I'm overwintering three red bananas in the basement, where the temperatures are in the 50's/60's. They're in the dimmest of light and get a scant cup of water each month. Two are fine and producing new leaves. One is limp looking and being chomped. It has a couple of leaves that seem fine, though limp. I saw a hole through one stem about the size of the tip of a Q-Tip. I didn't get a picture of it, but I cut it off. The holes on the stem in the image are roughly the same size. Maybe a bit bigger.

Help! Seems like a borer? Organic ideas (have neem and Bt at my immediate disposal).

Does the damage increase with time or is it stable? Also do those black borders appear to be increasing in size?
Unless you have a snail or slug hidden around the basement (possible, but usually they leave slime trail behind them) personally I lean towards something different. If the plant has limp leaves it's probably something more serious than a snail having a snack.

Need a little more data.

The black-edged bite marks I only really looked at today- it was turned away, and it was only today that I noticed that the other two were very clearly vertical and this one was wilting. I expect wintering bananas to look sort of lousy, so I didn't realize this one looked particularly lousy.

I didn't get a picture of its overall form but it has one or two leaves left and it's drooping. I'm worried that something is eating the roots and the hole worries me. Otherwise I'd think maybe I had an overwintering slug, as you suggested. I peered into the pseudostem and didn't see anything.

As far as increasing over time -- yes, I think over a month or so and it only just became clear enough that I decided to look closely. I think there are more of those black bite marks. If I noticed them earlier it was probably just to think that it was old summer damage.

There are no other plants in the basement other than these three. It's cool and humid, and they have very dim light. They've been down there a little over three months.

I feel like I should get it in good light, dump the soil, and find whatever it is but not having any idea what I am looking for, other than that it's big, lacks appeal. I've done internet searches but haven't found any images that look quite like that.

I did not see any bug poop, but I also didn't hit it with full light, nor did I get a magnifying glass, because the 'not knowing what it is' of it it all gave me something of the creeps.

Also, it seems more interested in the stems than the leaves.

Maybe a "pseudostem weavil"?

Maybe this charmer? My eyesight is not great, nor is the picture.

I think it is Odoiporus longicollis and I don't think I can save the plant.

I cannot make out what that thing is.

I have never seen a Pseudostem weevil (Odoiporus longicollis) in my life, nor I am aware of it have it ever been reported as breeding in the US. From the literature I have it seems to be confined to Asia for the time being, with a few apparently eradicated cases in South America. The literature also states that "gum exudates" (tiny sticky black spots which congeal in masses) are the most important signal of infestation and I don't see that.
So unless you bought your Red bananas in a country with a well known Pseudostem weevil problem (which USDA quarantine procedures didn't catch) I would rule that out.

Personally the sagging stems lead me to think the problem is likely tied to growing conditions: is that plant near to a door? Or any other cold draft? Even hardy bananas will ultimately be killed by continuos cold drafts. It would also be a good idea to check the growing medium, especially at the bottom, for soggy soil. Bananas love their water but hate having soggy feet.

I can't identify it, but stealed myself and performed surgery. Photos below. The metal object is an ordinary steak knife. You can see very small larvae in the cell structure and what I think might be a weevil. I'm including the two healthy bananas--they're in the same conditions and while I know New England basements aren't their thing, they seem to be tolerating it well enough.

The third, infested one has been removed to the garage.

In order to figure out what was going on I had to cut it down to about three inches so I don't know if it will survive.

I am very relieved whatever it is, it's not that pseudostem beetle because those things grow an inch and a half long and FLY.

Bonus larvae on tip of steak knife.

*shudders*

Sorry I'm posting so much, I'm pushing through being seriously creeped out.

I feel your pain. I just endured my own infestation. Mine was European Pepper Moth larvae and now I know a lot more about them than I ever wanted to. The plant in question is super dead.

Not sure what your creepy crawlies are!

I would get it out of the pot and rinse off the soil around the corm. Cut off the leaves, bananas do not need leaves in the winter and clean it up well. It will re-leaf quickly if planted when the weather warms.

We all have issues with creepy crawlies at times. Earlier this year I brought in bark beetles that had infested an orchid mount. I was afraid I had termites in it and I soaked the whole thing to see what floated up and these horrible, huge beetles emerged. Yuck. It happens.

Damage to the stem tissue looks minimal: this is most likely an opportunistic leaf/stem miner larva that was trying its luck. It happens all the time, even with Hippeastrum which is a pretty pest-free plant.
Regardless, it wasn't enough to cause the effects you have seen: pests always prefer attacking the weakest plants so there is something else at work.
Personally I still lean towards a physiopathy.

ElPolloDiablo said:Damage to the stem tissue looks minimal: this is most likely an opportunistic leaf/stem miner larva that was trying its luck. It happens all the time, even with Hippeastrum which is a pretty pest-free plant.
Regardless, it wasn't enough to cause the effects you have seen: pests always prefer attacking the weakest plants so there is something else at work.
Personally I still lean towards a physiopathy.

The weird thing is, they were all treated exactly the same, and this one was in the middle. Although now that I'm thinking about it...maybe being in the middle led to this one being less successful at evaporation.

I was giving them the same amount of water -- if I'm remembering correctly, none since November, about four ounces in December, and then recently eight ounces.

So I wound up cutting everything infested I could find, cleaning the best I could, and have brought him up into my office which is relatively warm and has good light. The pseudostem center is protruding a bit more each day (what an awful sentence!) and I'm going to leave it unwatered and just see what happened. I'll get the others in the basement off the ground so there is air flow underneath, just in case that helps them though they seem ok.

Thanks so much everyone. Maybe he'll surprise me and live!

ElPolloDiablo said:I cannot make out what that thing is.

Bananas love their water but hate having soggy feet.

I'm embarrassed to provide this update but leave it here as a warning to future generations.

I brought the bananas upstairs indoors to encourage the growth that had begun again in the basement. Over a few weeks, I lost another, and have one relatively healthy looking one remaining.

To see if there was anything salvageable in the second victim I took it outside and dumped the soil. The top five inches were bone dry. The bottom five inches were soggy.

I had potted them up in pots with....I wish I could whisper this....no drainage holes. None. Whatsoever. Somehow they lived through last summer, outdoors, in those containers, but maybe because they were in the sun and putting on strong growth, I got away with it.

Nothing salvageable in my second victim but have reseated the survivor in a shallower, wider pot with generous drainage holes.

How embarrassing. It absolutely looked and felt like overwatering but because the top of the soil was so, so, so dry I didn't think it could be the case.

I leave this post as a cautionary tale.

I did that exact same thing once. I had invested big bucks in a ceramic pot and must have noticed it did not have drainage holes but I came home and put it aside for a few weeks and the lack of drainage skipped my mind. When a fairly valuable plant I had put in the pot began to suffer I removed it and saw my mistake. Got the drill out and quickly remedied the situation. replanted it and all was well except for my embarrassment.