A test of the “drench” method of nosema treatment
In previous articles in this journal, I’ve summarized what we know about Nosema ceranae, its pathogenicity, detection, and treatment. I wondered whether N. ceranae would prove to be as virulent in North America as it appeared to be in Spain. There were also a number of unanswered questions as to the efficacy of treatments and the best ways to apply them. In this article I will report the results of a small field trial of “drench” treatments.
Introduction
Nosema ceranae is of great concern to the many beekeepers who have discovered that their bees are infected. It is indeed widespread, although I have sampled a number of operations in which it is virtually undetectable. Unfortunately, the standard treatment of fumagillin dissolved in heavy syrup has not always proved to be effective. In a trial that I ran last winter of several different ways of applying fumagillin, plus some alternative treatments (in prep), I was surprised to find that no treatment appeared to result in “clean” bees in the spring.
