Jan 28, 2015Anatomy of a new pest battle
FGN assistant editor Gary Pullano is blogging from the 2015 Mid-Atlantic Fruit & Vegetable Convention in Hershey, Pennsylvania.
The manager of Pennsylvania Department of Agriculture’s (PDA) entomology program is optimistic a new invasive pest discovered during last year’s growing season at a Berks County specialty stone company that imports product from Asia could be eradicated in short order – if containment strategies are swift and effective.
Sven-Erik Spichiger confirmed for a Tuesday educational session audience at the Mid-Atlantic Fruit & Vegetable Convention that spotted lanternfly has the potential to impact the grape, fruit tree and hardwood industries.
He indicated the department is getting ready to announce a tree banding program using sticky tape rolls in the infected area and possibly elsewhere to help control its spread and kill the pests.
The finding of the pests prompted the immediate quarantine of Pike and District townships, according to PDA.
“This is an early, relatively contained detection,” Spichiger said.
The inch-long, black red and white spotted pest, is native to China, India, Japan and Vietnam. It’s an invasive species in Korea, where it has attacked 25 plant species that also grow in Pennsylvania, according to PDA.
“Grapes and peaches are important to our economy here in Pennsylvania and elsewhere,” Spichiger said. “We’re trying to make a stand on this. (Eradication chances are) the best I’ve ever seen. They’re confined to 40 kilometers. It’s small – if we can jump on it we can knock it out. I’m not telling you it’s the next (brown marmorated) stink bug yet. “It’s one of the worst pests ever introduced. We’ve only known about it a few months.”
The spotted lanternfly, Lycorma delicatula, attacks grapes, apples, pines and stone fruits. It often attaches to the bark of Tree of Heaven – sometimes referred to as Paradise Tree – an invasive species similar to sumac that can be found around parking lots or along tree lines. Adults often cluster in groups and lay egg masses containing 30 to 50 eggs that adhere to flat surfaces, including tree bark.
Freshly laid egg masses have a gray, waxy, mudlike coating, while hatched eggs appear as brownish seedlike deposits in four to seven columns about an inch long. Trees attacked by the spotted lanternfly will show a gray or black trail of sap down the trunk, according to PDA.
“The honey mold is so bad from the trees (in the infected area) it feels like you’re getting rained on,” Spichiger said.
Spotted lanternfly cause a lot of damage to trees, including Ailanthus trees that are prevalent in the area of the pest’s discovery in Pennsylvania.
The stone company imports stone from China, India and Brazil.
“These guys have bent over backwards to try to fix the problem,” Spichiger said regarding the stone company, including providing building space for a pending USDA evaluation of the finding.
He said the infected trees are characterized by a “strong smell of rotting vinegar,” attracting a large amount of bees.
“You don’t just have honeydew being shot out of back of the adult insect. There’s seeping and bleeding coming from the trees and coalescing at the base. They’re capable of piercing any tree we saw there. There’s quite a good trail of sap coming out, with a huge mass of sap built up at the bottom of tree.
“It’s not too hard to imagine such a wound on a freshly planted row of grapes. A couple adults feeding on grapes could be a bit of a problem,” Spichiger said.
“This is not a pest anyone was looking for – including at the ports. It was really easy for it to get here. In South Korea it is considered an invasive pest and impacts grapes and peaches.
“What we’re hearing from South Korea is, if you remove trees from area, they might move to grapes and peaches first as they love them, too. There’s about 65 other things they could impact. In the late fall, we saw it feeding on weeping willow.”
Spotted lanternfly narrows its host range before mating to the preferred host – in this case Ailanthus trees. “It’s seen (in foreign countries) on over 65 different plants, including hardwoods, ornamental trees, fruit trees, vines.
“Is this just an occasional visitor? Right now it’s not known. In the literature, when adults are getting ready to mate, they go to tree with high sugar content, like our sugar maple in Pennsylvania. It’s not been tested in South Korea for that. It has a life cycle of one year and overwinters in a foam-covered egg mass, with 30 to 50 eggs in each mass.
“We’re having people be very careful about how they move things like timber, firewood – that’s key to helping stop this. Egg masses can be laid on trees or any smooth surface.
The stone company’s employees have been trained to detect the egg masses.
“They’ve been all over it. They engaged in a compliance agreement with us. They are really cooperating and going the extra mile. They give us their shipping records – no question asked, so we can investigate those sites as well. They’ve been very cooperative.”
He said the immature stage of spotted lanternfly could hatch in May in Pennsylvania.
“The cold winter should have killed them all last year – obviously it didn’t,” Spichiger said.
“Lab trials have shown a January with 11 degrees normal average temperature should do it, but that doesn’t account for finding them under rocks and trees.”
Because the pest migrates up and down trees or plants each day, they are active hoppers and tree bands are effective in catching them.
“There are some fungus treatments that could work, but they are not labeled to use anything against this pest. There’s no magic bullet spray recommendation. It’s something to evaluate and that takes time. If you think you have problem with these, we’re going to recommend tree bands for this spring.
Adults could emerge as early as July into late summer, when they feed, mate and lay eggs. In South Korea females lay eggs twice before dying. Males and females mate multiple times. We do have an established population. – we have quite a few.
As part of a “rapid response effort,” a new pest advisory group was formed, with a technical working group being part of it. A delimiting survey was implemented, quarantine put in place (similar to a gypsy moth quarantine already in place).
Ports were notified, which led to a discovery to an adult specimen in Chicago.
The shipments of products by the stone company outside of the area were investigated; all being negative thus far.
The delimiting survey confirmed the heaviest infestation at the original site grids.
“They have a very confined area,” Spichiger said. “Grids are 1 kilometer by 1 kilometer and there’s 40 of them. We can wipe that out fairly easily. It is a challenge because it’s a rugged area. It’s not insurmountable. We have seen infestations larger than this wiped out, including the European grapevine moth which is not in California any more. Things can be done.”
There is “a factor of time associated with this,” Spichiger said. “The Koreans indicated it spread in three years. We suspect it’s been here for two. We want to reduce the core area. “We don’t have five or six years to think about what we’re doing.
“Something to keep in mind is we’ve inspected many other places with no additional sites detected,” he said. “It’s a very small, localized infestation. We’ve had vineyards and orchards in the area inspected. No producers are heavily infested yet. Most grape producers are extremely concerned and wish to assist in any way.
Spichiger said the aspects of a successful eradication will include establishment of a North American Host Range; and determination of cold tolerance, pesticide efficacy, commercial crop control measures, seasonal occurrence data, native parasite potential, environmental impact, development of monitoring tools and egg mass mitigation methods.
“The community and industry have been extremely cooperative,” Spichiger said. “The federal response has been great. USDA is coming through with researchers to do it. The approach is multifaceted, including quarantine, chemical control, mechanical control, education and community involvement. No one thing is going to kill them.”
“If we can get the community to band trees on their property, we can actually keep this at bay until more permanent solutions come along.”
Updated information can be found here.