Massive die-off linked to parasites, pesticidesBy Owain Johnston-BarnesThe Bermuda bee population has suffered a massive die-off, with some beekeepers losing 70 percent of their colonies.The decline is attributed to several factors, including two parasites recorded on the Island in a recent study and the potential impact of some pesticides.Over the last decade bee populations around the world have been devastated by what has been called ‘colony collapse disorder’, believed to be caused by a combination of parasites and pesticides. In addition to reducing honey production, the die-offs can severely impact crops which require bees for pollination.A spokeswoman for the Ministry of Environment said that inspections of several bee yards on the Island, also known as apiaries, have confirmed “substantial losses”.However, the spokeswoman noted several bee swarms have been reported in recent weeks, suggesting the population may be rebounding.Samples taken from colonies around the Island have revealed two species of parasites — Nosema ceranea and varroa mites. While harmful to bees, the ailments do not affect humans, meaning there in no concern about consuming Bermuda honey.“Since last fall, the Department has been concerned about an increase in signs that often indicate a Nosema infection (bees crawling on the ground, lethargy, lack of honey collection) and the observation of a colony with numerous bees displaying the characteristics of Deformed Wing Virus,” the spokeswoman said.“The occurrence of these two indicators, in conjunction with the dramatic colony die-offs and poor honey collection, suggest that the bees are suffering from a depressed immune system which would allow the expression of the virus symptoms and Nosema levels to increase within colonies.“Research has indicated that any stressor that the bees encounter, such as Nosema, varroa, viruses or exposure to some pesticides may not itself cause the bees to die, but when several stressors are present they can have a synergistic effect, resulting in colony collapse.”While the Department has not linked local pesticide use to the declining bee populations on the Island, Jamie Bacon of the Bermuda Zoological Society has carried out research showing severe pesticide effects on other species in Bermuda.Studies done elsewhere in the world have linked neonicotinoid insecticides and other pesticides to a number of negative effects in honey bee populations, including immune system suppression, altered feeding and communication behaviours, spatial orientation and navigation.Director of Environmental Protection Frederick Ming said: “There is no reason to believe that these same high-risk pesticides will behave any differently in Bermuda than in other parts of the world. We would be wise to adopt the precautionary principle and take appropriate action to confront the threat.“Because farmers do care about the environment and depend on bees to pollinate certain crops (pumpkins, squash and others) we are optimistic about being able to confront the problem together.”Currently, the Department is in discussion with a bee researcher from the US who is interested in assisting us with a sustainable solution to varroa control. A spokesman said he is proposing the introduction of a naturally occurring ‘varroa detection and removal’ trait which will help control the parasite.Farmer Carlos Amaral said yesterday that he was fortunate in that he has not seen his crops impacted by a decline in bees thus far.“There are other pollinators out there and from what I have seen the hoverflies have picked up the slack,” he said. “Maybe I’m just lucky. My zucchinis have come in nicely, the melons are holding. A lot of my crops are wind pollinated.”He blamed the die-off on the accidental introduction of the varroa mite rather than pesticides, saying that the bee population on the Island was holding strong until the mites appeared.“I think it shows just how much they have impacted the Island,” he said. “The track record of the bee population on the Island was stellar. Once we had that one vector introduced, we saw the decline.”l If the public discover bee swarms, they are asked to report them to either a beekeeper or the Department of Environmental Protection’s Plant Protection Lab at 239-2322.The swarms should not be sprayed as they are a valuable, threatened resource.