Watch Out for Spotted Lanternfly!

I recently attended a workshop focused on early detection of Spotted Lanternfly (Lycorma delicatula) (SLF) in Fairfax County. Speakers represented the Virginia Cooperative Extension, the Virginia Department of Forestry, and the Fairfax County Urban Forest Management Division.

Spotted Lanternfly is native to China, and has also been found in India, Vietnam, and Japan. Introduced in Korea in 2006, it is considered a pest in that country. The insect was first detected in the US in September 2014, in Berks Country, Pennsylvania, where it was likely imported as egg masses laid on landscaping stone. The first Virginia populations were detected in the Winchester area last year.

Spotted Lanternfly Adults
USDA photo by Lance Cheung

A hemipteran insect, L. delicatula is highly invasive and can expand its range rapidly; it can use at least 70 North American host species, although it has a particular association with Tree of Heaven (Ailanthus altissima). A phloem feeder, the lanternfly sucks sap from its host plant, leading to wilting and reduced photosynthesis. Spotted Lanternfly also exudes honeydew, which promotes the growth of sooty mold, further impairing the health of its host plant.

Because its American hosts include species of grapes, hops, stone fruits, and Malus, the threat of significant economic losses looms.

Egg masses are laid on the roughened, brocaded bark of A. altissima, other tree species, and even weathered stone, concrete, and metal. Spotted Lanternfly undergoes incomplete metamorphosis, the eggs hatching into nymphs that go through several instars before transforming into winged adults. It is conjectured the lanternfly extracts and isolates toxins from its ailanthus host, and hence that the bright red coloration of its later instars and adults constitutes aposematic coloration. The adult, about an inch long, resembles a colorful black-brown-and-red moth.

In Virginia, first instar nymphs for this season were observed on April 26, 2019. If you see an egg mass, nymph, or adult that you suspect to be Spotted Lanternfly, please report it to the Virginia Cooperative Extension at https://ext.vt.edu/spotted-lanternfly.

First instar Spotted Lanternfly nymphs on Fox Grapes by Rkillcrazy

First instar Spotted Lanternfly nymphs on Fox Grapes
Photo by Rkillcrazy license CC BY-SA 4.0

Here in Fairfax County, foresters hope to monitor possible sites where Spotted Lanternfly might first appear, and that means monitoring populations of A. altissima, itself a non-native invasive plant species. To recap field identification of this plant, look for compound leaves with 11 to 41 leaflets; each leaflet bears a small “thumb” with glands. Yellowish flowers are borne in panicles; the fruits are yellowish or brown samaras. Twigs are stout and hairless; leaf scars are large and triangular, with numerous bundle scars. When crushed, the plant produces an odor (in the words of Jim McGlone) “of burnt peanut butter.”

It turns out that our map of ailanthus patches in Fairfax county is incomplete, especially on private property. Therefore, please report any Fairfax County observations of Tree of Heaven (Ailanthus altissima) to MAEDN (Mid-Atlantic Early Detection Network), via the MAEDN mobile app or web site.

Tree of Heaven Coming Into Fruit by Luis Fernández García

Tree of Heaven Coming Into Fruit
Photo by Luis Fernández García license CC BY-SA 2.1 ES

By David Gorsline, VNPS Potowmack Chapter Membership Chair and Virginia Master Naturalist

This article also appeared in the Summer, 2019 edition of the Potowmack News.


Editor’s Note: Additional resources about Spotted Lanternfly:

Notes from the Understory

Recreating woodlands in your backyard

Our (under)story
For the past several years, we have been working on a garden inspired by the natural community that might have been here before residential development—probably a Piedmont Oak-Hickory Woodlands. The idea was to use native plants to help support wildlife, from the microbiome all the way up to the neighborhood’s birds and mammals. And that the best way to do that would be to draw on plant communities that were best adapted to the challenging conditions here like the long, hot summers and the shade under several large trees.

Resources
It wasn’t obvious how to narrow this down, but with some help from experts like VNPS Potowmack Chapter board member Rod Simmons, we settled on the Piedmont Oak-Hickory natural community, and then looked up descriptions in studies done by The Flora Project of Alexandria under Rod Simmons here and by the Virginia Department of Conservation and Resources here. There is good intro information at the Plant NOVA Natives website, too. We also spend a lot of time double-checking the Arlington native status of plants at the Digital Atlas of Virginia Flora.

Plants
I am working on a full list of plants we have in our yard, which will have notes on placement, natural habitat, bloom times, water use, etc. This is a work in progress, and draws heavily on some of my favorite websites, including the Digital Atlas of Virginia Flora, Go Botany (has great notes for distinguishing similar plants), the Lady Bird Johnson Wildflower Center, the Missouri Botanical Garden, the Illinois Wildflowers page (search bar is at the bottom), and Native Plants of the Carolinas & Georgia.

May 2018—Rainstruck
The summer plants that seemed cautious about the colder weather in April jumped out within days of the four inches of rain we got in recent days, and have started giving the spring ephemerals some competition.

By Dean Arkema