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To the crews in the buckets, on the ropes, and behind the spray rigs — this bulletin is for you. Enjoy the day; the trees will keep.

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National Snapshot

Egg-mass season opens as storm season peaks

September arrives with two clocks running. Spotted lanternfly egg-laying is underway — fresh masses look like wet gray putty drying to cracked mud, and every one scraped now removes up to 50 lanternflies from next spring. Meanwhile hurricane season hits its climatological peak this week, driving fall armyworm flights north and priming saturated-soil disease. Scale crawler windows have closed (dormant oil is the plan now), fall PHC season is open, and oak pruning waits one more month.

Invasive

SLF egg masses are appearing on smooth bark, undersides of limbs, and equipment. Scrape into alcohol or smash thoroughly; check trucks, trailers, and anything staged outdoors before it moves. Maryland's quarantine is now effectively statewide; Ohio has been statewide since February.

Caterpillar

Fall armyworm is the outbreak risk of the week as storm systems ferry moths north (see the featured pest). Fall webworm and oakworm are wrapping up; tolerate the stragglers.

Sap feeder

Crawler windows closed — settled scale nymphs no longer respond to contact sprays. Book dormant oil rounds now for magnolia, prunicola, crapemyrtle bark scale, and lecanium clients.

Borer

Twig girdlers raining cut twigs under oak, hickory, and pecan — rake and destroy. EAB and ambrosia larvae tunnel on unseen; storm-damaged limbs draw borers, so clean-cut tears promptly.

Disease

Storm-soil disease: hurricane rains flare Phytophthora on saturated sites while Northeast drought keeps Armillaria aggressive — the below-ground read is in the Soil-Borne Watch. Tar spot and leaf scorch remain peak-visible.

Planning

Fall PHC is live: fertilization and root-zone work, deep watering before dormancy, fall trunk injections, and dormant-oil scheduling all book now. October opens oak pruning and Armillaria mushroom checks.

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

Fall Armyworm

Spodoptera frugiperda

This week's pest on the chart, because the calendar says peak hurricane season and that's exactly what fall armyworm rides. Moths can't overwinter in most of the country — they surge north on tropical storm systems, and females start laying the moment they land. Larvae (look for the inverted "Y" on the head capsule) feed in masses and can take turf, young plantings, and ornamental grasses from green to brown in 48–72 hours, usually noticed at dawn when birds flock to the feeding front. The window between "first larvae" and "too big to control" is about a week.

Risk Peak

Now – Oct

Targets

Turf·Youngstock

Rx Note

Scout after storms

℞ — Scout at dawn or dusk in the week following any tropical rain event — soap flushes (a squirt of dish soap in a gallon of water over a square yard) bring larvae up fast. Treat small larvae immediately with Btk, spinosad, or chlorantraniliprole; large larvae shrug off most materials, so speed beats product choice. Irrigated, fertilized turf and fresh sod are preferred targets — check those first. Damage to established turf usually regrows; young trees and new plantings are where real losses happen, so prioritize them.

Regional Alert

SLF Egg-Mass Season Opens

Fresh masses (30–50 eggs each) look like wet gray putty and dry to a cracked-mud smear about an inch long — on smooth bark, limb undersides, stone, fences, grills, vehicles, and staged equipment. Every mass destroyed now is up to 50 fewer lanternflies next spring.

Status

17 states and counting — confirmed populations now span PA through the Midwest and New England; Ohio's quarantine went statewide in February (all 88 counties) and Maryland's March expansion made its quarantine effectively statewide.

Western Front

Iowa — Dallas County — immature lanternflies were reported to the Iowa Dept. of Agriculture — the invasion's westernmost signal. Operators in IA, IL, and MO: photograph and report anything suspicious immediately; a county caught at the egg-mass stage is a county that can still be contained.

℞ Make scraping a line item. Add egg-mass checks to every fall/winter visit (scrape into alcohol or crush thoroughly — a fingernail test: they pop), inspect trucks and staged materials before they move, and report finds outside known zones. This is the highest-leverage SLF work of the entire year.

Soil-Borne Disease Watch

Storm Water Meets Dry Roots

Peak hurricane week sharpens the split: tropical rain saturates southern and coastal soils (Phytophthora conditions) while the interior Northeast stays droughty (Armillaria conditions). Same wilted look above ground, opposite causes below.

Wet · SE / Mid-Atl

Phytophthora root & crown rot — 4–8 hours of warm, saturated roots is enough for infection — storm-flooded beds and poorly drained sites are prime this week. Wilt that doesn't recover with watering, darkened gummy crown bark, reddish inner-bark streaks. Fix drainage first; phosphite drenches and mefenoxam are protective-only for high-value neighbors, not cures.

Dry · NE / Interior

Armillaria root rot — drought keeps this fungus in attack mode on stressed oaks, maples, and conifers. White mycelial fans under collar bark and shoestring rhizomorphs confirm it; honey-colored mushroom clusters will fruit at the base once fall rains arrive — mark declining trees now for October mushroom checks rather than removing mid-season. No fungicide; vigor and irrigation are the treatment.

Flagging Now

Verticillium wilt — one-sided branch flagging and early color on maple, redbud, and magnolia remain peak-visible; confirm with sapwood streaking and a lab culture before condemning a tree. Replant only with non-hosts (oak, beech, sycamore, conifers).

℞ After every storm, walk the drainage. Standing water at a root collar for a day is a disease event, not just a puddle. Air-spade suspicious collars, correct grade and irrigation before writing any fungicide, and log soil observations with the crown symptoms — below-ground cause, above-ground evidence.

Regional Rx · 5 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

~2,150–2,550

0

1,500

3,000+

Conditions: Accumulation slowing as nights cool; drought stress persists into fall. Laurel wilt (Suffolk Co.) and oak wilt (Finger Lakes) districts stand; CT continues requesting SLF reports for Windham, Tolland, and Litchfield.

Diagnose · Active Now

•

SLF egg masses appearing on tree-of-heaven, maple, and outdoor equipment.

•

Box tree moth larvae still active on boxwood; bagworm males flying.

•

Twig girdlers dropping oak and hickory twigs; Verticillium flagging on maple.

•

Armillaria collapses on drought-stressed trees; mushroom watch begins with fall rains.

•

Fall needle shed starting on white pine and arborvitae — normal, but it will generate calls.

℞

Prescribe · Timing & Materials

•

SLF: scrape and destroy egg masses (alcohol or thorough crushing); inspect vehicles and staged materials before moving.

•

Scale: book dormant-oil rounds; crawler sprays are done for the year.

•

Drought recovery: deep-water high-value trees through fall; fall fertilization and root-zone work open now.

•

Client education: inner-needle yellowing on conifers in September is seasonal shed, not disease — photograph and reassure.

MA

Mid-Atlantic & DMV

NY · NJ · PA · MD · DE · DC · VA · WV

GDD · Accumulated

~2,850–3,450

0

1,500

3,000+

Conditions: SLF egg-laying underway across the region's heaviest populations; Maryland's quarantine is effectively statewide. Box tree moth zones stand in eight MD counties and three NJ counties. Hurricane remnants keep foliar and soil disease pressure high.

Diagnose · Active Now

•

SLF egg masses fresh on smooth bark, limb undersides, stone, and equipment — scraping season is open.

•

Box tree moth larvae active; monitor every boxwood, quarantine zone or not.

•

Fall armyworm watch after tropical rain; twig girdlers dropping twigs.

•

Bacterial leaf scorch at peak expression; Phytophthora flaring on saturated sites.

•

White prunicola & magnolia scale settled — dormant oil is the play now.

℞

Prescribe · Timing & Materials

•

SLF: build egg-mass scraping into every fall visit; treat trap trees through the feeding tail; report new counties.

•

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

•

Fall armyworm: soap-flush suspect turf after storms; treat small larvae fast.

•

Soil disease: fix drainage before writing fungicides; phosphite protective-only on high-value Phytophthora sites.

•

Fall program: fertilization, root-zone work, and fall injections book now; oak pruning opens in October.

SE

Southeast

NC · SC · GA · TN · AL · MS · FL · VA

GDD · Accumulated

~3,600–4,600

0

1,500

3,000+

Conditions: Peak hurricane week — storm systems drive fall armyworm flights, saturate soils for Phytophthora, and leave wind damage that draws borers. Laurel wilt keeps advancing.

Diagnose · Active Now

•

Fall armyworm outbreak risk at its annual peak — scout turf, sod, and young plantings after every system.

•

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

•

Crapemyrtle bark scale settled; sooty mold heavy; twig girdlers on pecan.

•

Phytophthora flaring on saturated, poorly drained sites.

•

Laurel wilt — keep redbay, sassafras, and bay on the scout list.

℞

Prescribe · Timing & Materials

•

Fall armyworm: dawn/dusk scouting + soap flushes after storms; Btk / spinosad / chlorantraniliprole on small larvae immediately.

•

Storm response: clean-cut torn limbs promptly; assess root-plate movement before remediation promises.

•

Soil disease: drainage first; mound-plant replacements on known Phytophthora ground.

•

CMBS: dormant hort oil scheduling opens as temps ease.

•

Laurel wilt / borers: keep host wood local; report suspects.

MW

Midwest & Great Lakes

OH · MI · IN · IL · WI · MN · IA · MO

GDD · Accumulated

~2,600–3,250

0

1,500

3,000+

Conditions: Nights cooling; season winding toward fall programs. Ohio's statewide SLF quarantine and expanded box tree moth zones stand — and immature SLF were reported in Dallas County, Iowa, the invasion's western front. Oak pruning opens in October.

Diagnose · Active Now

•

SLF — egg-laying beginning in established Ohio/Michigan populations; watch the Iowa front and report any find.

•

Box tree moth larvae active in quarantine zones; bagworm males flying.

•

Twig girdlers dropping twigs; fall webworm wrapping up.

•

Verticillium flagging on maple; tar spot at peak (cosmetic).

•

EAB larvae tunneling; fall injection window open for high-value ash.

℞

Prescribe · Timing & Materials

•

SLF: scrape egg masses; inspect anything moving out of quarantine counties; report finds west of the front immediately.

•

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

•

EAB: fall emamectin benzoate injections for high-value ash while soil moisture supports uptake.

•

Tar spot: rake and destroy fallen maple leaves to cut next year's inoculum; no spray warranted.

•

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

W

West & Pacific

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

GDD · Accumulated

Highly variable

Coast / high elev.

—

Inland / low desert

Conditions: Fire season continues at peak across the interior; irrigation stress drives the borer picture. 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, Mediterranean oak borer.

•

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

•

Yellowjackets at peak aggression around honeydew and job sites.

•

Armillaria active beneath drought-stressed conifers; fall mushroom watch approaching.

℞

Prescribe · Timing & Materials

•

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

•

HLB zone: citrus material stays local; cooperate with trapping crews.

•

Fall planting: window opens as temperatures ease — best establishment season in most of the West.

•

Fire: hold defensible space through the remainder of the season.

Field notes — read before you spray

Scrape now, spray less next June. Every SLF egg mass destroyed this fall is 30–50 fewer nymphs in spring — the best ROI on the calendar.

Storm weeks are scouting weeks. Fall armyworm arrives on tropical systems and outgrows control in days — soap-flush suspect turf at dawn after every event.

Book the dormant season now. Dormant oil, fall injections, root-zone work, and October oak pruning are all schedulable today — the calendar fills fast once leaves drop.

Sources · Cooperative Extension & USDA

Compiled from public reporting by cooperative extension and state/federal partners, including USDA APHIS (SLF biology & egg-mass guidance); Cornell NYSIPM (SLF distribution); Ohio Dept. of Agriculture & OSU Extension (statewide SLF quarantine); Maryland Dept. of Agriculture (quarantine expansions); Iowa Dept. of Agriculture & Land Stewardship (Dallas Co. report); Connecticut CAES; NY DEC & Ag and Markets; Kansas State & regional extension fall armyworm monitoring; UMass Extension; University of Maryland Extension; Rutgers; NC State & Clemson; Michigan State, Iowa State & UMN; UC Statewide IPM Program; Penn State Extension; CDFA; Oregon Dept. of Agriculture / ODF; and USDA NIFA / Forest Service. Regional summaries are paraphrased; consult the original bulletins and your local extension office for specifics.

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