Summer Pests Bugging Your Trees & Plants

Ryan Kasak, sales arborist at Davey's Wickes/arborists, a Davey company, office, talks about a variety of summertime pests, as well as how homeowners can spot and get rid of them. 

In this episode we cover: 

• Bagworms (00:48)
• Aphids (3:33)
• Crape myrtle trees in Rockland County, NY (5:24)
• Japanese beetles (6:06)
• Is a healthy tree not as prone to pests? (7:12)
• How do pests act when it's hot and dry? (8:13)
• Spider mites (8:46)
• Spotted lanternfly (11:07)
• How did Ryan become a sales arborist? (13:06)
• What can homeowners do to get rid of pests? (13:36)
• Lace bugs (14:53)
• Treatment application for large plants (15:57)
• How do arborists stay informed about pests and disease? (16:28)

To find your local Davey office, check out our find a local office page to search by zip code.

To read our insect and disease blogs to stay informed on the different pests that pose a threat to your landscape and garden, click here - Insect & Disease Issues Blogs.

Connect with Davey Tree on social media:
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LinkedIn: The Davey Tree Expert Company 

Connect with Doug Oster at www.dougoster.com. 

Have topics you'd like us to cover on the podcast? Email us at podcasts@davey.com. We want to hear from you!

Transcript

Doug Oster: Welcome to the Davey Tree Expert Company's podcast, Talking Trees. I'm your host, Doug Oster. Each week, our expert arborists share advice on seasonal tree care, how to make your trees thrive, arborists' favorite trees, and much, much more. Tune in every Thursday to learn more because here at the Talking Trees podcast, we know trees are the answer.

This week, I'm joined by Ryan Kasak. He's a sales arborist for Wickes/arborists, which is a Davey company based in Rockland, New York. Where is that, Ryan?

Ryan Kasak: Rockland County is southern part of New York, just north of the city, west of Westchester, right on the other side of the river.

Doug: Today, we're talking about summer pests. What is the first one that comes to mind for the summer? I'm saying aphids. What is it for you?

Ryan: I would have said aphids as well. Right now, I would have said bagworms just because it was fresh, and I saw it right before I hopped onto this call here.

Doug: Start with bagworms then. Tell us what it looks like, and what they do, and what trees they bother, and what you can do about it.

Ryan: Sure. Bagworms really prefer going after evergreens. You're not going to find them on deciduous trees, arborvitaes, junipers, cypress. What they'll do is they'll form little sacs or what it looks like little cocoons on the trees, and then when they are in the larva stage is when they'll actually cause damage. They could wipe trees out very quickly. Within a week or two, you can see some pretty devastating damage to the trees, and rarely are they going to recover.

Doug: Is it defoliation? Is that what they do? They eat the leaves?

Ryan: They eat the leaves, yes. They'll use the tree. They'll use debris and leaves to make that little sac. Then when they emerge from that, they'll start feeding right away. Like I said, it's significant damage that you'll see.

Doug: The sac is pretty identifiable, right?

Ryan: In the beginning, it's hard to see sometimes when there's not a whole lot of them just because it's green and blends in fairly well with the tree. After a short time, they'll start to turn brown. Once you know what to look for, they stand right out.

Doug: What do we do? Can we just cut them off or do we have to do something else?

Ryan: Depending on how bad the infestation is. If it's light, you can pick them off one by one. A foiler application is a fairly easy, reasonable treatment to take care of them. They have organic options that we could use. Foiler application is usually the first recommendation. Especially around here, we're seeing a lot of these arborvitaes and that type of plant species planted for privacy, so there's a lot of them. It's rare to find just one or two on a property.

Even if you have a whole hedge to go in and pick them out one by one, even if it's not a significant infestation, is going to require some time.

Doug: If they do hatch out, then what?

Ryan: If they do hatch, that's when they're going to start the feeding damage. That you will notice almost immediately with the rate that they munch and feed.

Doug: What can you guys do once they hatch?

Ryan: Once they hatch is when we're most likely going to time the treatment. Once they're hatched and they're actively feeding is when we get the best results with treatment.

Doug: Let's talk aphids. Whenever I see an aphid infestation, I'm thinking that the plant isn't getting everything it needs. Maybe that's not true. Explain a little bit what those aphids look like when they're really going at it.

Ryan: Sure. Aphids, there's several different kinds of aphids. They come in different colors. There's plant species that they prefer to feed on. In general, they are piercing sucking pests. They have a needle-like mouthpiece that they'll actually be sucking on the sap of the leaf. They will cause a stippling type of damage. While they're feeding, their excrement is a clear sticky substance that a sooty mold will start to grow on. Not only for the plant, but if it's the trees over the patio or over the pool, they become quite a nuisance as well just because of that residue that they leave.

That residue is also going to attract other insects, pests, bees, ants, things of that nature, which it's not something desirable to deal with most of the time.

Doug: You don't want honeydew and sooty mold all over your deck, or pool, or outdoor dining table, right?

Ryan: Exactly.

Doug: [laughs] Are there certain trees that aphids prefer?

Ryan: Yes, there is. We see them feed on all different species, but crape myrtles, river birch, lindens. There's a handful of trees that they do prefer to go after. It always seems more of those ornamental, and those higher value trees that are closer to the Hollywood areas along the walkway and patios is where they tend to go after, it seems.

Doug: In your area, do you have good luck growing crape myrtles? That's a borderline plant here in Pittsburgh.

Ryan: We're in the same situation where it's borderline in Rockland County. It really prefers to be a little south, but we see them going in some landscapes. If it's a mild winter, they do well. If it's a little bit harsher of a typical New York winter, they don't always come out as well as they went in.

Doug: When they do work, though, and you do have a mild winter, that's a pretty amazing-looking bloom when the tree does its thing, don't you think?

Ryan: Oh, they're beautiful. You drive down into Maryland and Virginia in the right time of year, and they're gorgeous.

Doug: What else is on your list of things were you thinking when you said summer pests?

Ryan: Another one I always need to bring up is Japanese beetles. Japanese beetles we know are also grubs, so they're a problem for turf as well as for our ornamental plantings. Rose bushes, cherry trees, some of the most common plant material that we're going to see them going after. They're easy to see. They have that emerald green color. I think almost everybody could identify them, even if you're not spending a lot of time outside.

Doug: On a big tree, what do you do about Japanese beetles? I know on a smaller one, there's lots of different ways to deal with them. On a big tree, how do you get to them?

Ryan: Depending on the size of the tree, if we had to treat a systemic injection, it would probably be the best treatment option. To do a soil drench or a soil injection, something that allows the tree to absorb that product and distribute it throughout the canopy to get control would probably be the best option.

Doug: Let me ask you something. We talk to arborists all the time who talk about having a healthy tree. Is a healthy tree going to be less prone to pests, or will it fight off the pests better, or the pests are just there and it doesn't matter?

Ryan: I agree with that beginning statement that healthy trees definitely defend themselves a little better. Certain pests, especially something, a pest like an aphid, is going to go after those stressed trees first. A tree that's in the right planting conditions, in the right location, that's being pruned regularly and fertilized, and just overall in a better environment, is definitely going to be more tolerant to many of the pests we're seeing out there.

Doug: When I said aphids attack things, I always wonder if that plant isn't getting what it needs. I was right. That's what you're saying.

Ryan: That is what I'm saying.

Doug: What kind of season has it been for you in New York?

Ryan: Very wet in the spring this year. We generally had a wet spring, and then it seemed like someone almost turned off the faucet and the rain stopped for a while. Recently, it's been hot and dry.

Doug: What does that mean for pests? Is hot and dry a good thing or a bad thing for pests?

Ryan: The pests usually do well when it's hot and dry. Going in line with what we just said, a lot of plant material is a little more stressed out, so the pests do well. Spider mites, when it's hot and dry in the summer, that's another pest that seems to do well.

Doug: Let's talk about them then. Is there one plant like a dwarf Alberta spruce that spider mites really like? Is that right? Or are there other plants that they really go after?

Ryan: Yes, definitely. There's different kinds of mites. Some of them feed in the cooler season, spring and fall. Some of them feed in the summer. The two-spotted mite is probably one of the biggest mites that we see in the summer. You're spot on. Alberta spruce, a lot of spruce in general, actually, they'll feed on.

It's usually, even for homeowners, a pretty easy way to go and tell if you have mites is to do the paper test. Not sure if you heard of that. Basically, going up to the plant, make sure it's dry, otherwise, your paper gets all wet. Basically, putting a clean white sheet of paper on your clipboard underneath, giving it a shake, and then doing this mirror test, just slapping your clipboard and running your hand across it. You'll be able to see the mites and determine if there's a population there or not.

Doug: You basically know that spruce in general, they're probably going to have mites of some type. Do you see damage first? If you went out to a place and you saw a bunch of spruces, would you just do the paper test and see what was going on there?

Ryan: More than likely, I would just take a look with the hand lens or do a paper test just to confirm if we're seeing any activity or not. Then there's always the conversation with the threshold. The plant has a threshold if it could sustain and do okay with the pest population, and the client also has their own threshold that determines if treatment is warranted or not.

Doug: Well, that's interesting that you bring that up, because that threshold, certainly for the homeowner, makes all the difference. At my garden, I'm like, "As long as they're not messing up the ornamental plants or stopping the vegetables from doing their thing, the bugs are fine." Not everybody feels that way, do they?

Ryan: Absolutely. Some people do not want to see any type of bug activity at all on the property. [chuckles] Like I said, the threshold between the plant and the homeowner could be very different.

Doug: What else is on your list? Anything else in the summer that you can think of that has been a problem? Oh, I know. One thing I did want to talk to you about, have you seen the spotted lanternfly yet? Down here, we had it bad for a couple of years, but now it's there, but it's not as bad as we thought it was going to be.

Ryan: Sure. We've seen the spotted lanternfly, absolutely, starting a few years ago. I think initially, we thought it was going to be much worse than what we ended up seeing around here. I know down in Jersey and even in your state over in Philly, it was a lot worse, and we were expecting that same follow-up. We didn't end up seeing it as bad, I believe. Obviously, the Atlantis trees, there are certain species that we do see them on more frequently.

Generally, I think we got lucky so far. We're obviously still seeing activity. It seems to be more sporadic. You saw pictures and videos in the beginning where you couldn't even see the trunk of the tree because there were so many of them feeding. Rarely did we see that over here in Rockland County.

Doug: Just like you used the paper test for the mites, I've got a above-ground pool that's right underneath a tree of heaven. My paper test is the pool filter. I see lots of nymphs in there, and that tells me they're back again.

Ryan: They are. [chuckles]

Doug: Interesting enough that again, everybody thought this was going to be such a terrible infestation. The worst thing about them is what they do is just like the aphids, is that honeydew. They like maples. Boy, if you have a maple over your deck, and you've got lanternfly, it's just like having an infestation of aphids. It's no fun for anybody.

Ryan: For a while there, we were calling them picnic ruiners because it made you not want to be outside when they were really active in the summertime.

Doug: Ryan, how did you find your way to this job? Why is it right for you?

Ryan: I've always loved being outside. I always knew I couldn't be stuck behind a desk. I went to school for biology. When I graduated, I had to make a decision about what I wanted to do. I started as a plant healthcare technician. From there, I just continued to learn and grow in the industry, and worked my way into becoming a sales arborist.

Doug: For a homeowner, is there a certain thing they should be looking for in the summer when thinking about pests? Should they be looking around? We know we want our arborist to be on the property at least once a year, but is there something that the homeowner can do to be an advance scout?

Ryan: I would say if a homeowner sees any type of pest activity, whether it's lace bugs, Japanese beetles, either they see the actual insect themselves, or if they see a difference in the plant whether it's Japanese beetle damage, and you notice skeletonizing damage on the leaves, or if you see a honeydew from aphids feeding, definitely the homeowner could be vigilant and give us a call, give their local arborist a call if they do see something. That way, it will allow us to react a little quicker.

Doug: Just knowing what that honeydew is is important because a lot of times people think it's something like a sap dripping from the trees. They'll say, "I can't stand having that tree there because it's dripping sap," when all in actuality, it's just aphids dropping honeydew.

The other thing I did want to talk to you about though were lace bugs because, boy, they can be a problem. I've got them in my property on rhododendrons and Japanese pieris, which are two pretty hardy plants, but if they get infestation with lace bugs, it can take them down pretty quick. What plants do they affect, and what does it look like if there's lace bug infestation?

Ryan: Sure. We'll most commonly see lace bugs on andromedas and azaleas in southern New York here. They'll actually, most of the time, be on the underside of the leaf. It's important to turn that leaf over, take a good look. You'll see that stickling damage. It almost looks like a bunch of lighter-colored spots on the underside of those leaves. It's important when the tech is coming out to do a treatment for them, that they are spraying and treating the underside of the leaf as well. Sometimes just a topical application isn't going to get good treatment.

Doug: Again, when you've got a big plant, how do you get the application up there?

Ryan: Luckily, like I said, we have systemic options as well. With the trucks that we have, we can spray 60-plus feet comfortably. In my experience, I've never treated a tree that size for lace bugs, which is good. If we can't reach it with a fuller application, we always have systemic and injectables as options.

Doug: There's always something new coming, Mother Nature is sending our way. It spotted lanternfly now. Of course, emerald ash borer was devastating. Talk a little bit about how you have to stay informed, and about what the next thing is. Whether it's going eastbound or westbound, something's coming your way.

Ryan: Sure. Winter always seems to be a little bit of a downtime for us. That's when we catch up on our conferences and most of our updates from Davey, from the states, from the industry as a whole. We'll get a lot of our updates. Another one right now is beech leaf disease that's been newer where there's a lot of research going on. Box tree moth is another one that we don't see yet in our backyard, but it appears that we're slowly being closed in on. We're keeping our eyes open for the box tree moth as well.

It's mostly just staying up-to-date, winter conferences, and then, weekly bulletin boards from different universities and the Cornell Extension all have resources that'll let you know what's going on around you, and lets you be more vigilant on those topics.

Doug: All right, Ryan. Thanks very much. Appreciated our talk. You schooled me on a lot of problems that are in our area, too, and on most of the eastern part of the US. Appreciate your time and information. I'm sure we'll talk again soon. Thanks so much.

Ryan: Doug, really appreciate it. Thanks for having me on.

Doug: All right, you tree lovers. Tune in every Thursday to the Talking Trees podcast from the Davey Tree Expert Company. I'm your host, Doug Oster. I need you to do me a favor as always. I want you to subscribe to this podcast so you'll never miss the show. What should we be covering? Let us know. There's two ways to reach us. First is email. Send it to podcasts@davey.com. That's P-O-D-C-A-S-T-S @ D-A-V-E-Y.com. You can also click the link at the end of our show notes to text us a fan mail message. I promise you, your ideas might be on a future podcast. We would love to hear from you.

As always, we'd like to remind you on the Talking Trees podcast, trees are the answer.

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