Tiny clear worm or larvae

[SaraJean]

I found a couple of these on my Den laevifolium this morning. They had eaten off all three of the new growths and were inside whatever hole they had created. I’m not sure what kind of larvae this is or how to treat. All I have in my house right now is some Sevin and hydrogen peroxide.
With trying to stay home as much as possible, do you think either of those would work?


This is a picture of one of the little jerks (I had been babying this Den for the past year, and this was its first sign of improvement. Now I’m back to square one). The worm is on the head of a q-tip taken with a macro lens, so it’s tiny

[Ray]

I can't identify it, but be aware that most pesticides do not kill eggs or larvae., and the two I'm aware of that do - azadirachtin and BT - take time to work.

Hopefully, someone with better knowledge can chime in.

[SaraJean]

Originally Posted by Ray

I can't identify it, but be aware that most pesticides do not kill eggs or larvae., and the two I'm aware of that do - azadirachtin and BT - take time to work.

Hopefully, someone with better knowledge can chime in.

BT.. is that the stuff in mosquito dunks? My local hardware store should have those (and they are doing contactless delivery to the neighborhood) so that might be an option

[Ray]

Yep. That's it.

[SouthPark]

SaraJean ----- Is the plant growing in a regular potting media? And if it is, then is the media wet for all (or most) of the time?

[Leafmite]

Sevin usually kills everything but for spidermite. Good luck!

[SaraJean]

Originally Posted by SouthPark

SaraJean ----- Is the plant growing in a regular potting media? And if it is, then is the media wet for all (or most) of the time?

It’s in medium Orchiata with a tiny bit of live moss over the top. It’s a Den. laevifolium so it is somewhat damp at all times, with frequent waterings, not soggy or anything. It was just repotted about 2 months ago (and unpotted it today) so the media is still good with a nice root system. I had looked up ‘clear black head larvae’ and came up with fungus gnat larvae but I didn’t think those would destroy a an orchid like that, so I’m not sure if that’s correct. The growths were eaten clean off and they had burrowed a hole inside where the growths met the old pseudobulbs

---------- Post added at 12:15 AM ---------- Previous post was at 12:13 AM ----------

Originally Posted by Leafmite

Sevin usually kills everything but for spidermite. Good luck!

I’ll give it a whirl since I have that on hand before the dunks come in, thanks

[SouthPark]

Originally Posted by SaraJean

I had looked up ‘clear black head larvae’ and came up with fungus gnat larvae but I didn’t think those would destroy a an orchid like that, so I’m not sure if that’s correct.

Thanks for your response SaraJean! I purchased some mosquito dunks from USA too (haven't used yet), but saw the members here talking about it's usefulness against things like this.

I only just asked about the state of the media, as --- in some cases --- some media dry-out can keep some of these critters at bay. Maybe the mosquito dunks will keep these things under control!!

[aliceinwl]

It looks like the larva of some type of fungus gnat, probably one of the larger species. Not sure if that is of any help

[Dollythehun]

I've had good results sending pictures to our state's ag Dept. They're very prompt. I'm betting it's something other than fungus gnats.