Can you post the links to this information? My understanding is that pillbugs and sowbugs almost always eat decayed plant material and not live plant material.

From Northern State University in South Dakota.
Pillbugs form an important component of the larger decomposer fauna, along with earthworms, snails, and millipedes. All of these animals return organic matter to the soil where it is further digested by fungi, protozoans, and bacteria, hence making nitrates, phosphates, and other vital nutrients available to plants. Although they may occasionally feed on roots, pillbugs do minimal damage to live vegetation and should not be regarded as pests.

Steve

Here is a link that might be useful: Pillbugs, sowbugs and woodlice.

I'll have to find it again, Steve. They have never been a problem here before and that is always what I thought, until this year, but they have made a believer out of me! They have actually eaten some of my yoing hostas to the ground and even attacked mature ones, eating away at the stems until they are severed. I have gone out to look and seen young hostas covered with hundreds of them at once.

Sandy

Spinosad! It's approved for organic gardening.

-Babka

Wow, Sandy. You must have a special breed of hungry Pillbugs. Babka's right. Spinosad should take care of these guys.

Steve

Actually upon further thought, first having dismissed the "in balance" statement as a New Age-y kind of thing, that is most likely what it is, and I probably caused the problem myself.

I know how the natural world does easily get out of balance, predator and prey, habitat, etc. We have the same thing here with the explosion of the rabbit population, due to the disappearance of the local red-tail hawk contigency--why they are gone is a mystery to me unless it is related to the tornado last year, loss of habitat, etc. Anyway, back to the pillbug problem.

Last year we devided.to clear out an area and build a new hosta bed. The poor rock soil beefed built up, so we brought in a load of mushroom compost, about 6" thick of the stuff, and topped it off with about that much leaf compost, then a layer of shredded leaves on top of that. Fine. It sat over the winter, shrunk down to about 3", and we planted in it. Everything else was fine, but the tender young hostas were soon under attack by thousands of pillbugs.

Apparently, all that rich, damp, tasty organic matter caused an explosion in the pillbug population, combined with a nice wet spring and our high humidity, and now these normally beneficial crustaceans are munching on everything in sight, live plants included. If I had waited one more year, the population would probably have balanced out as the rich food supply dwindled, and we would not be having this conversation, lol! They are ONLY attacking the hostas where we put down all that compost.

So it's my own fault.

This is not my phenomenon alone, somewhere on the forum there are threads about pillbugs attacking and destroying live plants. They may be workhorses as far as eating decaying matter but in certain situations they can be as bad as or worse than slugs and cutworms. I'll find that thread and post a link.

Sandy

my little tablet computer won't cooperate posting the link but if you go to the garden pests and diseases forum on GW there is a thread about pillbugs with pictures. The first picture looks kinda like what they can do to a hosta, and elephant ears as well! I can't find the link right now that made the statement about them sometimes being a problem in the southern states, but I will keep looking.

I have been using diatomaceous earth, which helps, but there is a spider that preys on them and I hesitate to use even that as it might kill the predator as well as the prey, which would contribute even more to the imbalance problem.

I don't use any other chemicals. Even organic ones. Sometimes organic as toxic as anything Monsanto can come up with. And non-selective, kills the good along with the bad.

Sandy

Well,I'm in the south and the only place pillbugs ever appear is under my watering cans,when I set them down on my concrete driveway. Never have seen one in my garden. Phil

Everything is made from chemicals. Some are naturally occurring and some are synthetic. But, of course, I know what you mean and understand you point of view.

Problem is that it's hard to use a barrier because the pillbugs live in the soil and probably are eating roots. I know you are overrun with pillbugs, but are you sure they are the ones doing the damage? Have you seen any earwigs in the foliage? It's not unusual for pillbugs to be blamed for the carnage caused by others. Try the rolled up newspaper trap trick and see if you catch any earwigs.

Steve

Spinosad IS selective. Check the link.

-Babka

Here is a link that might be useful: Spinosad IS selective

No earwigs. And yes, I have seen the hostas literally crawling with pillbugs, colonies of them. Not many slugs as the turtles do a pretty efficient job on them. I went looking the other night with a flashlight and on all the hostas I found maybe 5 small ones.

Yes, it is definitely the pillbugs. I would have been skeptical too had I not seen them in action myself as I always the one hat said they were harmless.

Phil, I hope you never do see them!

Sandy

If you don't wish to take any actions to dispatch them (pill bugs), I guess you must just sit and watch what happens. Actually the hostas will probably do just fine, perhaps a bit smaller next year, but losing a few leaves or even going heat dormancy doesn't kill these beauties. Your choice.

-Babka

Sandy,

Would you consider using Neem? Or how about a summer weight oil like vegetable oil? If you can see swarms of these guys it should be easy to coat them in oil.

The only other possibility I can think of is to try to trap them with some decaying organic matter. Sink a shallow plastic container into the garden and put some rotting vegetation in there to attract these guys. In the morning see how many you have attracted and drop them into a container of soap and water.

Other than that, Babka is right, just watch what happens.

Steve

Well if there is one thing I've learned, it is to be more patient and not get in a hurry with mushroom compost. In the future it is going to sit for a couple years before I plant hostas in it!

I think I'll adopt a wait and see attitude, and keep using the diatomaceous earth. I see lots of spiders, more than normal (response to the increased amount of available food?) And there is one that preys on pillbugs--odd looking spider, I've watched it in action, so maybe Nature is taking care of the balance problem without my help.

I may have to start over with some of the younger hostas--we aren't talking a leaf or two, but the entire plant--and I will know better next time.

Sandy

Well, as my dear old grandfather used to say, "Hindsight is 20/20".

bkay