Thrips damage?

[OrchidAddict]

Hey all...

I noticed over the summer that there are small, black, winged bugs nesting down in my orchid media. They fly out when I water the orchids. I had thought them to be harmless initially, but now I see they are actually doing damage. My phal bastiannii seems to be a favorite of theirs as of late. Here's a pic of what they've done to one of the bastiannii leaves:



They must have been working on this one for a while to make such a big dent in the leaf. Here's another pic of some smaller damage on the same plant. I think it's sort of comical that they left this one deformed, but symmetrical.



Anyway, I think they might be thrips, but it's next to impossible for me to get a picture of one, so I'm mostly guessing here. The best way to describe them is that they look like gnats with slightly longer bodies. They are black with clear (I think) wings.

I purchased some organic Neem Oil to treat them with, since I heard it's non-toxic to people, and I have two little kids, so I don't want to be spraying pesticides all over the house (all of my orchids are indoors for the winter now).

Does anyone know how exactly I should use the Neem Oil? The bottle said that I should mix a teaspoon of oil with a half a teaspoon of dish soap and a gallon of water. But then what do I do with it? Do I spray it on the leaves? Do I wet a paper towel with it and wipe down the leaves? Do I water the plant with the Neem Oil mixture?

It would seem like it wouldn't touch the bugs down in the media unless I actually filled the pot with it, but I don't know if that would hurt the plant at all. I'd appreciate any guidance you folks could give me.

Thanks!

[angela]

Hi Jenn
That damage is not Thrip damage. Seems to be,IMO, some sort of chewing bug. Slug,snail, cockroach, grasshopper, if you have any of those around. Can't say for sure what the Black flying insects that you see might be, I would guess they are fungus Gnats. Thrips are so very Tiny you would have to really look very very carefully to see them.
Let' see what others have to say.

[stateless]

I agree with Angela , not thrips. Neem can be sprayed or wiped, you may be able to water the plant with it, not quite sure. I have never used it, because I heard it can burn the leaves if exposed to sun, I grow outdoors and would not be possible to move everything out of the sun until the spray wears off , I'm only going by researching it on line and reading alot of comments, it seems to be a product people love or hate. good luck

[Anteater]

I think I know what bug you are talking about. Check your potting media, especially ones that stay damp, for a tiny white larval stage of this bug. You can move a layer of the top, and they should be underneath if it is damp. If they are present, and this is the same insect I have dealt with, then I agree with the others about the leaf damage not being related to the insect. It looks like you may have a rabbit.....

As far as removing the insect from your collection....well, good luck. I introduced this insect into my collection with a premixed potting concoction that I purchased online. It spread to the rest of my collection. I have had it for a few years now. I don't think they do any damage to the orchids. I think they eat the decaying bark, and they prefer extremely damp habitat. I have knocked the population back, but have never been able to eradicate them. I have just learned to live with them. I have used Organicide and another Neem oil type solution, but they haven't been extremely effective. They help, but not enough.

The best thing that has knocked the population down has been when I go through and repot my collection. After cleaning up the root system, I soak the roots/bottom of the plant in an ammonia/water mixture for 15-20 minutes. The bugs can't take it, but the plants don't care. This drastically wipes out the population, but not completely. I suppose if I repotted every six months, I could wipe them out in a year and a half, but that is just conjecture, since I won't do that.

You could also water the plant with an ammonia/water solution, but it will be less effective due to the solution not reaching every possible spot.

Good luck! I hope you find what is eating your leaves.

[OrchidAddict]

I think I know what bug you are talking about. Check your potting media, especially ones that stay damp, for a tiny white larval stage of this bug. You can move a layer of the top, and they should be underneath if it is damp. If they are present, and this is the same insect I have dealt with, then I agree with the others about the leaf damage not being related to the insect. It looks like you may have a rabbit.....

As far as removing the insect from your collection....well, good luck. I introduced this insect into my collection with a premixed potting concoction that I purchased online. It spread to the rest of my collection. I have had it for a few years now. I don't think they do any damage to the orchids. I think they eat the decaying bark, and they prefer extremely damp habitat. I have knocked the population back, but have never been able to eradicate them. I have just learned to live with them. I have used Organicide and another Neem oil type solution, but they haven't been extremely effective. They help, but not enough.

Hmmmm...well, it's definitely NOT a rabbit, unless there's one hiding out in my closet...hehee! As all of these are indoor plants, I'm just baffled at what is eating them if it's not these little buggers. I did push away some of the bark, but it was hard to tell if it had larvae in it or if there was some residue from the calcium I've used. It didn't look particularly like larvae.

Anyway, I am pretty sure it IS these guys that are munching my plants, although they seem to go for some plants and completely ignore others. I currently have some living in my Paph micranthum pot in my basement, where it's quite cool and damp, and they haven't touched the micranthum leaves at all. However, I have an angel trumpet tree only a few feet away that's getting attacked terribly. So I think they're hiding in the bark during the day and then flying over to eat the leaves of the trumpet tree at night! Nasty little buggers!!

Perhaps I should treat my trumpet tree with systemic pesticide, then leave it out as "bait." These little guys seem to love eating it.

I'm extremely frustrated. I will see if I can get a pic of one of these things. If I stir up the micranthum bark, occasionally one will come buzzing out. They also like to land on my Nook when I'm up reading at night and the lights are out. They like the glow! Of course, that just rubs salt in the wound to see these things strutting brazenly about on my Nook like it's a flashing dance floor!

Anyway, I have yet to try the Neem. For some reason I'm worried it might damage my plants if the sun hits the leaves... I would really like to get a bit more info on how to use it safely.

Thanks for the input! Anyone else have any thoughts?

[TirSigel]

Since you haven't seen them i'd guess slug or snail. I've been getting real small snails which I can only assume are coming in with the rain water. Start keeping an eye on them at night with a flashlight. Maybe the offender will show up...
With the Neem Oil - 2 tsp per 1qt of warm water and a few drops of non-antimicrobial dish soap. spray in the morning before the sun comes up and allow to dry before the sun hits. It's the magnification of the sunlight through the oil drops (like a magnifying glass) which burns the leaves. Plain water can have the same effect it the droplet sits too long, which is why orchids like "dappled" light...

[Teena]

They could be fungus gnats that are flying around. You could possibly have two problems, fungus gnats and something else that is eating your leaves. I have fungus gnats that took up residence in my meyer lemon tree this summer. Since the lemon tree is now next to a plant stand full of orchids I have cross infection. I bought a small container of Mosquito Bits online and have spinkled them on the top of the medium of the orchids and the top of the soil of the lemon tree. Every time I water these plants the fungus gnat larvae are killed. After three weeks I've not seen any flying bugs. Mosquito Bits is a biological mosquito control pesticide, I doubt your kids will try to pick it off the top of the plants. You could add it to a gallon of water and let it soak and then water your orchids with it if you made some sort of sieve like device to cover the opening in the water can so the little bits (they don't dissolve) don't come out of the watering can. Perhaps use a piece of nylon stocking over the opening the watering can.

martha

[coeruleo]

the fungus gnats are annoying, but i have never had real damage from them. here in cailfornia they are very common in house plants because it is so dry, they find a nice damp plant and lay eggs. the grubs can supposedly hurt roots of plants, but i've never had a problem, just annoying gnats flying around. getting rid of them is easy in winter, allow the medium to dry completely. end of gnats. i have had some plants they seem to like more than others. repotting can also get rid of them, until next year. as for neem oil, i just recently began using it. it can burn some types of orchid cacti, but i use it at night, or take the sprayed plant inside out of the sun for a while. it can leave an oily layer on the plants to keep sucking/biting insects starving to death, like aphids, mealies, and mites. it is pretty effective. just don't use it in the sun.

[stateless]

A lot of good info here, if you use the neem let me know how it works, if you want to use a systemic in the angel trumpet tree, love those but they were outlawed in my town because people ate the flowers and died, i digress Bayer 3 in 1 is a good systemic, got rid of white fly.

[Chris1140]

Since you haven't seen them i'd guess slug or snail. I've been getting real small snails which I can only assume are coming in with the rain water. Start keeping an eye on them at night with a flashlight. Maybe the offender will show up....

I agree, may be slugs or snails causing the damage.