# Bacillus thuringiensis (Certan, Xentari) Safety



## Chan Rambo (Mar 3, 2015)

I am having trouble figuring out what strain of BT is in Certan - Xentari is BTA. 

I use BTK to control cabbage worms on my broccoli and other brassicas, and BTI in all my standing water sources to kill mosquito larvae. None have any impact on anything other than the particular type of insect that they like to infect. All forms of BT are simply bacteria that infect the larva of various insects, different strains impact different larvae. I am planning to use BTI in my bee water because I am violently anti-mosquito. I've searched the internet and asked my extension office, and the broad consensus seems to be: none of the currently available strains have any impact on bees at all. The larvae in question has to either eat the leaves or drink the water that has been treated, so the only way to hurt bees with it would be to find a strain that impacts them and then spray it onto bee bread.


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## Chan Rambo (Mar 3, 2015)

Here is some more info on the currently used strains:

http://www.ext.colostate.edu/pubs/insect/05556.html


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## laketrout (Mar 5, 2013)

The problem seems to be finding it , Amazon is out of it most of time whenI look for it .

Looks like this one is avail. http://www.amazon.com/dp/B004CZ1MOM...qmt=b&hvbmt=bb&hvdev=c&ref=pd_sl_5wh6ukdy0u_b

Is this the right one to use for wax moth .


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## Rader Sidetrack (Nov 30, 2011)

Some Bt toxicity info is here: http://pmep.cce.cornell.edu/profiles/extoxnet/24d-captan/bt-ext.html

"Certan" is Bt variety _aizawai_. More info here: http://www.vita-europe.com/products/b401/


Xentari and Certan are both brand names for Bt variety _aizawai_, used to control wax moth larva.


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## snapper1d (Apr 8, 2011)

Chan Rambo said:


> Here is some more info on the currently used strains:
> 
> http://www.ext.colostate.edu/pubs/insect/05556.html


I see Colorado State University say both the aizawi and the kurstaki kill Lepidoptera larvae.I used some Btk once and it killed wax worms also so I guess that why.


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## laketrout (Mar 5, 2013)

Why don't the charts show the xentari strain .


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## Rader Sidetrack (Nov 30, 2011)

Cuz ...


> Xentari and Certan are both [HIGHLIGHT]brand names[/HIGHLIGHT] for Bt variety aizawai ...


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## Phoebee (Jan 29, 2014)

Graham will remember the stink I caused here a year or so back when I recognized aizawai as the Bt subspecies that the EPA had in a report as harmful to bees. Of the four subspecies they named, that was the only one that did significant harm. I was looking up the subspecies used for mosquito control (Bti) ... that one should have next to no effect on honeybees.

But maybe that was just a particular strain, and the strain marketed for wax moth control is not so bad. Plus, you don't put it on the bees, you put it on comb removed from the hives for the season. Bt works by preventing larvae from molting, so if no live organisms get on bee larvae, you would not expect damage.

I had good luck last winter by putting the supers and frames into large plastic bags and filling the bags with CO2 gas. A long exposure to 80% or higher CO2 will kill just about anything that uses oxygen, including all life stages of wax moths. I picked up the trick from a Smithsonian conservator who uses it to kill the various bugs that eat their displays. CO2 is toxic to humans in concentrations as low as 1%, but leaves no residue and is classified as "Generally Recognized As Safe" (GRAS) when used as a pesticide. The frames I fumigated this way last fall seem to be in fine shape.


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## Rader Sidetrack (Nov 30, 2011)

I am _shamed_ to admit that I didn't remember that thread, but here it is ... 

http://www.beesource.com/forums/showthread.php?293389-using-BT-for-wax-moth-control

Keep in mind that the way _most_ beekeepers apply Bt is to spray it on unused comb, not feed it in sugar syrup.


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## Phoebee (Jan 29, 2014)

And all I can add is, follow the directions for use against wax moths. If you were to put it straight into a living hive, don't come crying to me if your larvae die a horrible death, as the EPA data in the report quoted somewhere down in the bowels of that long thread say is the likely outcome.


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## Mike Gillmore (Feb 25, 2006)

Phoebee said:


> Bt works by preventing larvae from molting, so if no live organisms get on bee larvae, you would not expect damage.





> Mode of action
> DiPel and XenTari each have four different insecticidal crystal proteins. Once ingested the toxic proteins disrupt the insect gut causing cessation of feeding within minutes and thus prevent damage to the grapes. In addition, DiPel and XenTari have spores that enter the insect blood and usually kill the insect after 1-3 days.


http://www.valent.com/agriculture/products/xentari/loader.cfm?csModule=security/getfile&pageid=45766




> Bacillus thuringiensis subspecies aizawai that is manufactured specifically for wax moth control in stored comb. The material is formulated to kill young wax moth larvae as they attempt to feed on comb and must be used as a preventive before combs are infested. B401 leaves no residue on comb and it is harmless to bees and humans.* Some other strains of Bacillus thuringiensis are toxic to bees and humans*, so beekeepers must resist the temptation of using other BT products


http://www.clemson.edu/extension/beekeepers/publications/wax_moth_ipm.html


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## Vance G (Jan 6, 2011)

Zentari/aizawa will only harm humans who have a larval life stage. It simply doesn't think people tastes good. I have noted no damage to bees after using treated combs.


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## Phoebee (Jan 29, 2014)

Vance G said:


> Zentari/aizawa will only harm humans who have a larval life stage. It simply doesn't think people tastes good. I have noted no damage to bees after using treated combs.


Yeah, about the worst effect on humans would be an allergy. Bt is one of the things they spray for gypsy moths. Three of the four subspecies are active against butterflys and moths, the fourth to flies and mosquitoes. However, Ba, _Bacillus anthracis_, scares my buddies at Homeland Defense witless.


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## EricConcE (Jan 7, 2014)

Vance G said:


> Zentari/aizawa will only harm humans who have a larval life stage.


 Haha good to know! In the link Rambo posted: "Unlike typical nerve-poison insecticides, Bt acts by producing proteins (delta-endotoxin, the "toxic crystal") that reacts with the cells of the gut lining of susceptible insects. These Bt proteins paralyze the digestive system, and the infected insect stops feeding within hours." Also goes on to say that there is a high margin of safety in humans.


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