Pest ID? Have what looks like large 'nibbles' taken out of my leaves, cannot find a pest...

[SU2]

Over the past week I've been finding more and more affected leaves (it's now affecting all 3 separate display benches in my garden), the past 2 days it's seemed to speed-up how widespread it's become.. Here's a prime-example of a badly-affected tree (it's a bougie, almost all of my specimen are bougies!)

It's not aphids/mites, it's not those little green caterpillars that eat leaves and form cocoons by sticking leaves together- in a week (maybe 8-9 days!) of this happening now, I couldn't find a single trace of the bug(right?) that's doing it, or any residues/cocoons/anything, excepting what's in that ^ picture where you can see the hole in the leaf is half translucent, that seems to be a tell-tale sign although the underside of the leafs never show anything the top doesn't.

I *may* have found something useful today, although I worry it may be an unrelated mealy-bug affected leaf (this infestation of nibbled-leaves is definitely not mealy bugs, the following pics of white residue are the first evidence I found in a week, mealy-bugs leave that stuff everywhere!), I found a leaf and turned it over to find some white dust and two white lumps, they were not alive and they wiped-off easily:


Maybe that's ^ my first actual trace of this pest, or maybe it's my first sighting of a mealy-bug issue on a bougie (I've *never* had that before, only my hibiscus & firebush ever had mealy-bugs, and all of the trees-in-question right now are bougies), am unsure and hope you guys can shed some light on this one for me so I can thwart any further damage!!

(I should note that I've had an increasing amount of those 'leaf miner' worms, the ones that leave waxy trails as they eat their way through the center of a leaf, though I suspect that's just a wholly unrelated issue. I'll probably pull ~10 leaf-miner leaves every morning when I go outside, out of ~50 trees)

I've got neem/daconil/bayer's 3-in-1 to treat but don't know what to do as I don't know what it is, unsure if I should be going for just the leave or systemic or what, any suggestions on what to do or ID's on the problem would be greatly appreciated!! Thanks for reading

 

[Bonsai Nut]

Slugs.

Look under your pots.

 

[Pachycaul]

Leaf cutter bees?

 

[Vin]

Slugs.

Look under your pots.

Slugs? I thought all the slugs were over on IBC?

 

[Gustavo Martins]

Yep looks like slug or caterpillar

 

[Mike Corazzi]

I would suspect a VEGAN !!!

 

[milehigh_7]

Slugs? I thought all the slugs were over on IBC?

ROFLOL!!!!

 

[milehigh_7]

I would suspect a VEGAN !!!

They are always committing herbicide and nobody bats an eye...

 

[Pachycaul]

Still going with leafcutter bees. (Genus Megachile) Slugs leave shiny mucous trails, and move slowly enough that sooner or later you're bound to catch them in the act. Caterpillars don't eat and run. They set up housekeeping. Leaf miners plow tiny trails through the underside only, even avoiding vein structures in favor of the tender bits. Grasshoppers do eat and run, but rarely confine their grazing to a neat semi-circle at the edge of leaves. They will devour everything short of lignified twigs. The fact that there are no pests visible reinforces a case for leafcutters. They don't consume leaf tissue, instead they use it for nesting material. They are solitary, and asocial, though several bees may visit a rich bougie forest separately. They are good pollinators, which is why they were introduced. It can't possibly be vegans, they're highly allergic to whatever you've gone out of your way to offer them

 

[Bonsai Nut]

Slug damage on hosta leaves for comparison...

 

[Stan Kengai]

Grasshoppers.

 

[SU2]

Slugs.

Look under your pots.

Great thank you!!! I've yet to have issue with slugs, but about a week / week+1/2 ago I did find a small slug (wasn't on a bench though, all these trees are on benches), have also found a good amount of snails but again not on the benches..

What should I do besides search&destroy? Are there traps I should set or anything? Would using one of my systemics like 3-in-1 or Daconil do anything to dissuade them? For the past couple days I've just been keeping them barely-moist-enough to not wilt too-hard, trying to reduce the appeal of the leaves while I figure this out.. (and just to be clear, all of the affected specimen are on benches, in fact many of them are on a bench that doesn't have a real 'table top' it's just got a metal-wire shelf...will go searching and see if I can find any! How big a slug would you be expecting to find? Surely not the large type!)

 

[SU2]

Yep looks like slug or caterpillar

How would you treat it? I'm about to go searching for slugs under my containers and see what I can find, but it's so wide-spread at this point that I don't know that there's any practical approach besides treating all the specimen, I've got Daconil, bayer's 3-in-1, neem, insecticidal soap...should I use the 3-in-1 so I have a systemic insecticide active in *all* of my 'trees' (bougies)?

 

[SU2]

Still going with leafcutter bees. (Genus Megachile) Slugs leave shiny mucous trails, and move slowly enough that sooner or later you're bound to catch them in the act. Caterpillars don't eat and run. They set up housekeeping.

This resonates with me, I mean I've had caterpillar issues before and for as much leaf as I've had eaten I should've found 50+ caterpillars, sticking my leaves together trying to cocoon, dropping those black dots on the leaves below(eggs?), and that's not the case here (I do 2 visits daily, watering and inspecting, I've got too many specimen not to...an un-discovered aphid or caterpillar issue can explode out of control if not found and eliminated quickly, yet this whole week as I've watched the leaves get more nibbled every day I've yet to find my suspect and trust me I'm looking!!

Leaf miners plow tiny trails through the underside only, even avoiding vein structures in favor of the tender bits.

Yeah I've got them as well, I probably pull 5 leaves every morning and every evening that have that waxy trail!

Grasshoppers do eat and run, but rarely confine their grazing to a neat semi-circle at the edge of leaves. They will devour everything short of lignified twigs. The fact that there are no pests visible reinforces a case for leafcutters. They don't consume leaf tissue, instead they use it for nesting material. They are solitary, and asocial, though several bees may visit a rich bougie forest separately. They are good pollinators, which is why they were introduced.

What do you mean 'they were introduced'? And while I'm about to start googling them to learn more, any quick tidbits you could give that wiki won't would be appreciated!! Specifically what on earth to do to get them to stop! I've got 'attractive' pollinator plants in my nursery (purple porterweed, marigold, passionflower vine etc) and have always had bees (and caterpillars that become monarch butterflies, we foster a lot of monarch development here!) but never had this issue before (I should note this is my first year of bonsai, so my first fall with a collection of trees(shrubs).

It can't possibly be vegans, they're highly allergic to whatever you've gone out of your way to offer them

ROFL!!!!

 

[SU2]

Slug damage on hosta leaves for comparison...

View attachment 168667

See that looks like they stay in 1 spot a lot longer than whatever my pest is, my worst-nibbled leaves don't approach what I'm seeing in that pic (and for that type of work to be done by a slug I'm wondering how I could've possibly missed them when it's been a ~week of looking and haven't found anything (twice daily checks, I probably spend ~10min minimum every visit to the nursery)

Never noticed your signature before, love it ;D

 

[SU2]

Grasshoppers.

I've yet to find a grasshopper in my garden, let alone on the benches :/

 

[SU2]

I know I've asked this before but cannot remember if there's a 'standard' approach for it, but what can/should I do to the wooden-legs of my bonsai benches to prevent insects traversing it from the ground? Would be nice to at least limit it to flying bugs and get rid of a good amount of potential pests, I mean I'm very happy I was convinced (by this board!) to get all my specimen off-ground and on-benches, but I've yet to do anything that'd dissuade bugs from just climbing-up the legs of the benches, really want to do something here! Honestly I'm about to just grab vaseline and put a 1/2" band around the top of each leg so no bug can walk-across!!

 

[GailC]

What about earwigs? I have a problem with them eating my rhododendrons and the damage is similar.

 

[bonsai-ben]

I know I've asked this before but cannot remember if there's a 'standard' approach for it, but what can/should I do to the wooden-legs of my bonsai benches to prevent insects traversing it from the ground? Would be nice to at least limit it to flying bugs and get rid of a good amount of potential pests, I mean I'm very happy I was convinced (by this board!) to get all my specimen off-ground and on-benches, but I've yet to do anything that'd dissuade bugs from just climbing-up the legs of the benches, really want to do something here! Honestly I'm about to just grab vaseline and put a 1/2" band around the top of each leg so no bug can walk-across!!

Nothing. Bugs arent bad. There are good ones, and bad ones, and ones that do nothing. Learn your garden.

 

[Pachycaul]

...
What do you mean 'they were introduced'? And while I'm about to start googling them to learn more, any quick tidbits you could give that wiki won't would be appreciated!! Specifically what on earth to do to get them to stop! I've got 'attractive' pollinator plants in my nursery (purple porterweed, marigold, passionflower vine etc) and have always had bees (and caterpillars that become monarch butterflies, we foster a lot of monarch development here!) but never had this issue before (I should note this is my first year of bonsai, so my first fall with a collection of trees(shrubs).

@SU2- read they are a Mediterranean native introduced to US to assist native honeybee populations to pollinate cash crops. https://buzzaboutbees.net has an excellent article "The Leafcutter Bee" Years ago, I too was puzzled by the same type of damage on leaf edges. I had to basically sit on affected plants before catching the culprits in the act. It looks like there are several species in the genus with similar behavior, in differing sizes. Part of the reason they may be so elusive is that not only do they have to construct nesting chambers, but gather sufficient food (flower parts, pollen,nectar) to place in the chamber before laying an egg and closing up the opening. So, in nesting season, they don't spend much time in any one place (busy as a bee?) Many examples of their work via Google.