Something cutting/eating dendrobium
 

Hi guys. Last week I noticed that something had "cut" a young leaf off my dendrobium. One of the shoots also looked like it had been snipped across the top. Didn't suspect bugs because the cut looked so even and clean like it had been cut with scissors. Yesterday, noticed another shoot and leaves with curved bites and a hole. Brought the plant in from my second floor patio and sprayed plant and medium heavily with Dr. Earth Insect Killer (natural oils) hoping to draw whatever it was out. Nothing came out of medium or moved on plant. This morning, also soaked the medium in water with nothing coming out. I've noticed one or two dead white caterpillar/grubs in my water containers on the patio a few times. Could it have been caterpillars? None of my other orchids seem to be eaten. Thoughts? Experiences? I live in NE Iowa btw. Here are some pictures.

Oh yeah, he is dining on your Dendrobium.

I would unpot, throw the medium away in a place where there are no plants (in case Mr. chompers is hiding in the medium, totally wash down the plant by spraying in cool/tepid water dry it off a bit (air it) and then apply your insect spray. I would then worry about any plant you had near that plant if any.

It does look to me like some kind of hungry larvae, but I would not know what. In the meantime, don't leave it to chance.

The growths will (most likely) still grow, they will have a scraggly appearance because the tops were eaten.

I don’t know if slugs or snails are a possibility where you live, but they did a number on one of my Dendrobiums. I was able to go out at night with a flashlight and catch them in action. I did pretty well killing them off, but periodically new ones would come in and attack it again. I ended up hanging the plant to keep it out of reach: maybe next year I’ll get to enjoy the flowers instead.

Handing seems to keep snails out of plants, but not necessarily slugs. (I swear they fly...) I have found them in hanging plants. I suspect that the little devils crawl up supports and down the hangers. Caterpillars are likely candidates in this case... they can totally disappear - go onto another plant, or even pupate and fly away as a moth or butterfly. For caterpillars and similar larve, a formulation of BT (bacillus thuringiensis) can be used... completely non-toxic to everything except larvae, which stop feeding when they ingest it. Works on tomato worms too...

Roberta! Tomato worms turn into beautiful spinx moths! We always let them have a plant. ( A friend used to douse them in gas and burn them yuk). Lol be

How do you make sure that they stay only on the one plant? Or if you have only one plant? (Also, those moths may be regional)

Well, Roberta...one plant? Really? Don't you know "one for the cutworm, one for the crow, one for the rabbit and one to grow." You must have 4 plants according to Grandma. So, accordingly, the OP clearly needs 3 more orchids. 🤣

Ha! Thanks for the replies guys. I do suspect the caterpillars, which I think are likely moth caterpillars. Saw one drowned in a bucket and another dead on the floor of my patio before. I've had slug infestations in the past when my orchids were in the backyard. Now they're on the second floor and I haven't seen any slug/snail trails. Also sprayed the orchid and sprayed, soaked the orchid medium pretty well, inspected it at night and didn't see anything crawl out. Will have to inspect my other orchids but a quick glance did not reveal any similar damage.


Roberta and Dolly, butterflies and moths are beautiful. Saw a hummingbird moth visiting my patio orchids last summer and was super excited. I was really disappointed when it didn't feed from my blooming dendrobium, which was the only thing in bloom at that time. It must have just been checking out the plants. Didn't know they existed in the US. Only other time I've seen them was in SE Asia. I used to catch caterpillars as a kid, keep them in jars, and feed them in hopes they would turn into butterflies/moths. In this instance, I do have more than one orchid but I'm not going to share :) They are too slow growing and precious. Will likely toss the caterpillars off the balcony onto the grass/plants down below. They can have those :) They can share with the rabbits and crows that also live around here.

grasshoppers eat my orchids if they get in the greenhouse....I go nuts in hunting the devils down!

That would be frustrating. I'd think you could see them hopping or flying when you get close though.