MONDAY, DECEMBER 9, 2024. BY STEPHANIE BOLTON, PhD, LODI WINEGRAPE COMMISSION.
Featured image of spotted lanternfly nymphs and egg masses on a tree, courtesy of USDA APHIS.
Thanks to our National Grape Research Alliance membership, we were lucky to host Dr. Julie Urban from Penn State in Lodi the other week to talk about the spotted lanternfly and the Tree of Heaven, a special host for the invasive insect which offers it a competitive advantage in our ecosystems. If you aren’t up to speed about the potential threat the spotted lanternfly poses to California agriculture, fill up your coffee mug and read our earlier blog post HERE to catch up.
Dr. Urban – holder of not one but two PhD’s – patiently and thoughtfully answered our many questions for hours. She was even game to drive around the Lodi AVA in the rain to experience the diversity of our vineyards and learn about California viticulture firsthand. Dr. Urban is the ideal type of researcher for growers like us to collaborate with as she is smart, practical, curious, humble and really good at what she does. She is also an excellent listener which is one of the more under-rated qualities of a successful researcher.
We learned three important *new* pieces of advice from Dr. Urban that are crucial to our California prevention strategy for the spotted lanternfly (CDFA, County Ag Commissioners, Growers, Truck Stops, Railroads, Caltrans, and PG&E Tree Removers – we hope you are paying attention!):
- When new spotted lanternfly infestations have been discovered in the Midwest and on the East Coast (typically at truck stops or other transportation hubs), there are always also one- to two-year old egg masses present on the Trees of Heaven. This means that just like with vine mealybug infestations, it takes us humans one or two years to observe the presence of the insect after it has already been there.
- TAKEAWAY ACTION: Inspect all Trees of Heaven for egg masses NOW, during the winter months when they are easier to find as the leaves drop. Look all over the tree and especially as high as you safely can.
- There is a short window of time (possible one or two years) when the spotted lanternfly population seems to stay close to a new infestation area and does not spread out much from there.
- TAKEAWAY ACTION: If we act NOW to inspect the trees, we can delay further movement of the insect and reduce future potential damage to our crops. Remember, prevention is always the cheapest and smartest part of IPM.
- When there are several trees present, the spotted lanternfly may prefer one tree over the other trees.
- TAKEAWAY ACTION: We need to inspect ALL Trees of Heaven that we encounter, not just one tree out of a grouping.
The spotted lanternfly will lay eggs on trees other than the Tree of Heaven, but the Tree of Heaven in particular is a preferred host for the insect and the Tree of Heaven’s unique ability to grow in otherwise inhospitable areas along transportation routes make it an ideal target for hunting for egg masses during this prevention stage.
Eager to get started on these action items, right after our discussion with Dr. Urban at the Lodi Winegrape Commission headquarters we hopped into Chris Storm’s truck and started driving around. We did not find any spotted lanternfly egg masses in Lodi but only made it to a few trees before we got excited to see the salmon spawning at the Mokelumne River and hungry for lunch.
Dr. Julie Urban (left) with the author, Dr. Stephanie Bolton, in Acampo hunting for spotted lanternfly egg masses on a Tree of Heaven. Photo by Chris Storm. Also present was Dawson Lewis, the Lodi Winegrape Commission’s Research, Education and Communication Committee Chairperson.
Spotted lanternfly egg masses look like dried mud or cement and vary in size, although according to the City of Philadelphia website they are typically one inch long by three quarters of an inch wide. They can range from light gray in color to dark brown, and can be easily looked over as part of the tree’s bark or a lichen. You can search for them year-round.
Above photo showing a person pointing to a spotted lanternfly egg mass, courtesy of USDA APHIS.
It’s imperative to note that you, whoever you are reading this article, do not wait around for someone else to inspect our California Trees of Heaven for the protection of your crop and livelihood. No one else is doing it for you and these trees are literally everywhere so we need all the help we can get. Likewise, you should not wait around to tell the owners of truck stops or your Ag Commissioner’s Office or your neighbors about this issue. No one is telling them on your behalf. It is up to us. Share this article and do your part today.
As with our grapevine virus challenge, the state of California does not have a robust network of people working to holistically manage the prevention of the spotted lanternfly by inspecting (first) and properly removing (second) the Tree of Heaven. It is up to us to protect our livelihoods and do what is within our power right now.
For more information on how to identify and properly remove the Tree of Heaven, which is destructive in its own right regardless of the spotted lanternfly, click HERE.
If you find a spotted lanternfly egg mass, call the CDFA hotline immediately at 1-800-491-1899.
This information was also shared at our monthly IPM Network Breakfast Meeting on December 3, 2024. These meetings are open to all and occur on the first Tuesday of every month at Burgundy Hall in the Lodi Grape Festival Grounds. They serve as a place to share current IPM information with our winegrowing community and those that support us. Please consider attending to stay abreast of current issues, challenges and opportunities. These IPM meetings are listed on our Calendar linked above.
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