Development of the Mite, Varroa jacobsoni Oud., in the Honeybee, Apis mellifera L., in Michigan, USA, and Comparison of Diagnostic Methods for Detection of the Mites PDF

Keywords

Honeybee, Varroa jacobsoni, mites, Michigan, Apis mellifera L., sticky board method

Abstract

The study was carried out with fifteen newly established packages of honeybees that were divided into three groups. Each group was inoculated with 5, 10, and 25 Varroa mites as an initial inoculum, respectively. The groups were widely separated from each other to reduce drifting between treatments. The development of the mite infestation was monitored every other week from May until October, 1994. Estimation of the different mite populations was based on a 72-hour mite downfall on a wire-protected sticky board, and a sample of 100 adult bees, plus 100 worker and 100 drone pupae. The colony population of adult bees and brood cells was estimated at each sample period as well. Over the period of one summer, the mite population increased 81, 188, and 193- fold for the groups that were infected with 5, 10 and 25 mites, respectively. Based on 72-hr. mite downfall, the population estimates were 2,032, 1,880 and 968 mites for the groups that started with 25, 10, and 5 mites, respectively. The estimate of the number of mites from the adult bee population was larger than the estimate obtained from sticky boards. However, variation in mite populations between the colonies was large. The sticky board method was better than adult bees and brood samples for the initial detection of mite populations at low infestation levels.