Tree-of-heaven and lantern flies

Question: I'd like some advice on how to address SLFs on a tree-of-heaven in our yard. We are now doing what we can to kill the flies, but would like some advice on options for removing the tree-of-heaven. I understand that the tree itself may need to be treated first to ensure that the removal will address the problem.

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied August 21, 2024, 9:53 AM EDT
response: You definitely want to remove the tree but it will take a little work to do that effectively. If just cut down, Tree-of-heaven will continue to re-grow from the roots that are still alive. The best option for a tree that size is to use the "hack and squirt" procedure. The links below will show you what this is and tell you when is the best time to apply it.  The third link below is information on the SLF itself and how to control it. Please note that we don't believe using insecticides would be effective. Removing its primary food source, is the best first option.  Let us know if you have any other questions. Robin  https://extension.umd.edu/resource/tree-heaven/  https://www.allianceforthebay.org/2018/08/tree-of-heaven-a-devilish-invader/  https://extension.umd.edu/resource/spotted-lanternfly-home-gardens/

responder: The Question Asker Replied August 21, 2024, 10:20 AM EDT
response: HelloI do have one other question. We’ve been trying to get rid of the flies. Spraying with vinegar has been recommended but all that did was get the flies to climb higher in the tree. Any ideas to help with that? It’s impossible to reach them now with the sprayer we have. Or do we just need to wait it out until we can remove the tree after the poison does its job?On Aug 21, 2024, at 9:53 AM, Ask Extension wrote:﻿

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied August 21, 2024, 10:35 AM EDT
response: The Spotted Lanternfly in Home Gardens web page that Robin linked to includes low-toxicity insecticide options like horticultural oil and insecticidal soap. That said, we do not recommend any insecticide be used to control them, as it won't work very extensively (it won't notably reduce the area population, and they can easily jump or fly out of the way of a spray) or for very long per treatment (which is why they are less of a risk to beneficial insects). Vinegar is not a pesticide, except when it is used to treat weeds, and in those instances, it is a much stronger and caustic concentration of acetic acid. Since acetic acid can thus be an herbicide, we do not recommend using it to spray plants. The best approach is to just wait for an herbicide-treated Tree of Heaven to succumb to treatment and then be cut down. It won't get rid of all lanternflies, but they may disperse on to other plants and in most cases won't congregate as heavily in one spot as a result.  Miri

responder: The Question Asker Replied August 21, 2024, 10:58 AM EDT
response: Thank you for the information. I was afraid of that - that the best plan would have to be long term, given the nuisance they’ve become with the honeydew over the car and other nearby buildings. But I get it. That’s why we hope to manage them in Maryland. Thanks again On Aug 21, 2024, at 10:35 AM, Ask Extension wrote:﻿

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied August 21, 2024, 11:01 AM EDT
response: You're welcome.