National Snapshot

The wool comes out of hiding — and the map gets bigger

Two stories this week. First, hemlock woolly adelgid scouting season opens: as temperatures cool, the white woolly masses become visible at needle bases again, and Michigan's newest detections (Manistee and Van Buren counties) put its infested-county count at eleven — a reminder that the front is still moving. Second, this bulletin now covers six regions: the new South-Central & Plains card brings Texas through the Dakotas on board (details below). Meanwhile SLF egg-scraping season continues, mushroom mapping is in full swing, and oak pruning opens in about two weeks.

Sap feeder

Hemlock woolly adelgid wool becomes visible as temps cool (see the featured pest) — check needle bases on the undersides of outer branch tips, and note Michigan's footprint has grown to 11 counties. Fall oil and systemic windows are open.

Invasive

SLF egg masses keep accumulating through first hard frost — scrape into alcohol, inspect vehicles and staged materials, and report finds in Connecticut's request counties (Windham, Tolland, Litchfield) and anywhere west of the known front.

Mite

Spruce spider mite remains in its cool-season window on spruce, arborvitae, juniper, and hemlock — tap-test before writing off bronzing as summer damage, and fold mite checks into your HWA scouting.

Borer

Twig girdlers continue raining cut twigs (rake and destroy); banded ash clearwing still triggering false EAB calls — round holes and pupal skins mean clearwing. Fall EAB injection window stays open while soil moisture supports uptake.

Disease

Mushroom mapping continues — Armillaria clusters and Ganoderma conks are free diagnostics; the below-ground read (plus a fall-planting root-ball check) is in the Soil-Borne Watch. Leaf-drop sanitation season starts: rake tar spot and scab leaves out of circulation.

Planning

Two weeks to oak pruning: October opens the safe window in the North. Fall fertilization, root-zone work, dormant-oil bookings, and fall planting are all live now.

Methodology Note

How we report growing degree days

Growing degree days accumulate from January 1 and only climb through the season. Each region's reading is anchored to the latest measured cooperative-extension station data (base 50°F), so figures track real, on-the-ground heat rather than the calendar. Because published station data can lag by a week or two, always confirm against your nearest local station (NEWA, Enviroweather, or your state tool) before timing an application.

Pest on the Chart · This Week

Hemlock Woolly Adelgid

Adelges tsugae

This week's pest on the chart, because its camouflage just expired. Hemlock woolly adelgid spends the summer as nearly invisible dormant nymphs — but as temperatures cool, the insects resume feeding and secrete the white, cottony wool that gives them away, parked at the base of needles on the undersides of branch tips. Left alone, HWA kills eastern and Carolina hemlock in roughly 4–10 years by draining stored starches at the needle bases. The front is still expanding: Michigan's newest confirmations in Manistee and Van Buren counties bring its active-infestation count to eleven counties, and fall is when new-county finds get made — usually by someone who flipped a branch tip over.

Scout

Now – Spring

Hosts

Hemlock

Rx Note

Flip the tips

℞ — Scout by flipping outer branch tips: white woolly balls at the needle bases (not on the needles themselves) are diagnostic, most visible fall through spring. Treat infested hemlocks with thorough-coverage horticultural oil in the fall window, or go systemic for large and high-value trees — imidacloprid soil application (slow, multi-year protection) or dinotefuran basal-bark spray (fast uptake, pairs well as a rescue) — following state restrictions near water. Prioritize hemlocks shading streams and foundations plantings, note any Laricobius biocontrol release areas before spraying, and report finds in new counties or townships to your state program: fall reports are how the map stays honest.

Regional Alert

Fall Front Watch

No new quarantine orders verified this week — but two invasion fronts are exactly where fall fieldwork makes the difference.

Michigan

HWA footprint grows to 11 counties — MDARD's confirmations in Manistee and Van Buren counties extend the Lake Michigan shoreline corridor (joining Allegan, Antrim, Benzie, Leelanau, Mason, Muskegon, Oceana, Ottawa, and Washtenaw). Fall wool makes detection possible — operators statewide should flip hemlock branch tips and report suspects to MDARD/DNR.

SLF Line

Egg-mass season is containment season — masses accumulate through first hard frost on bark, stone, and anything staged outdoors. Connecticut requests reports for Windham, Tolland, and Litchfield; the Iowa front remains report-immediately territory. The standing districts — laurel wilt (Suffolk Co., NY), oak wilt (Finger Lakes, NY), box tree moth (8 MD + 3 NJ counties, OH federal zone) — all hold with no new counties this week.

℞ Fall finds redraw maps. Wool on a hemlock tip or a fresh egg mass on a trailer is how new counties get caught early — photograph, report, and keep host material local.

Soil-Borne Disease Watch

Map What Fruits, Check What You Plant

Two below-ground jobs this week: keep logging the fruiting bodies, and don't let fall planting import next decade's root disease.

Fruiting Now

Armillaria & Ganoderma — honey-colored mushroom clusters at drought-stressed bases confirm summer's collapses; fresh varnish-shelf conks at the flare flag structural decay for risk assessment before winter storms. Photograph, map, and pair with a collar check for mycelial fans — the conk starts the conversation, sounding and inspection finish it.

Fall Planting

Inspect before the hole closes — planting season is also Phytophthora-import season: reject stock with dark, sloughing feeder roots, sour-smelling root balls, or girdling roots at the flare; set root flares high, and never replant a woody species into an unexcavated Armillaria hole. On known-wet ground, fix drainage and grade now — phosphite stays protective-only for high-value neighbors.

Flagging

Verticillium wrap-up — one-sided flagging on maple, redbud, and magnolia stays visible until leaf drop — confirm with sapwood streaking and a lab culture now, while symptomatic tissue is easy to sample, and replant only with non-hosts.

℞ The fall root file pays twice. Every mushroom photo, root-ball rejection, and drainage fix logged now becomes next season's risk, removal, and replant proposals — below-ground cause, above-ground evidence.

New This Week

A sixth region joins the report: South-Central & Plains

Starting this issue, readers in TX, OK, AR, LA, KS, NE, SD, ND, and NM get a card of their own — oak wilt country, the EAB southern front, pecan pests, and Plains shelterbelts finally have a home. Two tidy-ups come with it: Kentucky now rides with the Southeast and Wyoming with the West, so every state in the lower 48 (plus DC) is on a card. New-zone readers: hit reply and tell us what you're seeing in the field — it sharpens your card.

Regional Rx · 6 Zones

Read your zone like a chart

Each card reports the region's growing-degree-day reading (the vital sign that drives every timing call), what's active now (Diagnose), and how to time treatment (℞). GDD ranges are typical for the week, base 50°F from Jan 1 — always confirm against your nearest station.

NE

Northeast & New England

ME · NH · VT · MA · RI · CT · NY

GDD · Accumulated

~2,350–2,750

0

1,500

3,000+

Conditions: Accumulation nearly flat as nights cool; drought recovery remains the fall priority. Laurel wilt (Suffolk Co.) and oak wilt (Finger Lakes) districts stand; CT requests SLF reports for Windham, Tolland, and Litchfield.

Diagnose · Active Now

•

Hemlock woolly adelgid wool becoming visible — flip branch tips on every hemlock; HWA remains a top Northeast killer.

•

SLF egg masses accumulating on bark, stone, and equipment; spruce spider mite active on conifers.

•

Fall needle shed on white pine and arborvitae driving calls — inner needles only, seasonal.

•

Twig girdlers dropping oak and hickory twigs; Armillaria mushrooms fruiting at drought-stressed bases.

•

Banded ash clearwing still fooling — round exit holes, not D-shaped.

℞

Prescribe · Timing & Materials

•

HWA: fall-window horticultural oil with thorough coverage, or imidacloprid / dinotefuran systemic for large hemlocks; report new-town finds.

•

SLF: scrape masses into alcohol on every visit; inspect anything staged outdoors before it moves.

•

Mites: tap-test conifers; fall-rate horticultural oil where damaging.

•

Fall program: deep-water into dormancy, fertilization and root-zone work live; oak pruning opens in October.

MA

Mid-Atlantic & DMV

NY · NJ · PA · MD · DE · DC · VA · WV

GDD · Accumulated

~3,050–3,700

0

1,500

3,000+

Conditions: SLF egg-laying continues across the region's heaviest populations; box tree moth zones stand in eight MD counties and three NJ counties. HWA scouting season opens on hemlocks from the Poconos to the Blue Ridge.

Diagnose · Active Now

•

SLF egg masses fresh on smooth bark, limbs, stone, and equipment — scraping season in full swing.

•

Hemlock woolly adelgid wool re-emerging — scout ravine and foundation hemlocks now.

•

Box tree moth late larvae on boxwood; monitor in and beyond the quarantine zones.

•

Spruce spider mite on arborvitae and spruce screens; twig girdlers active.

•

Bacterial leaf scorch chronic-visible; Armillaria & Ganoderma fruiting at declining bases.

℞

Prescribe · Timing & Materials

•

SLF: egg-mass scraping as a billable line item; treat trap trees through the feeding tail; report new counties.

•

HWA: fall horticultural oil or imidacloprid / dinotefuran systemics; prioritize stream-side and specimen hemlocks.

•

Box tree moth: Btk / spinosad on active larvae; bag debris; compliance for movement.

•

Mites: tap-test conifer screens; fall-rate oil where damaging.

•

Fall program: fertilization, root-zone work, and fall injections while soil moisture supports uptake; oak pruning opens in October.

SE

Southeast

NC · SC · GA · TN · KY · AL · MS · FL

GDD · Accumulated

~3,900–4,900

0

1,500

3,000+

Conditions: Welcome, Kentucky — now riding with the Southeast card. Hurricane season stays active; scout after every system. Laurel wilt keeps advancing on laurel-family hosts, and HWA remains the southern Appalachians' hemlock fight.

Diagnose · Active Now

•

Fall armyworm still riding storm systems — dawn scouting after rain events.

•

Hemlock woolly adelgid scouting opens in the southern Appalachians (KY, TN, NC highlands).

•

Storm-damaged limbs drawing ambrosia beetles and southern pine beetle.

•

Twig girdlers heavy on pecan and hickory; azalea lace bug late feeding.

•

Laurel wilt on the scout list; Phytophthora on saturated sites.

℞

Prescribe · Timing & Materials

•

Fall armyworm: soap-flush suspect turf; treat small larvae immediately with Btk / spinosad / chlorantraniliprole.

•

HWA: fall horticultural oil or systemics on infested hemlocks; report new-county finds.

•

Storm response: clean-cut torn limbs; assess root plates before remediation promises.

•

Twig girdlers: rake and destroy dropped twigs — eggs overwinter inside them.

•

Fall planting: the Southeast's best establishment window is open.

SC

South-Central & Plains

TX · OK · AR · LA · KS · NE · SD · ND · NM

GDD · Accumulated

~2,500–4,800

No. Plains

—

Gulf Coast

Conditions: The new card — and a region that runs from Gulf humidity to first Northern Plains frosts in one span, so read the range against your latitude. Drought stress drives the borer-and-canker complex across Texas and Oklahoma; EAB's southern front (Hardin Co., TX — the southernmost U.S. detection) added eight Texas counties this year.

Diagnose · Active Now

•

Pecan weevil in its August–October window across TX/OK pecan country — adults emerging and larvae entering nuts.

•

Twig girdlers raining cut twigs under pecan, hickory, and oak; fall webworm nests still heavy on pecan.

•

Ips engraver beetles and Hypoxylon (Biscogniauxia) canker hitting drought-stressed pines and oaks.

•

Oak wilt across the Texas core (76+ counties, including the Tarrant Co. post oak find); EAB advancing on the eastern front.

•

Pine wilt nematode killing Scots and Austrian pines in KS/NE shelterbelts and windbreaks.

℞

Prescribe · Timing & Materials

•

Pecan weevil: trunk traps or barrier bands to monitor; treat per TAMU / OSU thresholds while adults are active — the window closes as shucks split.

•

Oak wilt: honor the Texas no-prune window (Feb 1–Jun 30), paint every oak wound year-round, never move unseasoned oak; trench + propiconazole injection for high-value oaks near a center.

•

Ips / Hypoxylon: deep-water high-value pines and oaks; remove and destroy brood and dead trees — no cure once canker strips bark; stress reduction is the program.

•

Pine wilt: remove and chip or burn nematode-killed pines before spring sawyer-beetle flight; replant with resistant species.

•

EAB: inventory ash in the new Texas counties; emamectin benzoate injection for high-value trees; keep ash wood local.

MW

Midwest & Great Lakes

OH · MI · IN · IL · WI · MN · IA · MO

GDD · Accumulated

~2,800–3,450

0

1,500

3,000+

Conditions: Nights cooling fast. New HWA detections put Michigan at eleven infested counties (Manistee and Van Buren newest) — the Lake Michigan shoreline corridor remains the front. Ohio's statewide SLF quarantine stands; oak pruning opens in October.

Diagnose · Active Now

•

Hemlock woolly adelgid — Michigan's footprint now 11 counties; scout shoreline and landscape hemlocks and report new finds.

•

SLF egg-laying in established populations; watch and report along the Iowa/Illinois front.

•

Spruce spider mite on spruce and arborvitae windbreaks; banded ash clearwing flying.

•

Box tree moth late larvae in quarantine zones; tar spot rake-and-destroy season begins.

•

EAB fall injection window open while soil moisture supports uptake.

℞

Prescribe · Timing & Materials

•

HWA: flip branch tips on every hemlock; fall horticultural oil or imidacloprid / dinotefuran systemics; report suspect finds to MDARD/DNR.

•

SLF: scrape masses; inspect outbound equipment from quarantine counties; report western finds immediately.

•

EAB: fall emamectin benzoate injections for high-value ash; verify exit-hole shape on ash calls first.

•

Tar spot: rake and destroy fallen maple leaves; no spray warranted.

•

Fall program: fertilization and root work now; oak pruning waits for October.

W

West & Pacific

CA · OR · WA · NV · AZ · CO · UT · ID · MT · WY

GDD · Accumulated

Highly variable

Coast / high elev.

—

Inland / low desert

Conditions: Welcome, Wyoming — now riding with the West card. First fall rains reach the PNW; fire season lingers inland. Imperial Co. HLB and Oregon's five-county EAB districts stand.

Diagnose · Active Now

•

Wood-boring beetles on drought-stressed trees — invasive shothole borers, goldspotted oak borer, mountain pine beetle in the high country.

•

Emerald ash borer in Oregon's Willamette Valley; fall injection window open.

•

Armillaria mushroom season opens with PNW rains; spruce spider mite active at elevation.

•

Balsam & hemlock woolly adelgids — wool visible on true firs and western hemlock as temps cool.

℞

Prescribe · Timing & Materials

•

Borers: deep-water before dormancy; keep host wood local; protect high-value ash in EAB zones and report.

•

Adelgids: fall horticultural oil with full coverage where infestations warrant.

•

Armillaria: photograph and map basal mushroom clusters — free diagnostics for declining trees.

•

Fall planting: the West's best establishment season — book installs as heat breaks.

Field notes — read before you spray

Flip the branch tips. HWA wool is visible again — a ten-second check on every hemlock you pass is how new counties get caught at the containable stage.

A dying tree deserves a verified cause. Field observations — even convincing ones — get confirmed before they drive a program: sample, lab-test, and report suspects to your state forest health office. That's how real outbreaks get on the map.

Two weeks to oak season. October opens northern oak pruning — build the winter work list now while crowns still show their dead wood honestly.

Sources · Cooperative Extension & USDA

Compiled from public reporting by cooperative extension and state/federal partners, including Michigan Dept. of Agriculture & Rural Development (HWA detections); USDA APHIS & Forest Service; Cornell NYSIPM; Connecticut DEEP & CAES; NY DEC & Ag and Markets; Maryland Dept. of Agriculture & University of Maryland Extension; Rutgers Plant & Pest Advisory & NJ Forest Service; Penn State Extension; NC State & Clemson; new for the South-Central & Plains card: Texas A&M Forest Service, Oklahoma State University Extension, SDSU Extension Tree Pest Alert, and LSU AgCenter; Michigan State, Iowa State & UMN Extension; UC Statewide IPM Program; CDFA; Oregon Dept. of Agriculture / ODF; and USDA NIFA. Regional summaries are paraphrased; consult the original bulletins and your local extension office for specifics.

HWA wool comes out of hiding, Michigan's map grows to 11 counties, and a sixth region joins the report — Sep 14–21.

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