Yellowingon spicebush

Question: Hello I have been noticing yellowing on the leaves of spicebush Lindera benzoin at the nature center where I work. I did some research and found pictures that look similar (attached are ones I took) caused by  Lindera Emaravirus. The information I found said it could only be confirmed by sending a sample to a lab? However it seemed the only treatment was removing infected plants? On our 200 acres we probably have tens of thousands of spicebush - it is the main understory plant as grew before the current deer pressure so removing isn’t practical and would completely alter the woods.  Do you know if it kills spicebush? Recommendations?
Worried Clare

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 May 09, 2023, 11:50 AM EDT
response: Hello Clare,  These symptoms do appear to be viral, but the only way to be certain is to test samples in a plant diagnostic lab, as a variety of causal agents can mimic the damage a virus can cause. We are inquiring with one of our plant disease specialists to ask if she agrees this looks viral and to see if she is able to test samples; we will get back to you once we have her feedback. (It might take a few days.) Plant viral infections are incurable and tend to be spread by sap-feeding insects, but it's not necessarily something that requires intervention as there are a huge number of plant viruses and many are likely native to our region and a natural part of the ecosystem so they don't cause widespread habitat degradation. That said, it's not uncommon for individual virus-infected plants to decline and eventually die, though some viruses cause more detrimental symptoms than others. For now, until we determine if sample testing would be beneficial, you don't need to take any action; if we do determine it's likely virus but don't need to test the plant, at that point you can remove it if desired and dispose of the debris. If testing is suggested, we'll pass along instructions about how and where to send samples.  Miri

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 May 09, 2023, 12:28 PM EDT
response: Hi Clare,  We have an update as we've already received a reply to our inquiry. Our pathologist agrees that this is most likely the emaravirus that infects spicebush. She's seen it in native spicebush plantings in central Maryland as well as in nursery plants. She does not have the ability to test samples for this particular virus, but she says the symptoms in the photos are typical for this disease. Fortunately, for several reasons she would not be concerned about it: it's not brand-new to our area, the symptoms usually diminish in the summer when temps. are highest, and it does not seem to kill the infected plants. You can still remove this lone plant if you prefer, but no other action is needed to protect the understory layer in the center's woodlands.  Miri

responder: The Question Asker Replied May 09, 2023, 12:43 PM EDT
response: Thanks looking forward to see if we can get a sample tested - a quick look around our spice bushes showed several hundred with the same symptoms just in the small area I checked so removing isn’t an option unless they die. Thanks Clare Sent from my iPhone On May 9, 2023, at 12:28 PM, Ask Extension <<personal data hidden>> 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 May 09, 2023, 1:42 PM EDT
response: Our plant pathology lab is unable to test for this virus (special supplies are needed to screen for every virus type) and testing from any other lab capable of doing so might be cost-prohibitive as testing is not inexpensive, plus it requires a minimum amount of plant material harvested from every plant being screened. Since our pathologist has said that this particular virus has not caused catastrophic problems in our environment, nor does it seem to kill infected plants, no action should be necessary to attempt to eradicate it. (Besides, sap-feeding insects could always re-introduce it again in a future year from other sites within or outside of Maryland.) Having a diverse woodland plant community is the best defense against habitat degradation, and in many cases that is best accomplished by removing invasive species where possible (allowing native species to recolonize the site on their own) while excluding deer, since they often preferentially feed on native plants while ignoring the invasives. We acknowledge that the exclusion of deer from a site of this size, especially since it's a nature center, is probably not feasible or practical. Spicebush is so common in our woodland understories in Maryland that, even if the population declines temporarily in the center's woods, it probably won't have much impact on the fauna in the area overall.  Miri