> Chiesa (1991) was able to control V. jacobsoni in honey bee colonies with > thymol without noticeable damage to the colonies at temperatures ranging > from 5 to 9 C (41-48 F). However, Gal et al. (1992) found thymol > applications deleterious to bees when temperatures reached 27-28 C (80-82 > F). I have used thymol crystals at 30C without problems (but not often - 30C is unusual here), but it should be remembered that I have fully open mesh floors. With lower temperatures I find that thymol works well in colonies with plenty of brood, but is much slower to evaporate (or deliquesce) in colonies with little brood. This is very noticeable with our bees (A.m.m.) as poor weather in July can cause queens to go off lay temporarily. We seem to have no problems using thymol on colonies returning from the heather moors in September when the weather can be much cooler - these colonies normally return with large areas of brood after the stimulation of working heather. So in my view it is the warmth from the brood that makes all the difference. Have researchers considered the varying effects of mesh floors, amount of brood and the sub-species of bee? Best wishes Peter *********************************************** The BEE-L mailing list is powered by L-Soft's renowned LISTSERV(R) list management software. For more information, go to: http://www.lsoft.com/LISTSERV-powered.html Guidelines for posting to BEE-L can be found at: http://honeybeeworld.com/bee-l/guidelines.htm