid regions of the United States and Canada, especially the Northeast and Upper Midwest
Peak: Primary infections in cool, wet spring weather (bud break through early summer)
Hudson Valley, NY · Grand Rapids, MI · Boston, MA
Moderate
Bagworms
Thyridopteryx ephemeraeformis
Eastern and central United States, particularly the Midwest and Southeast
Peak: Larvae feed and enlarge bags June–August; bags overwinter with eggs
Kansas City, MO · St. Louis, MO · Oklahoma City, OK
Moderate
Cankerworm (Inchworm)
Alsophila pometaria / Paleacrita vernata
Eastern and central United States and southern Canada
Peak: Larvae feed and defoliate in spring (April–May) as leaves expand
Charlotte, NC · Richmond, VA · Boston, MA
Moderate
Cytospora Canker
Cytospora / Leucostoma spp.
Throughout the United States; attacks stressed, drought- or winter-injured trees
Peak: Cankers expand in spring and fall; symptoms most visible in summer dieback
Denver, CO · Salt Lake City, UT · Minneapolis, MN
Moderate
Scale Insects
Coccoidea (various species)
Throughout the United States on a wide range of trees and shrubs
Peak: Vulnerable mobile 'crawlers' emerge late spring–summer (species dependent)
Atlanta, GA · Houston, TX · Long Island, NY
Low2 alerts
Low
Aphids
Aphidoidea (various species)
Throughout the United States and Canada on a vast range of host plants
Peak: Populations build in spring and early summer, with flushes through the season
Los Angeles, CA · Dallas, TX · Columbus, OH
Low
Powdery Mildew
Erysiphe / Podosphaera / Phyllactinia spp.
Throughout the United States; favored by humid days and cool nights with poor airflow
Peak: Late spring through fall, worst in humid, shaded, crowded conditions
Atlanta, GA · Memphis, TN · Sacramento, CA
Diagnose & treat
Every alert traces back to a full diagnostic entry.
Symptoms, range, peak season, severity and treatment options — cross-linked to the tree species each pest attacks. The library is the source this map reads from.