Invasive Bug Prompts Quarantine In Pennsylvania Townships

The spotted lanternfly has officially arrived in the U.S., and leaders in Pennsylvania are hoping it won't be staying long. The invasive pest poses a threat to fruit orchards and grape vines, along with forests and the timber industry. It was detected in Berks County, northwest of Philadelphia.

"Berks County is the front line in the war against Spotted Lanternfly," Agriculture Secretary George Greig said in a news release. "We are taking every measure possible to learn more, educate the public and ourselves and eliminate this threat to agriculture."

The spotted lanternfly, or Lycorma delicatula, is native to parts of China and eastern Asia. It attacks trees by feeding on sap and harms them further by excreting large amounts of a fluid that coats leaves and stems and encourages the growth of mold, according to researchers.

Pennsylvania announced both the insect's discovery and a quarantine to contain it in a bulletin Saturday, saying that in the U.S., the spotted lanternfly "has the potential to greatly impact the grape, fruit tree and logging industries." The agriculture agency added that along with pines and stone fruit trees (such as peaches), the pest attacks "more than 70 additional species."

When officials declared a quarantine for the Pike and District townships in Berks County, they also urged citizens to help look for both mature insects and egg clusters. Adult spotted lanternflies begin to lay their eggs around September; nymphs emerge in the spring.

The state explains what its action entails:

"The general quarantine of the two townships restricts movement of any material or object that can spread the pest. This includes firewood or wood products, brush or yard waste, remodeling or construction materials and waste, packing material like boxes, grapevines for decorative purposes or as nursery stock, and any outdoor household articles like lawnmowers, grills, tarps and any other equipment, trucks or vehicles not stored indoors.

"Businesses in the general quarantine area need to obtain a Certificate of Limited Permit from the department in order to move articles. Criminal and civil penalties of up to $20,000 and prison time can be imposed for violations by businesses or individuals."

Greig said, "We know we're asking a lot, but we know Pennsylvanians will assist us and help save our fruit trees, grapes and forests."

A research paper about the bug's spread in Korea explains why it can be tough to control:

"Furthermore, no natural enemy of L. delicatula seems to exist in Korea. Thus, farmers use pesticides to control them in vineyards (Park et al. 2009). However, the use of pesticides kills natural enemies of other grape pests and L. delicatula can repopulate pesticide-sprayed areas from nearby forested areas, which contain suitable host species."

The study's authors recommended using sticky traps at the base of trees that can host the insects.

Here are some of the plants the bug particularly likes, according to the researchers: Ailanthus altissima (tree of heaven), Evodia danielii (Korean evodia), Parthenocissus quinquefolia (Virginia creeper), Juglans mandshurica (Manchurian walnut) and Vitis vinifera (the common grapevine).

Thanks to NPR's Susan Vavrick for pointing out this story.