Magnets, magnetic field fluctuations and geomagnetic disturbances impair the homing ability of honey bees (Apis mellifera)

Abstract

Adult honey bees possess a magnetoreception sense similar to other animals such as birds, fish, whales, dolphins, insects, and microbes. Organisms use this sense for orientation purposes during migrations and traveling long distances. The sudden loss and disappearance of honey bees from a hive or apiary has been plaguing beekeepers for more than a century. This age-old disorder predates virtually all herbicides and pesticides, many diseases or pests and honey bee management protocols. To investigate possible involvement of a magnetoreception disorder (MRD) with loss of forager homing abilities: A. magnetized wires were glued to their abdomens; B. foragers were exposed to artificially induced fluctuating magnetic fields; and C. untreated foragers' return rates were monitored during naturally occurring disturbances to Earth's magnetosphere. Treated and untreated foragers were released at varying distances from their hives and their return rates were monitored. Significant differences in their return rates indicated that interactions existed between forager losses and exposure to both static and oscillating magnetic fields, as well as during fluctuations in the Earth's magnetosphere. In addition, D. decreases in untreated forager return rates also correlated with increasing intensity of extraterrestrial protons that entered Earth's atmosphere. Finally, winter colony losses in the northeast USA also correlated with annual geomagnetic storm occurrences. Collectively, these five observations indicate that coronal eruptions on the Sun are involved with interference of a forager's magnetoreception sense here on Earth. How abnormal magnetic fields and fluctuations relate to the epidemiology of honey bee losses is consistent with their behaviour and development.