Small clear inchworms? - Orchid Board

Royal · #1 11-17-2008, 10:56 AM

Anybody ever have issues with caterpillars or small clear worms? I've found a few of these munching on some seedlings (in sphag). Looked like a snail trail, but some digging uncovered a little worm thing, about 1/4 inch long, clear with a black head. Devastated some seedlings.

I also noticed a little webbing on a 'blasted' bud and investigated. Turns out this thing was just hanging out in there - eating on the unopened flower from the inside out!

Maybe that's why last weeks spraying didn't kill it. I killed it the old fashioned way.

Anybody deal with these nasty beasts? How?

Ross · #2 11-17-2008, 12:12 PM

Sounds like fungus gnat larvae. At least the description is similar. I haven't had them get that agressive, but as soon as I see one, the whole mount (usually it will have sphagnum that is decaying) gets sprayed heavily with Schults Garden Safe Houseplant & Garden Insect Killer. The adults would be like fruit flies if that's what buggin' you

The Schultz stuff is Pyrethrin.

camille1585 · #3 11-17-2008, 01:27 PM

I was tempted to say the same thing as Ross, they might probably Sciaridae (fungus knats) larvae. The description certainly fits... But one thing that bothers me though is that I don't think these larvae actually eat plant or make webbing. I think their primary source of food is decaying plant material or fungal mycelia. I'm trying to think of what else they might be...

Ross · #4 11-17-2008, 02:11 PM

Quote:

Originally Posted by camille1585

I was tempted to say the same thing as Ross, they might probably Sciaridae (fungus knats) larvae. The description certainly fits... But one thing that bothers me though is that I don't think these larvae actually eat plant or make webbing. I think their primary source of food is decaying plant material or fungal mycelia. I'm trying to think of what else they might be...

Webbing is definitely positive. They do that. When the fungus is gone, they turn to other food sources. Nothing definite, but still a good possibility. In any case, I'd spray, if the plants were mine. No sense taking prisoners in this battle!

Royal · #5 11-17-2008, 02:45 PM

Oh, I take NO prisoners - if I can help it. I've sprayed that exact stuff last week. I guess I didn't spray the unopened bud in which I found that little bugger.

I think both of your diagnoses fit. Thanks. I should have never went back to the sphag. I just didn't have anything else for my seedlings.

Becky15349 · #6 11-17-2008, 03:26 PM

Good luck, this sounds awful!!

Ross · #7 11-17-2008, 04:07 PM

Quote:

Originally Posted by RoyalOrchids

I should have never went back to the sphag. I just didn't have anything else for my seedlings.

Don't blame the sphag - it had nothing to do with the situation. If you have adults, soon you will have worms (babies) and webs. If you see webs, suspect fungus gnats. Plain and simple. Spray the culprit and the worms will go away. In the meantime, keep some of those yellow sticky traps around the plants to catch the adults. These guys are real suckers for yellow and every night the population will increase on the traps and decrease amongst the orchids. Just a hint.

Royal · #8 11-17-2008, 04:34 PM

I don't blame the sphag, I know it's all on me. I just know that I don't do well with it. Most of my plants are in bark or on bark, so anything is sphag usually stays too wet for too long. I also should have known better about preventative spraying. I get smart for a while, then I get a little complacent when no bugs come around. Then another tragedy sets me on another bug killing spree, until I get lazy again. It's a vicious cycle.