Elm Seed Bugs and A Follow Up on Watering During Drought

Taun Beddes 0:09

Hello, and welcome back to the homegrown horticulture podcast. We greatly appreciate you listening. I am back with Savannah Peterson who's been taking on lots of diagnostic calls. And Savannah, you've had lots of calls on elm seed bug,

Savannah 0:23

you bet. In fact, in the office we're in right now there's one on the window.

Taun Beddes 0:28

They're all over our offices located in an area that is along the Provo river and some canals. They're wild Siberian elms growing all over the place. Hence, our infestation. I've already done the last few days, picked up and thrown away several of them myself.

Savannah 0:46

If you have any, especially volunteer Siberian Elms, there's a couple other species of elms too. But those are a big problem because they'll pop up everywhere. And these bugs like to live on those. And so if you have any of those in around, these are a bug to look out for.

Taun Beddes 1:03

So what do Elm seed bugs do?

Savannah 1:05

started noticing them around: 2017

Taun Beddes 1:51

That's one of the biggest reasons we've been getting calls is that the album seed bug is getting they are getting into people's homes. And especially if you live in established neighborhoods or along waterways, anywhere that elms are grown especially that Siberian Elm, you are likely to start seeing these show up in your house.

Savannah 2:14

They don't do too much damage to the elm trees themselves. It's mostly a cosmetic problem, like they're not going to kill your own, but they will get into your house and smell so bad and be

Taun Beddes 2:27

they put off a sand or if they feel threatened they put off a scent.

Savannah 2:31

In fact, one of the control things is that you aren't supposed to squish them because they smell really bad when they're squished

Taun Beddes 2:39

people. I think a lot of times their first thing they go to his spray, but we shouldn't really even talk about that yet, because we need to talk a little bit more about what they look like, why they're there, the more knowledge about the pest you have, the easier it is to control it.

Savannah 2:58

They do behave similar to boxelder bugs, but they also look kind of similar, at least in body shape, kind of that oval shape. But the big distinguisher is the color and the markings they have. So um sweet bugs are probably about half the size, maybe two thirds the size of the Box Elder. And instead of the gray and bright orange markings that boxelder bugs have, um, seed bugs are more of a reddish brown, sometimes tan and dark brown color. And if you see triangle patterns, that's pretty clearly an elm seed bug. If it looks like a boxelder shape wise, and it has triangles, it's an empty bucket.

Taun Beddes 3:38

So why are we seeing so many Elm seed bugs right now,

Savannah 3:41

we're seeing them partly because it's just time in their life cycle for them to be out. The trees that they live on are finished flowering and starting to develop those seeds, which is the primary food source for those insects, they're more likely to be out feeding. And also, the other big thing is that since they're an introduced species, and they haven't been here very long, they don't really have any natural predators. So there's nothing to really keep the population down.

Taun Beddes 4:06

What are some suggestions about how to keep them out of your house.

Savannah 4:11

There's a few really easy things. The first one that I would say would be to remove their host trees if you can, if you have items that you're not very attached to try planting something else and these won't be in your space as often. The other few are, make sure that you bug proof your house so seal up any cracks, especially around windows and doors, put in weatherstripping if you can use caulk around windows to really seal it up. Those are big things, repair any screens that are damaged, any foundation cracks to all of those, you really want to make sure that there's no entry way for them to get in. Some other control methods that you can do if they are around your house are if you have a vacuum with a hose on it. One fun trick is that you can get like a nylon stocking and stick part of it into the vacuum, put it around the hose so that there's an opening right there, vacuum up all these bugs. And then once you're done, just pull the nylon out, tie it up, throw it away, and it's a pretty good way to keep them contained. If you happen to have a shop vac, then even more efficient way to take care of them is to put about an inch of water in the bottom of your shop vac, maybe a dash of dish soap, which isn't an insecticide in itself, usually, but it'll make them drown a little faster. And then just vacuum those up, empty out your shop back into a garbage can, and it'll take care of them.

Taun Beddes 5:38

I like those suggestions, I would say that if you are going to use the nylon sock trick, where you're inserting that into the hose, make sure that nylon sock is secure with maybe even something like duct tape so you don't suck it into your vacuum and ruin something. Yeah, it does work if you have a vacuum that you can do that with but be careful with that method. Another thing with elden seed bug is that people want to control them outside, which is much more difficult because they fly and so you can't oftentimes spray them on the elm trees and the linden trees because especially the elms can get up to 50 feet tall, and it's just really impractical to spray. So one thing that we recommend doing is if you see them congregating on the side of a building is using a spray such as horticultural soap, to kill them. The horticultural soap isn't an internal poison. It's just more of a contact poison. And so it's going to be fairly when I say earth friendly, I guess I should say read reduced risk. But one thing that you can do that is reduced risk is to spray them with the horticultural soap. if you find them congregating. So there are a number of other insecticides that are registered for them. The the pyrethroids, so bifenthrin, permethrin, a lot of those that are registered for spraying around the foundation on buildings. There are several available from local garden centers. But we would highly recommend trying the horticultural soap just because the pyrethroids can do a lot of damage to insect predators, and flare things like spider mites, which you don't want becoming a problem.

Savannah 7:28

they really aren't going to do any damage to your tree, they'll live there, they'll eat a little bit, but they aren't going to hurt it. And they aren't known to carry any kind of diseases or bug humans or pets or anything. They're just a nuisance pest because there's so many of them. So they're not really dangerous. They're just annoying. It's worth starting with the least dangerous, or least toxic methods of control. So any of the things we mentioned, like the vacuuming and filling your house would be good places to start, move on to the horticultural soaps. And then if there's still a problem, move on to the stronger chemicals.

Taun Beddes 8:04

So one of the control methods we mentioned earlier was to cut the trees down. And that advice stands but we are also not dumb. And I don't want a lot of people saying you're stupid, you said to cut down my 50 foot trees, I realized that that may not be practical for everyone. So with that being said, the Elm seed bugs are probably just going to be a part of life. Use these control methods that we've mentioned. I hope over the next several years that we do get natural predators and maybe some pathogens that will reduce the numbers. that often happens. Sometimes it doesn't. So LMC bugs are here. And thank you again.

Maria 8:43

On this morning wanted to start the show talking about something that it's definitely on everyone's mind. And that's the drought and on different things that we can do really to help out our moms and our trees and our bushes with so little water.

Taun Beddes 8:56

We really have been getting tons of questions about this, you know, how do I keep my lawn alive? And you know, how often should I water? And so we decided to have Dr. Kelly Kopp, who is an Professor within USU extension, then she does extension water conservation, and is our turfgrass specialist,

Maria 9:17

Dr. Kopp. Thanks for joining us this morning. Thank you very much for having me. Let's start out with our grass. How do we keep it alive while it's dormant? I mean, how much water does it need yet? fill us in on some tips.

Kelly Kopp 9:31

Well, there's some really good news on that front, I would say and it's it's something that I think a lot of folks aren't necessarily aware of. But the grasses that we grow in Utah are quite resilient. They're quite strong, even in the face of the heat that we're having and the current drought. And so even if you were only allowed to give our grasses the bare minimum of water, they could survive and you mentioned dormans dormancy, which I hope will do discuss more, but they can survive in dormancy with as little as half an inch of water per month. So the the recommendations that are coming from the state and from the division of Water Resources right now, which are indicating that irrigation should be restricted to twice per week are more than adequate to keep our grasses alive even as they're entering dormancy right now because of, of drought, yes, but also at this time of year, it's really more a response to heat.

Taun Beddes: 10:30

So can you describe the difference between what people assume as dead and dormant turf?

Kelly Kopp: 10:36

Sure, so the thing and it's it's really timely, because this time of year, I always get a lot of questions, I get a lot of very concerned folks asking me what to do because their grass is, quote, unquote, dying. But usually what they're seeing is grass going off color. And by that I just mean going yellow, or perhaps maybe yellow with a little bit of a brownish tint in the leaves. And that is the key distinction between dormant and dead turf grass. So dormant turf grass, the leaves can go off color, as I mentioned that yellowish color. But they do that in order to protect the growing point of the grass plant, which is actually right at the soil surface, very small, and so not usually visual visible that is unless you go digging for it. But the grass plant is essentially sacrificing the leaves so that it can maintain that growing port or crown of the plant. And so if you were really concerned, and again, I think people just aren't necessarily aware how tough our grasses are. But if you were very, very concerned about telling the difference between dead and dormant turf grass, you could dig down to the soil surface and have a look at the growing coordinates of the grass plant and there will still be quite moist and perhaps have a little bit of green color, which indicates that the grass is still alive. So I think that as I've been traveling around the state in the past weeks and working with various folks in organizations, I've seen a lot of grass going dormant, which is wonderful. I want to give utahns a pat on the back for that because this year, I'm seeing that more than I have in any other year before and I think people are really responding to the request to say water. But again, if they're concerned about that, they can check at the soil surface, the crown of the grass plant and see that it is still alive. And what will happen is as our temperatures cool into the late summer and fall, the grass will start putting out more leaves new leaves with better color and and it will recover very well.

Maria: 12:43

Dr Kopp I was telling Taun earlier in the show that the tough part about this is sometimes we see that grass yellowing, we think now we're not giving it enough water, so that's okay. But we have to make sure there's not something else wrong. I mean, my husband found some grubs. He thought it was drought. But it wasn't it was something else. So how do we make sure that we know the difference?

Kelly Kopp: 13:05

Right? Well, it's, that becomes a little bit trickier because things like grubs that you mentioned can mimic the symptoms of drought stress. And so when you're not sure if it's drought stress or some kind of an insect stress or perhaps response to disease, that's when I would always encourage you and I'm sure Taun shares this as well to have a have a chat with your local USU extension office to get some guidance on that. And we also have plant pest diagnostic lab here on our main campus that provides analysis and evaluation of samples from swans(?) like that where it is suspected, maybe it's not drought, maybe it's an insect. So that becomes a little bit trickier to tell the difference. Sometimes with grubs, however, you can do the same thing I just described where you're testing turf dormancy, and that is just dig around a little bit and see if you see grubs actually active in the soil and you would see grub larvae which are if you don't know this, they're c shaped and white in color. And so you may actually see them which would also be an indication that the damage is actually from insects as opposed to drought. But having said that, I would just time of the year with the temperatures we're having, it is more often than not going to be a response to temperature. And the grasses that were growing here especially in northern Utah, the cool season grasses, they prefer cool temperatures it just like it's just like it sounds and so they will come back reliably when things cool off.

Maria: 14:46

Before we get off the topic, Taun and go to watering bushes and trees. We did have a texter who want to know is there a more drought tolerant grass that that people could plant?

Kelly Kopp: 14:57

Oh yes. I'm I'm thrilled to have that. Question because, you know, I think that grasses often get a bad reputation out there, especially in the water community as being very high water use plants. And while it's true that there are some species and varieties that are that are higher water use, we are actually doing a lot of trialing and experimentation here at USU testing very low water use species and varieties. For example, there are some varieties of tall fescue we're working with now that we haven't watered at our research farm this summer. And you would be amazed at how well they have maintained green color. So tall fescue is a species that I like a lot. And within that species, there are varieties that work well here in Utah, and we have done a whole lot of experimentation with those and can make recommendations again, through your USU extension office, you could find out where to locate those.

Taun Beddes: 15:56

One thing I've been concerned about is people are doing in a lot of incidences great jobs on conserving water, but we have a tendency to have trees and shrubs planted in our turf areas. And so the last time we had a drought cycle, we saw that in the aftermath, lots of trees, especially spruce, but many others that were very unhealthy and were infested because of the drought. And so what are your recommendations? I know it's to keep the trees out of lawn areas. But if they're planted there, what are your recommendations to keep those trees healthy and the shrubs?

Kelly Kopp: 16:30

Well, that is an excellent question. And we've talked a lot this this year about prioritizing irrigation. And so you mentioned trees, which I would put at the absolute top of the list in terms of priority. So trees, then shrubs, followed by perennials, annuals and lastly, turf. But as you say, we often have turf in our lawn areas. And so while people are doing a wonderful job conserving water with lawn irrigation, you do have to keep in mind that if you are irrigating trees in the same zone as your turf grass, they're going to require a little bit of extra irrigation to make it through this this growing season. And so, you know, it's somewhat dependent on the age of the tree. But if it's a young tree, adding five or 10 gallons of additional water during the week would be sufficient to keep it going through this growing season. But if it's a larger tree, it's going to need a bit more than that. So for those smaller trees that are in turf areas that are already getting what the state is recommending, which is to irrigations per week of about half an inch, those should be okay. But you can do an extra deep watering, like I said weekly, or perhaps twice monthly, just for a little bit more peace of mind a little bit more supportive, those trees, larger trees, you might be able to do your additional irrigation less than that maybe once every two weeks or once each month, but it would need to be a much deeper watering. So when I say deeper, I mean making sure that the water you apply around that tree drip zone is getting down to about 12 inches, ideally 18, or even a little bit more when you're applying that extra deep watering. So it's really about giving those trees just a little bit extra, keeping that lawn irrigated, as is recommended currently a couple of times a week and that's going to keep things going. But as you say, never hurts to keep an eye on things. And if you start seeing symptoms of drought, stress and wilting in your trees to give it another supplemental deep. And I want to emphasize toward deep watering. Well, the shrubs are there going to be sort of along the lines of a small tree. So most of them are going to get adequate water with what we're doing with our lawn irrigation. But again, if you are seeing symptoms of drought in extra watering, hopefully by hand, you don't need to turn on the entire irrigation system. But a little bit extra every couple of weeks will go a long way towards keeping things going until our conditions get cooler.

Maria: 19:09

All right, anything else important that we need to mention before we let you go?

Kelly Kopp: 19:13

Yeah, one thing I want to be sure I mentioned is and I've had occasion to talk with a lot of citizens recently as I've been traveling around the state, but mowing higher right now or even waiting to mow your grass right now is another way to support it through these high temperatures because higher mowing heights equal deeper roots and that's where we want to be so you know, give yourself a little less work on the weekend. Let that gross grass grow a little bit taller and that will also help.

Taun Beddes: 19:44

I would like to thank you for listening to the homegrown horticulture podcast, I want to give a special shout out to Savannah Peterson for helping with this episode and composing the show music. I also want to give Maria a shout out for allowing us to Use a kiss on greenhouse interview, and Dr. Kelly Kopp, who works with the Center for water efficient landscaping at USU and does a lot with turf grass and water efficiency.

Thank you again for listening.

The homegrown horticulture Podcast is a production of Utah State University Extension.

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