Spongy Moth & Oak Trees in Ocean County, NJ

Published October 19, 2026 · Ocean County Tree Service

What happened in 2026

The spongy moth (Lymantria dispar dispar, formerly called gypsy moth) is, in the words of the NJ Department of Agriculture, the most destructive forest insect pest in New Jersey's forests. Its caterpillars feed on oaks and other hardwoods from late spring into early summer. The state's NJDA 2026 aerial defoliation survey mapped 2,800 acres of defoliation statewide this summer. In Ocean County it found 16 acres in Berkeley Township and 24 acres in Jackson Township, all in the moderate (25–50% defoliation) class. That's small next to Morris or Sussex County, but if your street was one of the stripped patches, your oaks took a real hit.

Will a defoliated oak die?

Usually not from one year. A healthy oak typically pushes out a second set of leaves by midsummer. The danger is repeat defoliation two or more years running, or defoliation on a tree that was already stressed by drought, root damage from construction, or sandy, dry Pinelands-edge soil like much of Jackson and western Berkeley. Those trees can decline and die over a few years, and dead oaks get brittle fast.

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What to check this fall and winter

Egg masses: tan, fuzzy patches about the size of a quarter to a half-dollar on trunks, under limbs, on fences, sheds, firewood and outdoor furniture. They're laid in summer and hatch in spring.
Scrape and destroy them between fall and April: scrape into a container of soapy water. Don't just knock them on the ground.
Dieback: after leaf drop, look for dead twigs and branches at the top of the crown. Thin, patchy leaf-out next spring is another warning sign.
Other trouble: mushrooms at the base, cracked bark or a new lean mean the tree needs a professional look regardless of the moth.

Can my town spray?

The state runs a voluntary aerial suppression program using the biological insecticide Bacillus thuringiensis (Bt), sprayed on qualifying residential and recreational forest in spring. According to NJDA's program Q&A, the state only works through municipalities, and an area generally has to average more than 500 egg masses per acre over at least 50 acres to qualify. Homeowners can ask their town to request an egg-mass survey. For a single valuable tree, a licensed tree company can talk through treatment options for next spring.

When to prune or remove a damaged oak

If an oak needs pruning or removal, Rutgers NJAES advises doing oak work from December through February, outside the growing season, to reduce disease risk. Oaks with major dead limbs over the house, driveway or street shouldn't wait for next year's leaf-out, especially going into nor'easter season. See dying ash and oak trees, dead tree removal, and the town pages for Jackson and Berkeley (Jackson and Berkeley both have tree permit rules, covered in the permit guide).

Is spongy moth the same as gypsy moth?

Yes. It's the same insect, Lymantria dispar dispar. The common name was changed to spongy moth in 2022, and New Jersey's program calls it LDD.

Where was spongy moth defoliation in Ocean County in 2026?

The NJ Department of Agriculture's 2026 aerial survey mapped 16 acres in Berkeley Township and 24 acres in Jackson Township, all moderate defoliation.

Should I cut down an oak that lost its leaves to spongy moth?

Not automatically. Healthy oaks usually re-leaf the same summer. Repeat defoliation, existing stress, or large dead limbs are the reasons to have it assessed for removal.

Cost and permit guides

Sources are linked in the text and can change. This is general information, not legal, insurance or professional advice. Free referral service, not a tree company. Your request goes to one independent local tree company, which may pay us for the referral.