At regular intervals in the past ten years, we have looked at the problems confronting the world’s population of bees.
For these insects are in deep trouble from a variety of serious problems. It is more than four years since I wrote these words in this column: “A seminar, whose organisers recall the quotation attributed to Albert Einstein, ‘If honey bees become extinct, human society will follow in four years,’ has been arranged to alert British bee-keepers to a growing problem in America.”
Well, further news has come from America recently; and I cannot do better than quote the words of Andria Borba, a reporter with FOX40 News on KTXL-TV, Sacramento: “It’s a story with a lot of buzz and a big ole’ stinger. Researchers at San Francisco State University say the reason bees have been disappearing is because of little critters called Apocephalus borealis. The smaller-than-flea-sized pests hitch a ride on bees and release a toxin that basically turns the honey makers into zombies. ‘They’re very small … probably about flea sized … mites that pretty much go on the bees when the bees pollinate the flowers,’ says Serg Borchilo of Sacramento Beekeeping Supply. ‘They have plenty of honey, plenty of pollen, plenty of brood and then all of a sudden the whole colony just leaves the hive and nobody knows why.’”
Apocephalus borealis is not a new arrival. As far back as 1926, Charles T. Brues reported, in an article from the Entomological Laboratory of the Bussey Institution at Harvard University, on a new species of Apocephalus, a genus known to develop as a parasite of ants. And the recent news from the United States is not good news for bees, for Apocephalus borealis might be said to have spread its wings in the past 85 years and is now recognised as a parasite of bumblebees, honey bees and paper wasps. In most of the US, Apocephalus borealis is primarily associated with bumblebees, and that is bad enough news for us all. But in California and South Dakota, evidence has emerged linking the parasites with honey bees as well. Female flies lay their eggs in the bees, and as the larvae develop they attack the bee’s brain and cause the bee to become disoriented, fly at night and exhibit other unusual behaviour, which eventually results in the death of the bee, while increasing the survival rate and spread of the parasites. Nasty.
Bees are being threatened by Varroa mite; they are under attack from pesticides used in farming and in horticulture that, while intended to deal with problem bugs in crops and flowers, are harmful to bees; there are suggestions of new viral and fungal infections to which bees are prone; and now comes news of the perils presented by the parasitical mite Apocephalus borealis. Bees have been regarded as beneficial insects for millennia; we have known for centuries that bees are essential for the well-being of the plant world; now, bees are facing very real threats to their survival. So let’s do what we can in our gardens to help bees by choosing pesticides whose effect on beneficial insects is more limited. You’d expect a chemical which is “hazardous to bees” to be a bit less lethal than a chemical which is “extremely dangerous to bees”. And you would be correct …. although we must never forget that “hazardous to bees” still means just that and means that other instructions must be followed, instructions like “Spray only in calm conditions”, “Spray only affected plants” and “Use only as directed”, which is usually an injunction to dilute the chemical concentrate properly and then to apply only as much as is necessary, never spraying so much that the pesticide is dripping from the leaves. 2012 would be a really good year to be nice to bees.
Sandy Simpson, Polmont Horticultural Society