Among the ton of nature-related email I normally get, this past week I received news of yet another exotic Asian bug that could threaten our crops and native ecosystems and of a new guide for identifying native shrubs and vines.
Spotted lanternfly invades
Friends, family, colleagues in the conservation community and readers of this column helpfully send me their nature observations or news about some natural phenomenon, and last week was no different. Among the more interesting emails I received was a link from my brother to an article on the Pennsylvania Department of Agriculture website about an invasive pest from Asia that had been spotted there. Keeping in mind that the brown marmorated stink bug (BMSB) was also first reported in Pennsylvania several years ago, I cringed at the thought that hoards of yet another foreign invader would be heading our way.
The bug, first reported in September, is the spotted lanternfly (Lycorma delicatula). Native to China, India, Japan and Vietnam, this insect has the potential to affect grape, fruit trees, pines and hardwoods, the PDA article says. More than 70 other plant species could also be attacked.
About an inch long, with its wings folded the spotted lanternfly looks more like a cicada than a fly. It is, in fact, in the same insect order as cicadas (Hemniptera), rather than true flies (Diptera). In looking at the photos, I couldn’t help but think that this was one strange but beautiful bug. Having the head of planthopper, the superfamily to which it belongs, its wings are what to me are truly gorgeous. With its wings closed, the fine bars and black spots against a white background are lovely, but it’s when the bug spreads its wings that its true sartorial splendor is revealed, with patches of red, spotted with black, on the hind wings. Even the nymphs, about the size and shape of ladybugs, are pretty, with white or red spots against a black background.
As with many insects that have invaded from Asia, including the BMSB, the spotted lanternfly is often found on ailanthus (tree of heaven), another Asian native, says PDA. The stink bug showed up at my house this fall in much smaller numbers than last year. Likely general dispersion of the stink bug — along with possible effects on local populations from this year’s cool, damp weather — accounts for the lower numbers.
Like the BMSB, the lanternfly doesn’t cause big problems in its own native ecosystem but could wreak havoc in ours, and in agriculture here. According to PDA, it is an invasive species in Korea, where it has attacked 25 plant species that also grow in Pennsylvania. The department has quarantined parts of Berks County, where the lanternfly was first discovered. Anyone spotting the bug here in Virginia, should it escape the Pennsylvania quarantine, should contact their local office of the Virginia Cooperative Extension.
VDOF publishes shrub and vine guide
On the good news side, I also received a news release from the Virginia Department of Forestry about an identification guide that it has just published, “Common Native Shrubs and Vines.” This is a companion to “Common Native Trees of Virginia,” the tree ID guide VDOF published in 2007 that is arguably the best guide to local native trees.
These guides are 5.5 by 8.5 inches and around 120 pages long. While not exactly pocket sized, they are small and light enough that they can easily be taken into the field. Both guides are also downloadable from the VDOF website (search on the title), or hard copies can be ordered through the website for $3, or a combo pack of both guides for $5, plus shipping. These are a huge bang for the buck.
The new guide “features descriptions, line drawings and identification keys to 66 of the most common native Virginia shrubs and woody vines” and “hints for effective plant identification.” As with the tree guide, the new guide also includes some important nonnative species that are invasive, information about where to go to study plants and other resources.
I’m waiting to get my hard copy to really give it a workout in the field, but looking through the PDF of it that I downloaded, I found it to be similar in format to the tree guide, with the aforementioned key (decision tree) to lead users to the correct plant, and useful write-ups about each species.
This summer I noticed that vines seemed to be growing faster, with new ones popping up in unexpected places. Friends in the conservation community had similar observations. At the edge of the forest surrounding my house, grapevines seemed to be taking over, oriental bittersweet (which had appeared for the first time last year) and honeysuckle had spread and honey vine (in the milkweed family) had appeared for the first time. Poison ivy, common throughout the Blue Ridge and Piedmont, seemed also to be thriving. The rainy summer undoubtedly contributed to the lush growth of vines, as well as foliage of other plants, but the rise in CO2 may also be having an effect (see sidebar below).
I had already planned to dig more into the issue of rampant vine growth next spring, so publication of the new VDOF guide is especially timely for me. Although tree-identification books and apps are readily available, ID guides for native shrubs and vines are not. I heartily recommend this one to anyone who wants to identify vines on their property, especially nonnative exotics, before they take over.
© 2014 Pam Owen
Vines, even native ones, can overwhelm a forest, as I was recently reminded when I drove over Massanutten Mountain on U.S. 211 and viewed the kudzu that had taken over there in recent years. In 2006 (July 15), The Washington Post reported that “from backyard gardens to the Amazon rain forest, vines are growing faster, stronger and, in the case of poison ivy, more poisonous on the heavy doses of carbon dioxide that come from burning such fossil fuels as gasoline and coal. . . . Complaints about vine infestation have increased tenfold in a decade.”
According to an article the following year on the University of Ohio website, researchers studying growth of vines in two bottomland forests in South Carolina found “up to a 10-fold increase in the number of vines in just two decades.” These vines include grapevines, trumpet vine, poison ivy and Virginia creeper, and most use adhesive roots or tendrils to climb trees.
“Many vines thrive on elevated levels of carbon dioxide,” Bruce Allen, the study’s lead author, is quoted as saying in the article. “Several studies suggest that vines like poison ivy benefit more than other plants from higher CO2 levels.”
In a previous study, Allen and his research colleagues suggested that increased vine growth equates to a decrease in tree growth, the article says. Many factors can affect vine growth, and research continues on the role CO2 plays.