Tree pests and diseases to know, country by country

This page describes what the agencies say and where to report.

United States

The federal agency is USDA APHIS (Animal and Plant Health Inspection Service). Its pest pages send most reports to State plant health officials, so a crew's first call is usually the state.

Pest	What APHIS says	Report to
Emerald ash borer	Found in 38 states and DC. Spread by moving ash firewood, logs or nursery stock.	APHIS form or phone line
Asian longhorned beetle	First found in Brooklyn in 1996. Eradication under way in NY, MA, OH and SC.	APHIS form in those states; else the state
Spongy moth	Caterpillars feed on over 300 species. Found throughout the Northeast.	State plant officials
Spotted lanternfly	19 states and DC. First found in Pennsylvania in 2014. Likes tree-of-heaven.	State contact list
Sudden oak death	No cure. Killed millions of tanoak and coast live oak in California and Oregon.	State plant officials

Emerald ash borer and Asian longhorned beetle

APHIS gives 1-866-322-4512 for emerald ash borer questions. It describes emerald ash borer signs as D-shaped exit holes, dead branches near the top of ash trees, excessive branching on the trunk and vertical cracks in the bark. For Asian longhorned beetle it lists round exit holes about the size of a dime or smaller. It adds that infested trees can become safety hazards, because branches can drop and trees can fall, especially in storms.

Spongy moth and spotted lanternfly

The spongy moth was called the gypsy moth until its common name changed. APHIS says spotted lanternfly eggs are laid on any hard surface, including vehicles and trailers. See the APHIS lanternfly page for the state contact list.

Oak wilt and Dutch elm disease

Oak wilt, Wisconsin. The DNR says sap-feeding beetles carry spores to fresh wounds and recently cut oak stumps. It says a red oak that shows wilting loses most of its leaves and dies within about a month. It advises that if oaks are pruned between April and July, wound sealer is applied right after the cut. See the Wisconsin DNR oak wilt page.
Oak wilt, Minnesota. The DNR says it was first found there around 1945 and is widespread in east-central and southeast Minnesota. It asks for reports through apps, the local DNR forestry office, or the University of Minnesota Plant Disease Clinic. See the Minnesota DNR page.
Dutch elm disease, Minnesota. University of Minnesota Extension says three elm bark beetles carry the fungus from tree to tree, and that the disease is now in every county. See the Extension page.

For sudden oak death, APHIS says an official diagnosis must be confirmed by laboratory testing. See the APHIS P. ramorum page.

Canada

The Canadian Food Inspection Agency (CFIA) runs the plant health pages. Each pest page has an online sighting form.

Pest	What CFIA says	Where it is
Emerald ash borer	Kills all ash species. Adults can fly up to 10 km. Infested ash generally die after 2 to 3 years.	Regulated areas in ON, QC, NB, NS, MB and BC
Spongy moth	Called European gypsy moth or LDD moth before 2022.	ON, QC, NB, NS and PE; reports wanted in BC, AB, SK, MB and NL
Hemlock woolly adelgid	Egg sacs look like cotton balls at the base of needles.	Regulated in British Columbia and parts of Nova Scotia and Ontario
Asian longhorned beetle	Found in Mississauga and Toronto in August 2013. Movement order repealed June 9, 2020.	Declared eradicated there in 2020
Oak wilt	First confirmed detection in Canada was in Niagara Falls, Ontario.	Ontario

CFIA asks people not to move firewood, especially ash wood or regulated materials, out of regulated areas, and to report any detection outside them immediately. See the CFIA emerald ash borer page.

For hemlock woolly adelgid, CFIA gives tree death within 4 to 15 years. The oak wilt page tells people not to prune oak trees between April and November. See the CFIA oak wilt page and the hemlock woolly adelgid page.

United Kingdom

Forest Research, the research agency of the Forestry Commission, runs TreeAlert. It takes reports of suspected tree pests and diseases found anywhere in Great Britain. Northern Ireland uses TreeCheck, the all-Ireland tree disease reporting tool. Reports go through the TreeAlert site.

Pest	What the agency says	Status
Ash dieback	Caused by a fungus of eastern Asian origin.	Well established, present in every county
Oak processionary moth	Introduced to England in 2005. Government control programme.	Most of Greater London and nearby counties
Ramorum disease	Sudden oak death on oak. First UK finding on viburnum in Sussex, February 2002.	Present
Asian longhorn beetle	One breeding population found at Paddock Wood, Kent in 2012.	Not known to be present
Xylella	Bacterial disease spread by xylem-feeding insects.	Not known to occur in the UK

On ash dieback, Forest Research says public safety must be the priority, so the trees' safety should be monitored as the disease progresses, and they should be pruned or felled if they or their branches threaten injury or damage. On oak processionary moth it tells people not to touch or approach the nests or caterpillars, and to report nests even if no caterpillars are seen. See the oak processionary moth page.

For ramorum disease, Forest Research gives non-online routes for plants outside woodland or in trade. In England and Wales it is the Animal and Plant Health Agency (APHA) by email or on 0300 1000 313. In Scotland it is the Scottish Government by email or on 0131 244 8923. In Northern Ireland it is DAERA at 0300 200 7847. See the ramorum disease page.

The Defra Plant Health Portal page on Xylella was last updated on December 17, 2025. See the Plant Health Portal Xylella page.

Australia

Plant Health Australia says any unusual plant pest or disease should be reported immediately to the relevant state or territory agriculture agency through the Exotic Plant Pest Hotline, 1800 084 881. Callers choose the state or territory from an automated menu. For some states it is answered from 08:30 to 16:30 Monday to Friday, with a message service outside those hours. See the Plant Health Australia reporting page.

Pest or disease	What the agency says	Where to report
Polyphagous shot-hole borer	Detected in Western Australia in August 2021. A Quarantine Area covers the Perth metro area.	MyPestGuide Reporter app, or the PaDIS line
Myrtle rust	The Botanic Gardens page says to report suspected cases.	Exotic Plant Pest Hotline
Xylella	Plant Health Australia calls it one of Australia's highest-priority exotic plant pests.	Exotic Plant Pest Hotline

Polyphagous shot-hole borer

The Western Australia Department of Primary Industries and Regional Development (DPIRD) says this beetle is a declared pest in that state and a prohibited organism under section 12 of the Biosecurity and Agriculture Management Act 2007, and that any person who finds or suspects it must report it to the department. DPIRD gives PaDIS as 08 9368 3080. The page lists signs seen when pruning: 1 mm shot-holes, galleries, dieback, staining, frass and gumming. It says not to move plants or cuttings with stems over 2 cm in diameter outside the Perth metro area, and that tools including chainsaws and woodchippers that touch infested wood should be sanitised, with 70% ethanol the preferred disinfectant. The zones and current rules are on the DPIRD page. It was updated November 12, 2025.

Myrtle rust and Xylella

The Australian National Botanic Gardens page says to report suspected myrtle rust to the Exotic Plant Pest Hotline. Plant Health Australia describes national freedom claims for Xylella.

New Zealand

New Zealand's agencies split the work by pest. The sections below give what the kauri protection programme and the Department of Conservation say, and who to tell.

Kauri dieback

Tiakina Kauri, part of Biosecurity New Zealand, says kauri are threatened by a soil-borne pathogen called Phytophthora agathidicida (PA), which causes kauri dieback disease. Ten rules came in under the National PA Pest Management Plan on August 2, 2022. The rules summary says:

Anyone going off track or onto a track where they will touch the forest floor must clean all visible soil and organic matter off items that may touch the ground, before they enter and when they leave. It names tools, cars, bikes, shoes and gloves (Rule 8).
Earthworks within a kauri hygiene zone, 3 times the radius of the dripline of the canopy, need an earthworks risk management plan from August 2, 2023 (Rule 5).
Anyone with unhealthy kauri on land they live on or own must let Tiakina Kauri or the regional council know (Rule 1).
Where non-compliance is clear and substantial or continued, infringement fees range from NZ$300 to NZ$400. A Biosecurity Act charge can bring a criminal conviction and a maximum fine of NZ$5,000 for an individual and NZ$15,000 for a corporation.

Its civil and forestry page says moving soil by vehicles and people carries a risk of spreading PA. See the National Plan rules summary.

Where the tree is	Who to tell	Contact
Public conservation land	Local Department of Conservation office	Via the DOC site
Auckland	Auckland Council	09 301 0101
Bay of Plenty	Regional council	0800 884 880
Northland	Regional council	0800 002 004
Waikato	Regional council	0800 800 401
Outside the upper North Island	Tiakina Kauri	Email, see the page below

For areas outside the upper North Island the page gives an MPI kauri email address. Those contacts come from the report sick kauri page, for private or council land in the upper North Island.

Myrtle rust

The Department of Conservation says myrtle rust is a wind-borne fungal disease that has spread throughout the North Island and to parts of the South Island and Chatham Island, and cannot be eradicated. It affects pōhutukawa, mānuka and rātā, and exotic plants such as bottlebrush and lilly pilly. It asks people to report sightings on the iNaturalist website or app, and to contact the local DOC office for finds on public conservation land. See the DOC myrtle rust page.