Beesource Beekeeping Forums banner

1 - 12 of 12 Posts

·
Registered
Joined
·
1,660 Posts
Discussion Starter · #1 ·
Was looking for the regular powdered form of BTA and came across a liquid form of BTK its a smaller size and half the price but a different strain , having a hard time finding BTA in liquid form here is one but its out of stock and not in the usa https://www.amazon.co.uk/XENTARI-BIOLOGICAL-INSECTICIDE-BACILLUS-THURINGIENSIS/dp/B00W98HXTC Does anyone know if the BTA is available in liquid form in the usa and would be a better option not sure of shelf life yet
 

·
Registered
Joined
·
124 Posts
Btk isnt what you want. You need bta. just get the powdered form. You know you still have to mix most liquids too it isnt pre mixed most chemicals come in concentrated form and you mix it in oz per acre or oz or weight per gallon. Just get the dry form. Only problem ive ever had using dry chemicals is if you leave captain mixed up more than a say it will clump in the bottom of spray tank amd is hard to get out but with bta you shouldn't have to mix any more than a few gallons to spray frames. Just put the powder in a zip lock bag it shoukd be good for more than a year as long as it doesn't get wet
 

·
Registered
Joined
·
1,669 Posts
BtA and BtK both kill Lepidopteran insects which wax moth larvae are.You can use either one.Some use Dipel and Thuracide witch both are BtK with good results.BtA was once and may still be labeled for honeybees but Bk isnt.Both work just as good.
 

·
Registered
Joined
·
1,316 Posts
BtA and BtK both kill Lepidopteran insects which wax moth larvae are.You can use either one.Some use Dipel and Thuracide witch both are BtK with good results.BtA was once and may still be labeled for honeybees but Bk isnt.Both work just as good.
This article from Syracuse Beekeepers says "Some other strains of Bacillus thuringiensis (BtK) are toxic to bees and humans, so beekeepers must resist the temptation of using other BT products. Do not use the Bacillus thuringiensis subspecies kurstaki , or “BtK”, use the subspecies aizawai,"

Now part of that appears to be grossly incorrect, as BtK is approved for use in treating sweet corn for corn earworm, is even labeled as organic for such use, and is approved to use up to day of harvest, so it's highly unlikely to be toxic to humans.

But have we established that BtK is _not_ toxic to honey bees? Has anyone here sprayed it on their combs and lived to tell the tale?
 

·
Registered
Joined
·
135 Posts
The official names for bee safe products are B 401 or Certan. Not sure if you can get nit in USA but you may be able to get it from Canada!
 

·
Registered
Joined
·
1,660 Posts
Discussion Starter · #7 ·
Thought maybe the small liquid form bottle of BT would be a cheaper alternative to the 1 pound bags of dry BT we have been using that are sold out of date and don't last more than 2 or 3 years at most if purchased with in date . Never thought of the liquid carrier being a petroleum base not sure how bad this would be for the bee's once it gets into the wax comb probably not worth the chance !!
 

·
Registered
Joined
·
1,276 Posts
"Some other strains of Bacillus thuringiensis (BtK) are toxic to bees and humans, so beekeepers must resist the temptation of using other BT products. Do not use the Bacillus thuringiensis subspecies kurstaki , or “BtK”, use the subspecies aizawai,"

Now part of that appears to be grossly incorrect, as BtK is approved for use in treating sweet corn for corn earworm, is even labeled as organic for such use, and is approved to use up to day of harvest, so it's highly unlikely to be toxic to humans.

But have we established that BtK is _not_ toxic to honey bees? Has anyone here sprayed it on their combs and lived to tell the tale?
I have used BtK for several years and never lost a hive to a BtK poisoning. It works very well against wax moths. However, an article from Oregon State University specifically states that the Aizawai strain IS toxic to honeybees. The article can be found here: http://npic.orst.edu/factsheets/btgen.html

As far as finding a liquid version of BtA, I have never seen it or heard that it exists.
 

·
Registered
Joined
·
5,604 Posts
However, an article from Oregon State University specifically states that the Aizawai strain IS toxic to honeybees.
However, the aizawai strain is highly toxic to honeybees. Other strains have minimal toxicity to honeybees.
http://npic.orst.edu/factsheets/btgen.html

This is nonsense, has to be an error. I, along with many other beekeepers, have been using the BTA strain safely for many years with no toxicity to our bees. I would like to see their evidence, or correction, to this statement.



I did notice this sentence in the same section, for what it might be worth.

However, evidence suggests that toxicity to these non-targets may be related to impurities from the production of Bt.
 

·
Registered
Joined
·
1,276 Posts
I don't disagree that it may be wrong but in order to find out for sure, you would need to spray it directly on your bees. Once Bt is used, it starts to break down pretty quickly. My guess is that spraying it on comb and then putting it in storage for several months gives it enough time to break down into harmless byproducts. The rapid rate of decay is why the timing of its use on field crops is so important. I started using BtK because my apiary is fairly small (20 hives) and I could purchase much smaller quantities than BtA is available in. BtK was also much less expensive as I recall.
 

·
Registered
Joined
·
1,669 Posts
Two of those small bottles of liquid Btk is about the same price as a bag of BtA. A bag of BtA take along time to use it up.When spraying it on your combs and they dry the spores remain and when a worm eats it it activates in the gut.It only stays good when mixes for about 24 hours.
 

·
Registered
Joined
·
5,604 Posts
Once Bt is used, it starts to break down pretty quickly. My guess is that spraying it on comb and then putting it in storage for several months gives it enough time to break down into harmless byproducts. The rapid rate of decay is why the timing of its use on field crops is so important.

I don't disagree that it may be wrong but in order to find out for sure, you would need to spray it directly on your bees

Based on some of the literature I've read the main reasons for the rapid breakdown in field application is due to sunlight degradation and wash out from rainfall.

Never thought about the toxicity to bees if sprayed directly on them, good point. I know from experience it's not harmful if the frames are put right back into service after the liquid has dried. Never sprayed it on the bees, don't plan to. :)
 
1 - 12 of 12 Posts
Top