For the past two years, since I bought BT through Zulu, I've been making it a practice to spray my frames with BT after I extract their honey. To me, it looks like the practice is working. As I come across frames that haven't been sprayed (primarily, from the brood nest) I can find wax moth damages, whereas the frames used for honey have been almost totally free of damage,
One hive that died out on me showed the difference very clearly, where the unsprayed brood box frames, unprotected by the absence of bees, were moth eaten, while the upper frames from the honey supers were pretty much untouched.
I did, however, seem to notice a difference in the susceptibility of the lesser wax moth, as compared to the greater wax moths. The lesser wax moths seemed to be less sensitive to BT and were quite numerous in some places.
My apologies for being a bit vague about the description of the differences, but, in the process of rushing through the hives, I didn't make any written notes that could testify numerically to my observations.
Has any one else noticed a diferrence in the control that BT gives to the two different species of wax moths?
