Something In The Air

Isoamyl Acetate, Or C7H14O2 To Its Friends

Chilly, overcast days are not ideal for putting bee-feed on a hive which has weighed in a bit light. But needs as needs must – so a gentle re-arranging of the crownboard to place a slab of fondant on top of a hive of bees which I won’t be seeing again until after Christmas was a necessity. Now, in this season of goodwill, you’d have thought that the appearance on your roof of a jolly, mature male wearing fancy dress and bearing a gift would be construed as a welcome event. But the bees in Iken Hive were not impressed by my Santa Claus impersonation: rowdy and impatient, they were determined to end my intrusion into their roof-space.

They expressed themselves in two ways. In the first instance, a dozen of them flew hard at my white bee-suit, pinging off my veil. I got the message. In the second place, there was pervasive odour, rising from the bees, as they skeetered out of the small, uncovered gap in the crownboard. Normally, the beekeeper is greeted by a mellow aroma of warmed wax, seasoned with a twist of propolis and a waft of honey. This smell was harsh, like nail-varnish, with a cloying, figgy top-note (variously described by others as pear-drops or banana). For those unaccustomed to the odour of nail-varnish, imagine instead a niff of stale furniture lacquer, or a snooterful of drying boat varnish. That is the odour of isoamyl acetate, or C7H14O2 to its friends, which is the bees’ alarm pheromone. For the bees, with a sense of smell far more finely tuned than our own, this scent can turn dainty demoiselles into a flash-mob of feisty amazons in seconds flat.

No surprise to learn that isoamyl acetate is released in quantity when a bee uses its sting. This has the effect of a marking the target zone with a pheromone beacon on which other bees can concentrate their attack. Believe me, if you are stung while working a bee-hive, other bees will rapidly converge to the site of the sting and add their own barbed contribution, unless you can pump your smoker to lay down a smoke-screen to mask the chemical war-cry.

When I can sniff of isoamyl acetate rising from a hive, I know for sure that I have outstayed my welcome. Ideally, as was the case on this occasion, the job in hand is swift and simple: the hive was closed up in a jiffy and settled right down. There are times, however, when my exit strategy is complicated and slow (such as putting a disassembled hive back together following an inspection). In that case, amidst a chain-saw cloud of braveheart bees and puffs of isoamyl acetate, all beekeeping joy is forfeit, and it is a matter of cold efficiency to beat a retreat under cover of smoke, until the hive is restored to completeness.

As a beekeeper, my sense of smell is an important tool in the management of my hives. And it’s surely no coincidence that my surname, spelt backwards, is: “Nosbig“.