As the sources of this BT seem to have dried up, I have been in research mode for the last few months, with calls into suppliers etc.
Finally the Local Rep and I had some good calls and have finally found a local source.... and picked up my supply this morning at a greatly reduced price too.... this is of course for use on my Cabbage patch
....but I was extremely interested during my research to find that BT susp aizawai is listed by the EPA as Highly Toxic to Honey Bees....
this was a huge eye opener , so I had to get to the bottom of this.
http://www.epa.gov/oppsrrd1/REDs/0247.pdf page 20 Table 4 last paragraph
154-24 Honey bee MRID 419748-08 Highly toxic; LE = 15 ppm
so I looked up the MRID through various sources and found the original assessment document from 1991
http://www.epa.gov/opp00001/chem_search/cleared_reviews/csr_PC-006403_24-Mar-92_008.pdf..... and on page 2 found that they fed a 1:1 mix with sugar water over 11 days and at the highest dose 1000ppm - mortality was 6.7 days. THUS: It took bees 6 days of continuous feeding to be killed by BT at a HUGE dose as well
The researcher on page 4 comes to the conclusion that the dose far exceeds any normal field situation and Bees would not be affected by normal use, and despite the normal method of spraying fields about once a week the exposure would be minimal. He also surmised that Bee Larvae were most likely to be exposed via Pollen from sprayed fields (but no study was done on this).
Simple interpolation by me, says that the single low dose spray we use has limited to no effect - and this is borne out by the millions of frames of drawn comb that have been sprayed by beekeepers to date using Certan, Agree.WG, Xentari etc , with no effects to their bees, but offering solid protection against wax moth. My own 3 year experience has shown tremendous success agaisnt wax moth in stored boxes
It may be this document in the EPA files from 23 years ago , that has prevented BT from being released in the USA for Bee Keepers to get the benefit.
