Update on Spotted Lanternfly

Hello, everyone, It's time for an update on spotted lanternfly (SLF), as it continues its spread through the state. After the discovery of SLF in Winchester in 2018, a quarantine zone was erected - the insect was first found in Winchester and Frederick County, but as it spread, the quarantine zone included, in addition to those areas, Clarke and Warren Counties. In 2022, the zone was significantly expanded to include Albemarle, Augusta, Carroll, Nelson, Page, Prince William, Rockingham, Rockbridge, Shenandoah and Wythe Counties, plus the cities of Buena Vista, Charlottesville, Harrisonburg, Lexington, Lynchburg, Manassas, Manassas Park, Staunton and Waynesboro. The map of the quarantine zone is here:

The disjunct part of the range, in Wythe and Carroll Counties (near the North Carolina border), is almost certainly due to human-assisted transport. The site in Carroll County is near a parking lot at the junction of I-77 and Rt 58. A notable new find late this season was in the New River Valley, in the city of Radford (this does not yet show up in the quarantine zone - there is always a lag in the quarantine map because of administrative issues in expanding a quarantine zone). Dead adults were found at office windows across the street from private land with tree of heaven. The discovery was aided by spiders, whose webs on the window sills ensnared the adults!

At this time of year, SLF is in the egg stage. Eggs are laid not only on tree of heaven, but the bark of other trees, as well as inanimate objects. In vineyards with established populations, egg masses may be seen in high numbers on trellis posts. In one vineyard in northern Virginia, masses were seen in high numbers on treated wood end posts, shown here. Note how the presence of protective covering over the eggs deposited by the female varies from complete to absent.

One troubling observation was the concentration of egg masses in the inner (concave) surfaces of roll-formed steel trellis posts. This protective behavior will likely result in difficulties in achieving spray coverage with the development of effective ovicides. See the video here.



There will be further updates as this pest increases its presence in Virginia. More later, Doug P.