I'm seeing holes in all of the leaves on what I think is an Elm tree, as well as the nearby younger trees of the same sort. It looks like bug is eating away at the foliage, but I can't see them.



Any ideas on what this is, and how to treat? Any & all advice and/or input is welcome. Thanks! Cotton

What's on the under side of the leaves?

At first I didn't see anything, but now that I've taken a closer look, I can see these little creepers on there:



...so not cool.

EDIT: A web search makes me think it might be Elm Beetle, but sadly search engines have become useless to the point of not saying how to treat them. All these, "What is <insert subject>?" & "Characteristics of <insert subject>!" websites are incredibly unhelpful. <end rant>

I think your options are all chemical. Here's some info

https://ipm.ucanr.edu/PMG/PEST...

https://extension.colostate.ed...

Many thanks @NMoasis ! According to:

https://extension.colostate.ed...

"Soil applied systemic insecticides

Imidacloprid (Bayer Advanced Tree & Shrub Protect & Feed Concentrate II, Bonide Annual Tree & Shrub Control, ferti-lome Tree & Shrub Systemic Insect Drench; Ortho Bug B Gon Year-Long Tree & Shrub Insect Control, Merit, Mallet, Zenith, Criterion, others)
Chlothianidin (Bayer Advanced Tree & Shrub Protect & Feed Concentrate II, Arena)

Insecticides applied as sprays to leaves

Azadirachtin (Azatin, AzaGuard, Azasol, BioNeem, others)
Bifenthrin (Talstar, Onyx, Ortho Bug B Gon Insect Killer for Lawns & Gardens)
Carbaryl (Sevin, Carbaryl)
Cyfluthrin (Tempo, Bayer Advanced Vegetable & Garden Insect Spray)
Cyhalothrin (Scimitar, Spectracide Triazicide Insect Killer for Lawns & Landscapes, Cutter Backyard Bug Control Spray Concentrate
Permethrin (Astro, Permethrin, Hi-Yield Turf, Termite and Ornamental 38 Plus, Bonide Eight Insect Control Yard & Garden, others)
Spinosad (Conserve, Bonide Captain Jack's Dead Bug Brew, Natural Guard Spinosad Landscape & Garden Insecticide, ferti-lome Borer, Bagworm, Leafminer & Tent Caterpillar Spray)"

Very helpful info there. I'm going to learn how to make my trees beautiful with this info. Much appreciated! Cotton

Good luck Cotton. I wouldn't be happy using most of those products. If this is a new, recent infestation, you might consider waiting till next season and see how it looks. Insect population outbreaks are often transient.

I bought the house with two already-dead trees in the back yard, so I doubt this is a new problem. It looks like Bayer makes both a leaf treatment as well as a soil treatment in consumer-grade, and there's one Elm with a very large bare spot where the bark has come off (possibly a very old wound) that I'm going to put roofing tar over to try and protect it. I would be much more hesitant about using strong chemicals on veggies, but I figure as long as I'm not polluting anything beyond my own yard, then no harm = no foul. Cotton

I would never use a systemic because they aren't specific about what they kill. Anything that eats the dying beetles will be poisoned also. When the trees bloom, you will be killing bees and other pollinators. Sorry but you are poisoning beyond your yard.

Lucy68 said: I would never use a systemic because they aren't specific about what they kill. Anything that eats the dying beetles will be poisoned also. When the trees bloom, you will be killing bees and other pollinators. Sorry but you are poisoning beyond your yard.

I tend to shy away from poisons if I can help it. There are specific cases that necessitate extreme measures (ie: whatever those giant red ants are that keep making bald-spots in [what's supposed to be] my yard.) So, what product would you recommend? ...and you can't say "electric chainsaw". Seriously, I welcome and appreciate any & all input in my threads, so lemme know what'cher thinkin'. Thanks, Cotton

EDIT: I quit trying to poison the harvester ants because they are a staple food-source for horny toads.

Personally, I probably wouldn't do anything but I've never had to deal with elm beetles. Friends who have complain more about beetles coming in for the winter than eating their tree.

My go-to is always the University of California's Agricultural Resources Program. Elm Beetle control sounds a little more complicated than I thought it would be...

https://ipm.ucanr.edu/PMG/PEST...

Yeah, I kinda' breezed through that one, like:

MANAGEMENT

[Blah, blah, blah,] ...manage it with an integrated program that incorporates good cultural practices, conservation of natural enemies, regular monitoring, and the use of less-persistent insecticides, bark banding, or systemic insecticide.

[Okay, that's the plan.]


Cultural Control

[Yada, yada, yada,] ...protect trunks and roots from injury.

Check for dead or dying branches and promptly remove them.

Avoid unnecessary pruning.

[Nothing new there.]


Biological Control

Predators of the elm leaf beetle include certain bugs, earwigs, lacewing larvae, and predaceous ground beetles.

Conserve these parasites and predators by avoiding foliar applications of residual (long-lasting), broad-spectrum insecticides.

[Obviously there's not a significant population of these to begin with.]


Chemical Control

[Okay, done reading.]

It took 10,000 words to say so, but there's not a whole lot of options. I usually can't afford the fancy organic stuff anyway, but it'd be nice to have something available.

Sorry I bored you.

@CottonTexas The elm beetle is a big issue here for my weeping elms. I have 3 and I use a grannual systemic in winter for one that always seems to attract the beetles. This prevents the larvae of the beetle from overwintering in the soil. The larvae and beetles can be a nightmare for my garden . Another type of larvae called the gypsy moth which can defoliate an entire tree in a couple of years also is treated.

There are 3 weeping elms and are planted near the patios. The beetles also bite worse than mosquitoes and there are thousands of them flying around all summer if not treated. After systemic treatment the robins still nest in the trees in spring. Various beetles have infested many of the trees in my tree collection. I don't like seeing the trees infested with insects .The damage they do is irreversible.

In my experience I have no choice but to treat many trees thruout the garden every fall once the leaves have fallen and the rains have began.
It's so much more peaceful in the garden without the beetles . Otherwise by summer the leaves from the elms would fall prematurely and actually resemble a premature loss of leaves leaving bare open spaces in the tree canopy. And constantly raking the leaves up to prevent the beetles from spreading to the other trees .

It's a personal choice to use a systemic to treat a few trees that are susceptible to insect infestations. Or watch a slow death occur over time accumulating an increasingly larger infestation yearly. Or remove the trees and plant another type of tree that is not an issue with insects . Or contact your nearest extension service in your area for more information.

PS: A bit of my background - I have been gardening for 30 years and my garden is 2 and 1/2 acres. Planted over 250 trees and shrubs . Gardening is always something beautiful, aways something unique and always full of beneficial insects and harmful insects.

Lucy68 said: Sorry I bored you.

Actually, NMoasis posted that link before you did. Sorry to sound ungrateful, I just meant to do an overall breakdown of the lengthy article.

@bumplbea That sounds like a good plan that I'll be able to follow once I get these things under control. I'd much prefer not having to dispense chems any more than I have to.

CottonTexas said: Actually, NMoasis posted that link before you did. Sorry to sound ungrateful, I just meant to do an overall breakdown of the lengthy article.

NMoasis posted an article from Colorado State and was the cliff notes for the one I posted from U. of California which went into a lot more detail I would appreciate knowing if I was dealing with elm beetles but then I'm a garden nerd.

It's the first link in the post:

https://garden.org/thread/view...

I can see that it was overlooked, and I always appreciate input from all perspectives. I didn't mean to sound like I was being rude at all. I'm frequently concerned that my messages are being read as more abrasive than the ideas are in my head. I sincerely apologize if that's the case. Anyhow, I think we both agree that poisons are bad, and we should try to avoid them when & where we can, both for our own sake as well as our neighbor's. Peace, Cotton

No problem. I did overlook NMoasis' first link and it does have excellent information.

No worries, we're all good here.