Flea beetle weapon other than row covers and pyrethrin?

My veggie garden is regularly hit hard by flea beetles, especially arugula, cabbage and broccolli. They can kill small seedlings. Badly weaken larger plants. They don't bother my nearby perennial garden.

I can't cover my whole garden with row covers, especially since they need to be pinned down tightly all around (covered with dirt). I had a little success last year on a small batch of arugula, but total failure this year when I didn't seal all edges. Pyrethrin seems to kill them, but you have to hit them with the spray. So I spray the grass around the garden and plants with bettles sometimes twice a day.

Is there another approach??? What do professionals do???

TIA
LAS

I had always heard that the best approach was to spray with neem oil soap, which has bacteria that will kill the flea beetles but not beneficial bugs or hurt the plants. I think it may be a problem for bees, though. This spray is a short term, quick response, but the longer term solution is to put beneficial nematodes in the garden. (You have probably heard of nematodes as a bad thing in the garden, but not all nematodes are created equal. You can buy beneficial nematodes for long-term control of flea beetles and other bad-for-veggie pests.

But...I have just had a flea beetle attack myself and read that the newest and best approach (new since the '80s, but not well-known yet) is Spinosad, a bacteria that they say is as effective as synthetic pesticides, but it is so safe that organic farmers can use it and still call their plants 'organic.' I just bought a bottle of the concentrate, packaged as Captain Jack's Deadbug Brew (there are other companies who also sell Spinosad concoctions), and sprayed it on my nightshades on Thursday. When I checked them on Saturday, the problem appeared to be solved.The plants had grown a lot in 48 hours, with no more flea-bitten leaves. They looked great.

ShaynaPearl, thanks! I do have some Spinosad. Will try it right away, and will investigate beneficial nematodes. Thanks again!

LAS

I just treated my garden with Spinosad also,... I purchased the "Potato Beetle" formula,.. it contains two types of Spinosad which listed all the contents of my Garden,... Celery, potatoes, cabbage, Brocoli, Beans, cukes, Tomatoes, lettuce, onions, radishes...

I did this yesterday after 3 days of hard rain,..... we'll see...?

I know the three days you're talking about. I sprayed with Spinosad the day before, but we had to come back to Boston on Friday, before the rains finished, so I'm worried that only 24 hours of Spinosad may not have gotten all the flea beetles. I'll be very interested to hear about your results!

LAS

The Spinosad seems to be working.... my cabbage, potatoes, broccoli, beans, peppers all seem to have much less insect damage,...I also used the DE (Diatomaceous Earth, in the powder form) around all of the plants in the garden,... it took a while to put in place,.. but the crawling bugs (earwigs, ants, etc,..) have been thwarted,.. at least for the time being...

This message was edited Jun 29, 2011 12:15 PM

I guess you can't tell if you put down both Spinosad and diatomaceous earth. But someone said somewhere that the diatomaceious earth has to be dry to work. Has yours gotten wet yet?

I also read recently that even Spinosad has to be applied every 4 or 5 days because new generations of flea beetles arrive. How long since you applied yours?

I do believe it's working pretty well for me, as new growth hasn't been attached very much. But we came back to Maine after being away forabout five days, and there are some flea beetles still to be seen. But not on every plant.

LAS

OK, here's my latest report. I sprayed with sponsad 10 days ago and then came 3 days of rain within 24 hours. We got back to our summer place 2 or 3 days later and the beetle damage was way reduced. Lots of new growth had none. I didn't see many beetles. So I sprayed with Spinosad. This was two days ago. This a.m. I saw that a lot of plants (not all) had flea beetles on them. But they were pretty much confined to already badly damaged plants. (I have heard that insects prefer weakened plants). So I sprayed the beetles I could see with pyrethrin. My understanding is that Pyrethin kills on contact, whereas spinosad needs to be ingested. I am hoping that Pyrethrin kills quickly while Spinosad may take a few hours or a few days. So the combination may be reasonable. But I don't know and couldn't find out on the web how long either actually takes to kill a bug.

LAS

Here's some info on Spinosad that you may find helpful: http://web.pppmb.cals.cornell.edu/resourceguide/mfs/13spinosad.php Sounds like for flea beetles you're going to need to reapply several times since their populations can re-establish quickly.

LAS,... the spinosad seems to work temporarily on the cucumber beetle,.... I pick them off morning, noon and nite and have applied spinosad about every 4-5 days,.. per instructions..... ad I apply it at dusk..

oh,... the discussion regarding the DE (Diatomaceous Earth).... I purchased a bag in the powder form, placed it in a squeezable ketchup bottle and applied it to the dry soil,.... it stayed dry for two days before the rain,..... but it worked,... I eliminated the huge pobulation of ants that were a problem,.. now the :good ants are back ad eating the aphids from my fennel,... so mission accomplished..

Oh,.. I did re-apply to my sage, basil and oregano,... now all is fie there too...

I just now realized. Spinosad is the stuff in Comfortis for dogs. Weird.

Just this morning I responded to a post about Comfortis in the Vegetable Gardening forum:

http://davesgarden.com/community/forums/t/1194513/