A sequential sampling scheme for detecting infestation levels of tracheal mites (Heterostigmata : Tarsonemidae) in honey bee (Hymenoptera : Apidae) colonies

The introduction of parasitic honey bee mites, the tracheal mite, Acarapis woodi (Rennie) in 1984 and the Varroa mite, Varroa jacobsoni, in 1987, has dramatically increased the winter mortality of honey Lee, Apis mellifera L. , colonies in many areas of the United States. Some beekeepers have minimiz ed their losses by routinely treating their colonies with menthol, currentl y the only Environmental Protection Agency-approved and available chemical for tracheal mite control. Menthol is also expensive and can interfere with honey harvesting. Because of inadequate sampling techniques and a lack of information concerning treatment, this routine treatment strategy has incre ased the possibility that tracheal mites will develop resistance to menthol It is important to establish economic thresholds and treat colonies with m enthol only when treatment is warranted rather than treating all colonies r egardless of infestation level. The use of sequential sampling may reduce t he amount of time and effort expended in examining individual colonies and determining if treatment is necessary. Sequential sampling also allows stat istically based estimates of the percentage of bees in standard Langstroth hives infested with mites while controlling for the possibility of incorrec tly assessing the amount of infestation. On the average, sequential samplin g plans require fewer observations (bees) to reach a decision for specified probabilities of type I and type II errors than are required for fixed sam pling plans, especially when the proportion of infested bees is either very low or very high. We developed a sequential sampling decision plan to allo w the user to choose specific economic injury levels and the probability of making type I and type II errors which can result inconsiderable savings i n time, labor and expense.