Question 1

I'm seeing spotted lanternflies on my trees. What should I do?

Accepted Answer

The spotted lanternfly Lycorma delicatula is an invasive planthopper spreading rapidly through the eastern US. While it rarely kills established trees outright, it stresses them, produces enormous amounts of honeydew leading to sooty mold, and is a major nuisance and agricultural threat. Identification by season: - Spring/early summer: Black nymphs with white spots, later developing red patches - Late summer/fall: Showy adults ~1 inch long with gray forewings black spots and bright red underwing

Question 2

There are small cone-like bags hanging from my evergreen. What are they?

Accepted Answer

Those 1-2 inch spindle-shaped "bags" covered in bits of foliage are bagworms Thyridopteryx ephemeraeformis — caterpillars that build a protective case from the host plant's own needles or leaves. They're especially destructive on arborvitae, junipers, and spruce, and a heavy infestation can kill an evergreen. Why they're easy to miss: - The bags are perfectly camouflaged to look like cones or bits of the plant - By the time you notice browning, the larvae may have already done significant feedin

Question 3

There are cottony white masses on my tree's branches. What are they?

Accepted Answer

Fluffy, cottony white masses on twigs and branches are usually the protective wax of sap-feeding insects — most often woolly aphids, cottony cushion scale, or mealybugs. The white "cotton" is a waxy secretion that shields the soft-bodied insects underneath. How to tell them apart: - Woolly aphids: Cottony tufts that may seem to "fly" winged forms; often on alder, apple, beech, elm. Produce honeydew. - Cottony scale e.g., cottony maple scale: White cottony egg sacs attached to twigs, with the sca

Question 4

Beetles are skeletonizing my tree's leaves in summer. How do I stop them?

Accepted Answer

Leaves chewed down to a lacy skeleton in mid-summer, with metallic green-and-copper beetles clustered on them, are the work of Japanese beetles Popillia japonica. Adults feed on the tissue between leaf veins, leaving the characteristic lace pattern, and favor lindens, crabapples, cherries, birches, and roses. Life cycle to understand: - Adults emerge late June through August and feed for 4-6 weeks - They release aggregation pheromones — a few beetles quickly become a swarm - Females lay eggs in

Question 5

What are these D-shaped holes in my ash tree?

Accepted Answer

D-shaped exit holes in an ash tree are the unmistakable calling card of the emerald ash borer EAB Agrilus planipennis, the most destructive forest insect pest in North American history. EAB has killed hundreds of millions of ash trees since its discovery near Detroit in 2002. Confirming EAB infestation: - Exit holes are about 1/8 inch wide and distinctly D-shaped flat on one side - Serpentine, S-shaped larval galleries beneath the bark filled with frass sawdust - Canopy thinning starting at the

Question 6

Small green worms are eating my tree leaves. What are they and how do I stop them?

Accepted Answer

Small green caterpillars often called "worms" feeding on tree leaves could be several species, but the most common culprits are cankerworms, inchworms, fall webworms, or sawfly larvae. Identification matters because treatment differs. Quick identification guide: - Cankerworms / inchworms: Move in a characteristic "looping" motion. Very common on oaks, maples, elms, and lindens in spring. About 1 inch long. - Fall webworms: Build silky white web nests on branch tips. Yellowish-green with black sp

Question 7

I see tiny holes and sawdust piles at the base of my tree trunk. What's causing this?

Accepted Answer

Tiny holes with accumulations of fine sawdust called frass at the base of your tree indicate boring insect activity. This is a serious concern because wood-borers feed inside the trunk, disrupting the tree's vascular system and weakening its structural integrity. Common culprits by hole characteristics: - Round holes, 1/16 inch: Ambrosia beetles — they bore into stressed or recently transplanted trees and cultivate fungal gardens inside - Round holes, 1/4 inch with coarse frass: Clearwing borers

Question 8

A sticky substance is dripping from my tree onto my car. What is it?

Accepted Answer

That sticky substance coating your car and everything else under the tree is honeydew — a sugary waste product excreted by sap-sucking insects. It's not sap from the tree itself, but rather the byproduct of an insect infestation in the canopy. Common honeydew-producing insects: - Aphids — the most likely culprit. Tiny 1-3mm soft-bodied insects clustered on leaf undersides and new growth. Many species, many colors. - Scale insects — look like small bumps on twigs and branches. Soft scales produce

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