ISLIP - Gypsy moth caterpillars are back and defoliating trees throughout Long Island.

Certified horticulturist Evan Dackow calls the gypsy moth caterpillar "pesty, and very hard to get rid of."

Dackow says residents can either use a non-toxic spray to rid trees of the pests, or wait until a natural fungus forms. He says the fungus might not appear for a while due to the dry spring.

Experts at the Cornell Cooperative Extension say last year's invasion of gypsy moth caterpillars was the worst in 25 years, and that this year could be even worse.