VIEW ARTICLE

Vector Relations

Honeybee Foraging Behavior, In-Hive Survival of Infectious, Pollen-Borne Blueberry Leaf Mottle Virus and Transmission of the Virus in Highbush Blueberry. W. Boylan- Pett, Department of Entomology, Michigan State University, East Lansing, 48824; D. C. Ramsdell(2), R. A. Hoopingarner(3), and J. F. Hancock(4). (2)(4)Botany and Plant Pathology and Horticulture Departments, respectively, Michigan State University, East Lansing, 48824; (3)Department of Entomology, Michigan State University, East Lansing, 48824. Phytopathology 81:1407-1412. Accepted for publication 9 July 1991. Copyright 1991 The American Phytopathological Society. DOI: 10.1094/Phyto-81-1407.

Factors associated with honeybees that facilitate the spread of pollen-borne blueberry leaf mottle nepovirus (BBLMV) to highbush blueberries were examined. These factors included the longevity of infectious BBLMV in the honeybee colony and in-hive pollen transfer within and between colonies. Blueberry leaf mottle virus remained infectious for at least 10 days within colonies of the honeybee, which is the primary pollinator. Flowering blueberry plants were caged for various periods with colonies of honeybees derived from a blueberry farm where a high percentage of bushes were infected by BBLMV. Twelve of 84 plants later tested positive for BBLMV by enzyme-linked immunosorbent assay. Counts of pollen grains washed from “house bees” (bees that never left the colony) resulted in an average of 5,149 pollen grains per bee, indicating that in-hive pollen-virus transfer occurs and can be a source of spread of virus-contaminated pollen within a colony. Evidence of pollen transfer between colonies and to a lesser extent between apiaries was also documented by observing the drifting (wandering far away from the bee’s hive and/or visiting other hives) behavior of honeybees. Only 42.6% of the total foragers of a colony originated from their own colony and 2.4% of them were from colonies located 600 m apart. This drifting phenomenon could contribute to the maximum spread of BBLMV by bee-to-bee contact and multiple colony visits.