BEE IN CONTROL

A queen honeybee exerts a staggering level of control over the behavior of her
subjects. Her secret lies in a substance she secretes called queen mandibular
pheromone. Now scientists at Simon Fraser University in Vancouver possess the
queen's secret as well: They've identified its five major ingredients, and
they're testing the effectiveness of a diluted synthetic spray in increasing the
fruit quality and yield of flowering crops that rely on the honeybee for
pollination.

Chemist Keith N. Slessor and biologist Mark L. Winston report encouraging
results from preliminary tests on pear trees, cranberries, and blueberries. The
chemical, licensed to a company called PheroTech, attracts worker bees, which
gather pollen from flowers.

``Clearly, if we are able to exercise in the farmer's field the kind of
sociochemical control the queen exercises within the colony,'' Slessor says,
``we can dramatically expand the economic value of an already beneficial social
insect.''

Most of the pheromones produced by the queen are known as ``releaser'' compounds
that help bees mate, recognize their nest, and respond to alarms, says Slessor.
But queen mandibular pheromone belongs to a class called ``primer'' pheromones,
and it inhibits the rest of the hive from raising a new queen, much less
crowning her. That message spreads through the nest via workers who line up to
lick the pheromone off the queen in a process that bee people call ``retinue
response.''

The scientists first documented queen mandibular pheromone and the workers'
resulting behavior in the mid 1980s, but pinpointing the pheromone's components
required running some 3,000 bioassays. It turns out that the compound, produced
by the mandibular glands, consists of three forms of decenoic acid and two
aromatic compounds known in chemical short hand as HOB and HVA.

A synthetic version of the pheromone could prove invaluable not only in managed
crop pollination, because it stimulates pollen foraging by worker bees, but also
in ``monitoring and potential control of honeybee diseases,'' Slessor says.