COAL TOWNSHIP - The gypsy moth has made an unwelcome arrival in lower Northumberland County.
The moth is in its larva stage after having hatched within the past few weeks. The black quarter-inch caterpillars are covered in hair that can be an irritant to human skin, and a nuisance to flick off clothing at a barbecue or a ball game. They'll grow 2 to 3 inches before entering the pupa stage and emerge as moths.
Countless caterpillars have swarmed the grounds of the Shamokin Area School District's west-end campus. The tiny bugs chased elementary students from the playgrounds. Outdoor recess was cancelled since Wednesday after several students had rashes. The school physician approved nurses to use allergy medication if necessary. Principal Mary Teresa Komara said indoor recess will continue until the bugs are mostly gone.
Threat to trees
Larvae may make man itch and scratch, but the destructive bugs pose a serious threat to Pennsylvania's woodlands.
The bugs aren't native to the Northeast, but they've made it their home after migrating from Europe into Massachusetts in 1869 and moving as far south as North Carolina. Millions of oak trees have been killed by gypsy moth larvae in the Keystone State since the invasive species was discovered here in the 1930s.
Oak, apple, birch and willow are among the insects' preferred trees to feed on. Larvae defoliated 214,000 acres last year. The state Department of Conservation and Natural Resources (DCNR) plans to spray pesticide from helicopters across 26,500 acres in Northumberland County and five other counties beginning next week, but almost wholly in state forests and game lands. Private landowners in the region are on their own this spring. Requests to spray private grounds must be made of the DCNR one year ahead, and a spokesman said he wasn't aware of any approved in Northumberland County for 2015.
The caterpillars crawl on trees, across grass, along fences, windows and siding. They migrate in the wind, a stiff breeze carrying the bugs on silken threads.
Larvae will mature by mid- to late-June, enter pupation and emerge as moths in mid-July. It's the culmination of the species' life cycle, and the shortest period - the insects survive as moths about one week.
The gypsy moth are often confused with tent caterpillars, according to Terry Brady, DCNR's deputy press secretary. The tent species nest in a structure after their namesake, spread between tree limbs. Gypsies nest in small egg-like structures affixed to timber.
Brady likened gypsy moth populations to a thunderstorm, heavy in pockets across a wide area. Overpopulation may be their own demise.
"If the population is so heavy and so dense, they actually normally collapse themselves," Brady said.
A mild, wet period could do the trick in taming the population, too, as fungus is an enemy.
"This is shaping up to be a busy year," Brady said.