Tree Pest & Insect Diagnosis — Know What You Are Dealing With.
From emerald ash borer to scale and mites, the pest decides the plan. We identify what you have, tell you whether the tree is worth protecting, and do the pruning and removal side of the work. We do not apply pesticides, and we will say plainly when that is what you need.
Free Pest Assessment
Same-day assessment. No obligation, no surprise fees.
The wrong bug can kill a mature tree in a season or two.
Insect pests like emerald ash borer have taken most of the untreated ash across the GTA. Others weaken a tree gradually: aphids and scale drop sticky honeydew, borers work under the bark, mites speckle and curl the leaves.
Identification decides everything, because the answer for a borer looks nothing like the answer for aphids. We diagnose the specific pest, assess how far it has gone, and tell you what a realistic plan costs.
We are arborists, not exterminators. Ontario restricts pesticide application to licensed applicators, so injections and sprays are not something we sell. What we do is the diagnosis, the pruning and removal work, the cultural fixes that make a tree less attractive to pests in the first place, and a straight answer on whether a chemical programme is worth your money.
Signs of a pest problem
- D-shaped exit holes (emerald ash borer)
- Sticky “honeydew” or black sooty mould on leaves
- Curling, speckled, or distorted foliage
- Sudden canopy thinning from the top down
- Sawdust-like frass at the base or in bark
- Visible insects, webbing, or egg masses
Identify First, Then Decide
A named pest, a realistic prognosis, and the work we can actually do about it.
- Pest identificationWe pinpoint the exact insect before anyone spends a dollar on it.
- Infestation assessmentHow far it has spread and whether the tree is still worth keeping.
- Straight advice on treatmentWhether a chemical programme is worth it, what it costs over ten years, and when it is money wasted.
- Pruning out the damageInfested, dead and dying wood taken out to slow the spread and make the tree safe.
- Cultural fixesWatering, mulching and compaction relief, because stressed trees are the ones pests take first.
- Honest save-or-remove callPast saving, we say so and handle the removal. Dead ash gets brittle fast, so timing matters.
Pests & Insects: The Details Homeowners Ask For
Straight answers on timing, permits, access, and what it costs you.
- What we do
- Identification, infestation assessment, the pruning and removal work, and the water and soil fixes. We do not apply pesticides.
- What we do not do
- Injections, sprays and dormant oil. Ontario restricts registered pesticides to licensed applicators, so we tell you whether it is worth arranging rather than selling it to you.
- Emerald ash borer
- Protection means TreeAzin injected into the trunk every two years, indefinitely, by a licensed applicator. Worth it on a canopy still largely full, and wasted on a tree more than about a third dead.
- Spongy moth (formerly LDD)
- Two of the three answers need no chemical: egg masses scraped off the trunk between September and April, and burlap bands in May and June to trap caterpillars climbing back up.
- Bronze birch borer
- The reason white birches die from the top down here. The real prevention is water and mulch through a dry August, because the borer takes stressed trees first.
- Scale, aphids and honeydew
- The sticky film on a car parked under a maple or linden. It is a nuisance rather than a threat to a healthy tree, and it washes off.
Deciding whether an ash tree is worth treating
Emerald ash borer has killed most of the untreated ash in the GTA. The larvae feed in the layer just under the bark that moves sugar around the tree, and by the time the canopy thins the damage is structural. Ash killed by the borer becomes brittle fast, which is why standing dead ash is a removal priority rather than a wait-and-see tree.
Treatment works, with conditions. TreeAzin is injected directly into the trunk by a licensed applicator and repeated every second year for the life of the tree. It is worth doing on a healthy ash with a canopy still largely full, and on a large specimen that shades a house, because the injection cost over a decade comes in under the removal. A tree already thinning past a third is money better spent on replacement.
The stopping decision is the one owners get wrong. Injections are not a course of treatment with an end date. Skip a cycle and the borer comes back, so a tree entering the programme is a standing commitment worth pricing before the first injection rather than after the third. We are not the ones selling it, which is why we will tell you when the honest answer is to take the tree down and plant something else.
Woodpecker activity high in an ash, blonde patches where bark has flaked off, and shoots sprouting from the trunk are the three signs that the borer is already at work. Any two of those in the same tree means a diagnosis visit now rather than next spring.
The North York Tree Standard
The same proven four steps on every job.
Call or Request a Quote
Tell us about the tree. Emergencies answered 24/7.
Free On-Site Assessment
A certified arborist confirms the plan and gives a written price.
Safe, Insured Pest Work
Carried out by an equipped, fully insured crew.
Spotless Cleanup
Everything hauled away — your yard left clean and safe.
Named, Assessed, Acted On
A few recent North York jobs — handled safely and cleaned up completely.
Two mature ash trees
Owners wanted to know whether protecting both was worth the ten-year cost.
Linden dripping honeydew
Sticky honeydew and sooty mould coating the patio below.
Birch with bronze borer
Top-down dieback from bronze birch borer.
“They identified emerald ash borer and told us straight which of our two ash trees was worth spending money on. No upsell, no scare story. The one they said to keep is still healthy.”
Something eating your trees?
Get it identified by a certified arborist across North York & the GTA. Free assessment.
Questions Homeowners Ask Us
Do you spray or inject trees?
No. Ontario restricts pesticide application to licensed applicators, and that is not what we are. We diagnose the pest, do the pruning and removal work, and tell you honestly whether a treatment programme is worth arranging with a licensed applicator.
Can you save a tree with emerald ash borer?
An ash with a mostly full canopy can be protected by injections repeated every two years, indefinitely, which a licensed applicator carries out. Past about a third dead, that money is better spent on removal and replanting. We give you the assessment that decides which situation you are in.
How do I know which pest I have?
That is our job. Different pests leave different signs and lead to completely different decisions, so identification comes before anyone quotes you anything.
What can you do about pests without pesticides?
More than most people expect. Pruning out infested and dead wood, removing trees that have become a source of spread, scraping egg masses, and fixing the water and soil problems that made the tree a target. Pest damage usually follows stress.
What if the infestation is too advanced?
We will tell you honestly. A badly infested tree becomes a hazard, and dead ash in particular turns brittle quickly, which makes removal harder and more expensive the longer it stands.
Is it too late to save my ash tree?
It depends on the canopy. An ash still carrying most of its leaves responds well to TreeAzin injections every two years, which a licensed applicator carries out. One that has lost more than about a third of its crown rarely recovers, and dead ash turns brittle quickly, which makes removal harder and more expensive the longer it stands.
How often does TreeAzin have to be repeated?
Every two years, indefinitely. It is a protection programme rather than a cure, so the number to compare against removal is the ten-year total, not the first injection. We give you both figures before you commit to either.
What are the caterpillars stripping my oak every few years?
Spongy moth, which used to be called LDD or gypsy moth. It runs in cycles of several years. Scraping egg masses off the trunk from September through April and banding with burlap in late spring cuts the next generation without any chemical, and a healthy oak survives a defoliation, though several years running will weaken it.
Something is dripping sticky liquid onto my car. What is it?
Honeydew, which is aphid or scale excretion from the tree above. It washes off, and in normal numbers it does the tree no harm. Move the car, and treat a heavy recurring infestation as a sign the tree is stressed by something else.