Spinosad & Bt with bees

owiebrain(5 MO)May 12, 2011

I've sprayed my brassicas with both of these, thinking it was completely safe for the bees. I was sure I'd read that... somewhere.

Tonight, I stumbled upon some comment somewhere saying that Spinosad was, in fact, highly toxic to bees. A bit more reading and I'm fairly confident in my continued use as long as I do it in the evenings, when the bees are not out & about. It seems it's not such a threat to the bees once it has dried.

Now I'm reading on Bt and it's not looking quite so promising. There's a heck of a lot of conflicting info and I'm having trouble sorting it out.

They are the only two things I have ever used (other than a crazy, ignorant summer with Sevin, long, long ago...) -- and the only way it seems I can grow brassicas. I just tried Spinosad for the first time last year and this year is my first trying Bt.

What are your thoughts on both of these, especially in regards to bees? I think I'm most concerned with Bt at this point.


Thank you for reporting this comment. Undo
sammy zone 7 Tulsa

BT kills caterpillars that are on the plants, but does not remain to keep on killing.I don't remember what else it kills, but there are always small good guys that can be killed by any of these products.

I think Spinosad is potent. It may be "people safe", but as far as the balance in the yard, I think it is the one I stopped using for thrips. Again, these products kill many pests in the yard.


    Bookmark   May 12, 2011 at 7:44AM
Thank you for reporting this comment. Undo
joellenh(6b Jenks)

Are there different kinds of BT? I use Bacillus thuringiensis (Safer Caterpillar killer) on tomato hornworms and tent moths. It is my understanding that the critter has to actually eat and ingest the leaf sprayed with BT to be harmed, and that it only affects leaf eating caterpillars and has no impact on bees or other beneficials.

My other weapon of choice is neem, and I am almost positive that is bee-safe.

So far this year I've just used a little bit of neem on my tomatoes which are full of pin holes on the bottom leaves (spider mites)?


    Bookmark   May 12, 2011 at 8:37AM
Thank you for reporting this comment. Undo

I would think you're safe the way you are using it. I don't know if BT, fed directly to honey bee brood, would hurt anything. But I doubt that your broccoli is much of a pollen source for your bees.


    Bookmark   May 12, 2011 at 10:38AM
Thank you for reporting this comment. Undo
Okiedawn OK Zone 7


I agree with George that with the way you spray them on brassicas, they shouldn't be harming your bees. That might change if you sprayed after your brassicas bolted, though, and bees were attracted to the flowers.

Because spinosad is more of a broad-spectrum pesticide, I don't spray it in a liquid form out of fear it might hurt the various kinds of beneficial insects I depend upon for pest control. I only use it in two different granular formulations....for sow bugs and pill bugs in Slug-Go Plus, and in the form of Concern fire ant killer which is used in various brands of organic fire ant killer products.

I haven't looked at research on spinosad and bees so have no idea what the official position is.

With Bt products, each formulation is "supposed to be" specifically toxic to a certain kind of insect. For example, Bt 'kurstaki' affects Lepidoptra, Bt 'israelenis' affects Diptera (flies and mosquitoes) and Bt 'san diego' affects leaf beetles (Coleoptera). I think there are other forms of Bt products but I haven't used them and don't know much about them. However, I also don't know if they have been researched with regards to bees. I would think that since the CCD issues arose the last 4 or 5 years or so that it is likely some research entity is studying the effect of both Bt and spinosad on bees and its possible role in CCD.

I no longer spray either my potatoes or brassicas with Bt products. Instead I just rely on hand-picking/destroying the pests. The older I get, the less I use any pesticide product, whether synthetic or organic in origin, out of concern for the ecosystem as a whole. I do still put granular Bt 'israelensis' in my rainbarrels to kill mosquito larvae. We often fall into the trap of thinking that products of natural/organic origin are safer than products of synthetic origin, and we are constantly proven wrong. Many so-called 'safe' organic products we used years ago like rotenone, pyrethrum and sabadilla are now linked to various health-related issues and I haven't used any of them in about a decade.

Correct me if I am wrong, but isn't one form of Bt used to control wax moths in bee hives? I find it hard to imagine that it is used in that manner without being thoroughly tested.

One thing we cannot forget, ever, ever, ever is that Bt is being inserted into GMO crops. What unknown results could that have? Once they start messing with Bt strains, are those strains the same as we've always known them, or are they somehow altered? And, if altered, are they then dangerous in a way they weren't before? Those are issues that bother me. I worry that the once seemingly-innoculous Bt strains could be manipulated into something else. (sigh)


    Bookmark   May 12, 2011 at 11:48AM
Thank you for reporting this comment. Undo
owiebrain(5 MO)

Thanks, all, for your input.

My spinosad is in liquid form but I only spray it in the evenings and only on the brassicas a couple of times. It's not like I'm spraying willy-nilly all over the place and during the middle of the day, so I feel fairly safe continuing it. At least until I read something different. LOL

The Bt, though, I just don't get it. I thought it was harmless to bees, only targeting very certain things, as mentioned above, but then I read several pages saying it caused bees and other beneficials problems. And, yes, I've also read that it's used to control pests in hives, too. That's why I'm not making heads nor tails of it. I need to just pick a day when I don't have distractions and dig through the (as much as possible) objective science of it all. Unfortunately, that won't happen until the kids are 40.

Dawn, that's something else I ran into today -- learning that they're using Bt in GMO stuff. Wha?? Holy cow, as if I didn't have enough trouble keeping up with this stuff already.

I'm glad I don't use anything at all elsewhere in the garden and hope I never have to. Brassicas, though, just don't have a chance without some help, in my experience. I went years and years without growing them because of the unbeatable pests (without chemicals) but gave it another shot with cabbage last year after reading about spinosad here. It was so successful, I've been slobbering all over myself ever since, hoping I could grow broccoli, cauliflower, etc. If it boils down to it, I'll once again give up my dreams of growing brassicas but, dang it, I don't want to if there's a chance.

Dawn, I think you know I'm with you on the "organic" label. Maybe it used to mean something and I'm sure its intention was originally a good one but it's meaningless to me now. Yet hope springs eternal so I want to believe that there are at least one or two treatments out there that are tolerable to me. I know it's a very personal choice, what to use or not use in our gardens. I know lots of folks think people like me are just being paranoid, overly cautious. I know lots of folks think people like me are not being cautious enough. Different strokes and all that, I say.


    Bookmark   May 13, 2011 at 1:37AM
Thank you for reporting this comment. Undo

Neem oil will hurt any bug, good or bad, if you spray it directly ON them. Neem works by short circuiting the insect's brain chemistry and makes it forget to eat, thus causing it to die of starvation. But as long as you're not spraying it willy nilly, the bees will be fine.

I'm sure people get tired of hearing me talk about it, but I believe in using essential oil sprays for pest and disease control. If I ever had a bad outbreak of a pest or disease that my homemade spray couldn't cure, and if hand picking the insects off the plant didn't work, I might use Bt or copper or sulfur or spinosad, but it would depend on what crop was sick, how much of it was sick, and how badly I wanted it. I think with organic gardening, you have to adopt a sanguine attitude. For example, my dog trampled three of my baby cabbages a few days after I planted them. And I just shrugged it off and chocked it up to experience. These things happen. The heat also killed my broccoli, but what can you do? I think you can work with Mother Nature, but you shouldn't work against her and if that means you loose one or two plants to insect or disease, then it happens. Gardening, the weather, life...nothing is ever certain; you just have to go with the flow. Which, in my humble opinion, is better than poisoning the planet. But as Diane said, different strokes for different folks. :)


    Bookmark   May 13, 2011 at 6:57AM
Thank you for reporting this comment. Undo
Okiedawn OK Zone 7


I agree with you about the way organic products are being 'corrupted' in a sense.

For example, I've always used DE for some crawling insects and have recommended it to others for the same purpose, Then, 3 or 4 years ago I found, on the shelf of a local big box hardware-type store, a cannister of DE to which an chemical insecticide had been added. Grrrr. After that, I had to be sure to recommend only DE that was pure, food-grade and to which nothing else had been added. Know what? Going through that whole extra explanation got tiring so I pretty much just stopped mentioning DE.

The Bt-engineered crops bother me just as much as the Round-up resistant crops. When "they" started making all that stuff, we knew exactly what would happen---we knew we'd start seeing Bt-resistance in pests once controlled by Bt, and we have, and we knew we'd see the emergence of glyphosate-resistant weeds, which we also have seen occur. Sometimes I think industry needs to learn when to leave well enough alone. The more that industry takes our effective pesticides and 'corrupt' them, the less I use them.


I use neem occasionally but try to avoid oils in the garden in general. I have a really large garden and never could hand-pick and manage all the pests alone. I rely upon a wide range of beneficial insects to do that for me. Any oil product, if sprayed when the beneficials are present in the garden, can smother them, so I just choose not to use it. I find beneficials in my garden 24/7--they live there, eat there, raise their young there, and even though they are less active extremely early in the day, they are still there. I don't want to do anything to harm the beneficial insects that help control pest insects. This year my beneficials are doing a great job with pests so far, which is a relief because last year was a horrible pest year.

Diane, For brassicas, I've switched to growing under row covers, and I'm happy with that so far since I hate hand-picking all the broccoli worms and choose not to use Bt any more. If tomato hornworms were a major pest im my garden, I'd likely have no choice but to spray the tomato plants with Bt, but I rarely have hornworms on my 100+ tomato plants. I "think" there's two probable reasons they don't bother my plants much. First of all, because the fields here are full of native nightshades they can visit instead and, secondly, because the native parisitic wasps control them.

I have been 98% organic for about 12 or 14 years now, but I'll likely never be 100% organic because I reserve the right to use chemical herbicides like Round-up occasionally, although I use them only once every few years, and also a chemical fire ant killer, which also is used only once every 2 or 3 or 4 years as needed.

I think that the next time we have a horrid grasshopper invasion like we had last summer, I'll likely try EcoBran for grasshopper control. It has a small amount of Sevin in a bran bait and would affect only the critters that ate the bran, which would be mostly grasshoppers. Last year, grasshoppers ate my beans down to the ground, and stripped all the tomato plants in the Peter Rabbit garden of all their foliage, flowers and fruit in just a couple of days. Then they moved into the big garden and started doing the same. When you are in a rural rangeland area where hordes of adult grasshoppers migrate in from elsewhere, there's no good organic solution. (With drought in all of Texas this year, I'm really worried their grasshoppers will come here this summer, which they already did during one specific week in March 2011.) We had probably a thousand times more hoppers last year than my chickens could eat, and even the agricultural producers around me concede that the sprays they use for grasshoppers don't seem very effective on mature adult hoppers. I use Nolo Bait or Semaspore when grasshopper nymphs are emerging in April and May and it controls them just fine, but it is significantly less effectve on adult hoppers. Rather than lose my garden to hoppers if they show up this year, I'll use Ecobran.

So far, it isn't a bad pest year, knock on wood.

The Colorado Potato Beetles showed up and then the spined soldier bugs showed up to eat them. In fact, to be honest, I first saw the spined solider bugs and then 4 or 5 days later I saw the first CPB. I think it is likely the CPBs were hatching out first, but the spined soldier bugs were eating all of them before I ever saw them. I still have found and hand-picked a few to squish and kill, but I don't hand-pick all of them because the spined soldeir bugs will leave if they aren't finding a food source. This is completely different from last year when CPBs showed up by the hundreds and I never saw a spined soldier bug at all.

It looks like it will be a bad blister beetle year though. They are showing up in May in huge numbers, and usually I don't see large numbers of them until July or August. I guess it is always going to be something though.

Spider mites showed up early too, which was not unexpected given that we have had some really hot days in early and mid spring. However, I just ignored them, and now I think the beneficial mites or some other insects, maybe the lady bugs, are eating them because the spider mite population doesn't seem to be increasing and may be decreasing.

Mosquitoes are here now too, and I'm not real thrilled about that. Ditto for the snakes. We had the first one close to the house this week, and shot it. We have zero tolerance for venomous snakes, and also zero tolerance for rat snakes and chicken snakes in the poultry housing.


    Bookmark   May 13, 2011 at 9:09AM
Thank you for reporting this comment. Undo
owiebrain(5 MO)

Ah, Dawn, you reminded me that I'm not as hands-off as I made myself seem. I, too, have judiciously used Round Up -- one year, carefully hand-painted on Johnson grass-- and I'd do it again. Also, I've used (food-grade) DE both in the garden infrequently and regularly on our chickens.

So, I'm not really lily-white in the pest department but more of a light beige. ;-)

I've used row covers in the past, on eggplants. Worked great but it was a pain. I started typing that I'll never mess with it again but, well, maybe I'll revisit it again for brassicas. I'd not thought of using it for them.

I'm rather nervous about pests here. I still don't know what herbicides and pesticides they use in the cornfields that surround us on all four sides. I'm sure they must use them but not what products and to what degree. If I ever get to catch the farmer for a chat, I will pin down a few answers. I'm worried that the pesticides are rather broad and I'll have a terribly low level of beneficial insects. On the upside, that probably means there's also a low population of the bad guys as well. I just know things are probably out of whack and that's not what I want.

It's the not knowing that's making me nuts. LOL This year will definitely be one of observing, taking notes, and learning to adapt. Anyone sell patience in a bottle? I'd be willing to pay!


    Bookmark   May 13, 2011 at 11:10AM
Thank you for reporting this comment. Undo
Okiedawn OK Zone 7


I know very few people who are always 100% organic. There are just times when the best answer, for example, is a chemical herbicide (Johnson grass and bermuda grass fall into the category where Round-up may be needed, for sure) because there is not a really effective organic solution in some situations. And, there are times you need to deal with a dangerous pest...like black window spiders, for example, and need the most effective pesticide, whether it is organic in nature or not. You know, it is easy to be 100% organic "in theory" and much more difficult in reality. I just try to be as organic as possible and to try always to work with nature to the extent that I can, instead of against it.

Somes an organic solution you're not expecting finds you. For example, I'm not sure I've ever read any place that turtles like to eat Colorado Potato Beetles, but for three years I had a turtle in my garden who'd spend the whole day (slowly) traveling up and down the potato rows and eating all the CPBs it could find. And even though I've always enjoyed having damselflies and dragonflies around, I didn't know for ages and ages that they were helping us by controlling mosquitoes.

I've been wondering what effects you'll see from being in a farming area. I suppose only time will tell. I expect they will be using broad-spectrum pesticides and you may find it difficult to maintain healthy populations of beneficial insects. Once your one million trees have grown for a few years and sort of act as a windbreak/pesticide break, I' hoping they'll either reduce pesticide drift onto your property or help shelter your beneficials from the pesticides.

I know this will be a very adventurous year for you, and if had any extra patience, I'd send it to you, but I don't even have enough patience for myself.

I know there are people who garden organically even in farm country in the midst of lots of chemical usage, so I know it can be done. You just won't know what to expect until you've had a year or two to see what happens. If your farming neighbors are raising corn and are using Bt-corn or Round-Up Ready crops, they may use less chemicals than you're thinking they might because their chemicals are essentially "built in".

Being protected on three sides by trees has made it pretty easy for me to garden organically with little fear. I only have trouble occasionally when the rancher due east of us pays someone to come in and spray his pastures with a broad-leaf weedkiller and the wind happens to be out of the east that day. Luckily, wind out of the east is somewhat rare here, so I only get herbicide drift damage once every 4 or 5 years.


    Bookmark   May 13, 2011 at 12:18PM
Thank you for reporting this comment. Undo
helenh(z6 SW MO)

Tomatoes don't make me sick early in the season, but for the last two seasons I can't eat tomatoes in summer. I get a digestive disturbance bad enough to make me limit the amount I eat and after a while I usually stop eating them. It could be overdose because I often eat tomatoes breakfast, lunch, and dinner. I have begun to suspect something I spray on the tomatoes or stinkbugs. I don't spray anything until I start getting caterpillar damage that causes the tomatoes to rot. I usually try to find the big green hornworms that mostly eat the foliage. Sometimes when they are bad I spray for them. It could be possible the stinkbug leave a residue of some kind that I am allergic to. I have been overrun by stinkbugs. The chemicals I use are Bt and spinosad and Surround. I don't suspect the Surround because I haven't used it that much.

    Bookmark   May 13, 2011 at 1:12PM
Sign Up to comment
More Discussions
Anyone ever read the Soil forum?
Hahaha, I went over to go check out how they were doing...
Problems/successes germinating
Since all I am doing right now is sowing and waiting...
Squash Resistant to Squash Bug and Squash Vine Borer
According to Jay White at Texas A&M University,...
Growing cilantro in the summer
I started some cilantro from seed so I can have it...
Seedy Saturday Seed Swap
Seedy Saturday Seed Swap. February 28, 2015 When I...
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™