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Bug of the Week is written by "The Bug Guy," Michael J. Raupp, Professor of Entomology at the University of Maryland.

The next invader: Spotted lanternfly, Lycorma delicatula


Spectacularly beautiful but nonetheless pests, spotted lanternflies have arrived in the United States.


In what has become a never ending stream of invasive species arriving in the US, last year witnessed the detection of yet another insect pest in Berks County, Pennsylvania, a new home of the spotted lanternfly. This area was made famous with the arrival of an invasive species two decades ago when neighboring Lehigh County registered the discovery of the infamous brown marmorated stink bug, a pest visited in several episodes of Bug of the Week. The spotted lanternfly, which is actually a planthopper, not a fly, is a relative of lanternflies we’ve met before in Bug of the Week (Rain on a sunny day: Lanternflies, Fulgoridae). Presence of this nocent species was confirmed in early autumn of 2014 by the Pennsylvania Department of Agriculture working in collaboration with the Pennsylvania Game Commission. How it arrived in the US is not clear, but like many recent invaders, this one appears to be a good stowaway.

The female lanternfly deposits eggs in rather nondescript batches of 30 – 50 cloaked with a waxy cover that turns brown or gray with age. These egg masses are often laid on tree trunks, but have also been discovered on substrates including stones, vehicles, and lawn furniture. It is easy to see how this bug might have arrived undetected with a shipment of goods from a foreign land. China is the aboriginal home of the spotted lanternfly and it was detected in Korea in 2006, where it has become an important pest of many fruit bearing woody plants including grapes, apples, cherries, peaches, and more than 70 other ornamental species such as evodia, lilac, maple, and dogwood.

It’s easy to see how the non-descript egg masses of the lanternfly sneak past human detection and move about the world.

In Pennsylvania eggs hatch just about this time of year, in April and May, and the tiny nymphs insert their sucking beaks into leaves and stems and feed on the nutrient rich phloem tissue. Feeding by nymphs and adults robs the plant of valuable nutrients and as a byproduct of their feeding, large quantities of sugar-rich honeydew are produced. As we’ve seen in previous Bug of the Week episodes, with some aphids (A sweeter side of aphids) and soft scale insects (There's a sucker born every day - Tuliptree scale) the waste product honeydew serves as a substrate for the growth of sooty mold, a non-pathogenic fungus that stains the plant black, impairs photosynthesis, and disfigures fruit and leaves.  Nymphs feed and shed their skin several times during the course of development over the summer. By late summer they complete development and molt to the adult stage. Males are slightly smaller than females, which average about an inch in length. After mating, females deposit eggs on a variety of surfaces until the cold winds of late autumn bring an end to the growing season.   

What has been done to stop the spread of this pest? At present, a quarantine has been placed around several municipalities in Pennsylvania, including Bally, Bechtelsville, District, Earl, Hereford, Pike, Rockland and Washington. This quarantine restricts the movement of “any living stage of the lanternfly, brush, debris, bark, yard and landscape waste, remodeling or construction waste, logs, stumps, or tree parts, firewood, grapevines, nursery stock, crated materials, outdoor household articles including recreational vehicles, lawn tractors and mowers, mower decks, grills, grill and furniture covers, tarps, mobile homes, tile, stone, deck boards, mobile fire pits, any associated equipment and trucks or vehicles not stored indoors” (excerpted from  Spotted Lanternfly, Pennsylvania Department of Agriculture). Delimiting surveys are underway to determine the spread of the bug and attempts will be made to eradicate the pest where it is found.

What can homeowners do if they suspect they have this pest? The Pennsylvania Department of Agriculture has established a remarkable web site (link provided below) to assist citizens with identification of this new pest, how to destroy egg masses, and how to report sightings. In an ever-changing world where a global economy has resulted in a global biota, let’s hope that the genie in Berks County, Pennsylvania doesn’t escape from the bottle.


Bug of the Week thanks Sven-Erik Spichiger for providing the inspiration for this episode with his recent stellar presentation on this beast at the 86th Annual Meeting of the Eastern Branch of the Entomological Society of America. To learn more about other invasive species such as emerald ash borer, Asian tiger mosquito, brown marmorated stink bug, and other noxious insects and arachnids, please listen to the Kojo Nnamdi Show at WAMU from Monday, May 18, 2015 to hear a live interview with the Bug Guy. 

To learn more about the spotted lanternfly, please visit the following links: