Beesource Beekeeping Forums banner
1 - 20 of 57 Posts

·
Registered
Joined
·
356 Posts
Discussion Starter · #1 ·
I am looking for information on treating old drawn comb with BT to avoid wax moth issues,.,.

where can I get it?? what type of BT is ok to use on the comb? what concentrations do I use? any help is appreciated
 

·
Registered
Joined
·
356 Posts
Discussion Starter · #5 ·
Thanks for all the help,, now all I need is the recipe for the right concentration?

Buzz- unfortunately it does not freeze that well down here in the Carolinas
 

·
Registered
Joined
·
27 Posts
I freeze for SHB, then spray Xentari. The stuff works as advertised.

I use a Tablespoon for one gallon, it's a bit more than the label says, but convenient to measure. A gallon will easily spray 100 deep frames. If you are a hobbyist, one bag will last a lifetime.

It's also great for strawberries and other garden worm targets, completely organic...
 

·
Registered
Joined
·
3,085 Posts
The variety of Bt for use against wax moths is Bt v. aizawai. One online source is:
http://www.hidhut.com/xentari-p-31.html
WHOOOOAAAA! Granted, I'm a noo-bee, but this is a topic I was looking up a couple of weeks back. The only "insecticide" we use is mosquito dunks in rain barrels, and I was looking up if it is safe for bees. The strain used in dunks should be OK. But B. t. aizawai, that one scares me. I believe that's the one that kills bees.

Here are my notes:

From http://www.epa.gov/oppsrrd1/REDs/0247.pdf
This is ref 3 of another report that says one subspecies of Bt is toxic to bees, but not which one. From this, mosquito dunks should be OK. Tracking down the specifics:

http://npic.orst.edu/factsheets/BTgen.pdf

Table 2 B. thuringiensis subspecies israelensis
GUIDELINE MRID RESULT
154-23 green lace-wing 418427-08 16-day LC > 1.5 x 10 cfu/g diet; 16-day NOEL = 2.5 x 10
larvae cfu/g
50
8 4
parasitic 418427-09 30-day LC > 7.9 x 10 cfu/g diet
hymenoptera
50
7
predaceous 418427-10 9-day LC > 1.8 x 10 cfu/g diet
coleopteran
50
8
154-24 honey bee 418427-11 5-day LC50 > 7.0 x 10 cfu/g diet
7

(i.e. B. thuringiensis subspecies israelensis has little effect on honeybees. This is the strain used in mosquito dunks, and it targets mosquitos and certain flies.)


Table 4 B. thuringiensis subspecies aizawai
GUIDELINE MRID RESULT
154-23 green lace-wing 419943-21 NOEL = 10,000 ppm
larvae
422453-01 Toxic to larvae at 10x field rate
parasitic 419943-19 NOEL = 100 ppm
hymenoptera
predatory mite 419748-09 1x field rate resulted in 24% corrected mortality
predaceous 419943-20 NOEL = 10,000 ppm
coleoptera
429421-01 NOEL = 1566 ppm
154-24 Honey bee 419748-08 Highly toxic; LE50 = 15 ppm

With the exceptions of MRIDs 414434-09 and 422453-01, the nontarget
insect B. thuringiensis subspecies kurstaki, B. thuringiensis subspecies israelensis,
B. thuringiensis subspecies tenebrionis (CryIIIA) and B. thuringiensis subspecies
21, aizawai studies show little to no toxicity or pathogenicity in the tested neuroptera,
hymenoptera, coleoptera, arthropod and annelida group indicator species. The
above honey bee data indicate a high degree of toxicity for B. thuringiensis
subspecies aizawai and minimal toxicity for B. thuringiensis subspecies kurstaki,
B. thuringiensis subspecies israelensis and B. thuringiensis subspecies tenebrionis.


With the exception of honey bee and earthworm testing, all of the nontarget
insect studies listed above were graded as supplemental. However, since the
Agency currently waives the requirement for nontarget insect data (but not
honeybee testing) for registration, no additional data are required. These data are
routinely waived because Bacillus thuringiensis does not cause epizooatics in the
field; it functions by a toxic mode-of-action.
(This strain is effective against butterflies and moths, so might be used in gypsy moth control. It appears to have a secondary toxin, deadly to many other organisms including bees, so beware of this one if gypsy moth spraying is scheduled.)
 

·
Super Moderator
Joined
·
11,224 Posts
The only "insecticide" we use is mosquito dunks in rain barrels, and I was looking up if it is safe for bees. The strain used in dunks should be OK. But B. aizawai, that one scares me. I believe that's the one that kills bees.
The Bt variety that targets mosquito larva is israelensis.

The EPA document you linked is 100+ pages. Perhaps you could identify where you believe that document says that v. aizawai is a problem for honeybees?

In the meantime here is a less complicated Bt reference from Colorado State University:
The specific activity of Bt generally is considered highly beneficial. Unlike most insecticides, Bt insecticides do not have a broad spectrum of activity, so they do not kill beneficial insects. This includes the natural enemies of insects (predators and parasites), as well as beneficial pollinators, such as honeybees. Therefore, Bt integrates well with other natural controls. For example, in Colorado, Bt to control corn borers in field corn has been stimulated by its ability to often avoid later spider mite problems. Mite outbreaks commonly result following destruction of their natural enemies by less selective treatments.

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

·
Registered
Joined
·
3,085 Posts
Sorry it is so sloppy, but the cut and paste formatting doesn't translate.

I indicate in my notes that the mosquito dunk subspecies is OK ... that is what I was looking up.

Table 4 in that first EPA link is where the bee toxicity is. And yes, I had to plough thru a lot to find it. Very tedious. I've made the specific line bold.

The notes below that suggest that two other subspecies should be effective against moths without serious harm to honeybees. The mosquito dunk kind does not kill moths or bees. I put that in bold as well.
 

·
Super Moderator
Joined
·
11,224 Posts
Perhaps you may wish to revisit Table 4 and its supporting references.

Note from section C.1. of the EPA document (just above where Table 4 is located):
1. Ecological Toxicity Data

The Agency concludes that toxicity and infectivity risks due to delta-endotoxin effects to nontarget avian, freshwater fish, freshwater aquatic invertebrates, estuarine and marine animals, arthropod predators/parasites, [HIGHLIGHT] honey bees, annelids and mammalian wildlife will be minimal to nonexistent [/HIGHLIGHT] at the label use rates of registered B. thuringiensis active ingredients.

http://www.epa.gov/oppsrrd1/REDs/0247.pdf
 

·
Registered
Joined
·
3,085 Posts
I read that as the effects when used generally IN THE ENVIRONMENT at recommended doses. I don't read that as using on comb in the hive.

It does appear, though, that the document contains more than one Table 4, with no apparent change in section number that I can see. Check page 20.

With two other subspecies to choose from, why use the one with that warning about honeybee toxicity?
 

·
Super Moderator
Joined
·
11,224 Posts
The For Sale thread where Sundance offered Bt v. aizawai has been deleted.


> With two other subspecies to choose from, why use the one ..

You can use whatever variety of Bt you want. But the variety that targets wax moths is aizawai, so other varieties aren't much use on comb.
 

·
Registered
Joined
·
3,085 Posts
All I can say is, Table 4 on page 20. Not my claim ... this is the EPA. Maybe they found a strain that was OK, but I'll take an official government document over an advertising claim. Not that I think the government is always right, but where pesticide safety claims are being made ....

http://www.epa.gov/oppsrrd1/REDs/0247.pdf
 

·
Registered
Joined
·
3,085 Posts
Interesting.

I see no ill effects of using Xentari. This study actually has the bees (Bumblebees) ingesting it in feed:

http://www.ncbi.nlm.nih.gov/pubmed/20024947

I doubt I give them enough to kill them, but if I can keep the mites from killing them, maybe I'll find out..
What I read from that link:

RESULTS:

Exposure of bumblebees dermally or via treated pollen to either of the two Bt formulations at their field recommended rates (0.1%) caused no reduction in survival. However, when applied in the feeding sugar water, aizawai killed all workers at a concentration of 0.1%, but this lethal effect was lost at 0.01%. With respect to reproductive effects, kurstaki was harmless, while aizawai at 0.1% delivered in the feeding sugar water and pollen reduced reproduction by 100 and 31% respectively. Lower doses of 0.01% aizawai in the sugar water showed no more effect. In addition, kurstaki at 0.1% and aizawai at 0.01% in the feeding sugar water did not impair the foraging behaviour, resulting in normal nest colony performance.
 

·
Registered
Joined
·
1,530 Posts
BtA does not go in the food supply. It gets sprayed on the stored comb and prevents a moth infestation. I used it while I was still in Florida (at the recommendation of the local bee inspector, which is how I heard of it in the first place) and it had no ill effects on my bees for all the years I used it. It is a much safer and more benign alternative to the moth chemicals sold by the supply houses.

JMO

Rusty
 
1 - 20 of 57 Posts
Top