The International Pollinators Initiative identifies the need to
monitor changes in the diversity and abundance of pollinators and to train
specialists to keep inventories. Public awareness is a key focus as
gardeners and farmers play a direct role in pollinator conservation.
Insect pollination is required for nearly all fruits and
vegetables, including annual crops like tomatoes, peppers and strawberries, and
tree fruits like apples and peaches. Crops like melons, pumpkins and
cucumbers have separate male and female flowers, and would bear no fruit
at all without insect pollinators. The value of pollination services for
crops, like mustard, canola, alfalfa and fruits and vegetables has been
conservatively estimated at $1.2 billion per year in Canada. Therefore,
protecting honeybees and other important pollinators is essential to
farmers' livelihood.
Threats to pollination
There are several factors contributing to the decrease in
pollination. Habitat destruction, including nesting and mating sites, and
alternative forage, is the main issue in the decline of wild pollinators. A
diverse floral habitat provides the most abundant alternative forage.
Flower-rich field borders, where non-crop forage plants are not treated as
weeds, encourage a diversity of pollinators. On the other hand,
clearing field borders, fence lines and hedge rows destroys habitat and
eliminates alternative food sources. Prairie grasslands and natural pasture
can support native pollinators if not over-grazed or brought into annual
crop production. Also, cutting hay too early before bloom deprives
native pollinators of their feed.
Another serious threat to pollination is pesticide use which has
doubled in North America since 1960. Although many insecticides are more
effective at killing beneficial insects than pests, a growing number of
people spray pesticides on their lawns and gardens. Even at low levels,
pesticides affect longevity, memory, navigation, and foraging abilities
of the honeybee. The use of herbicides eliminates the natural forage
that wild pollinators need before and after crops are in bloom.
In addition, there are two predators attacking honeybees. The
tracheal mite from South America attacks the bee's windpipe and eventually
suffocates its victim. The varroa mite from Asia attaches itself
externally and feeds on fluids from the host bee. These small relatives of the
spider are responsible for the destruction of 30 to 50 per cent of
beehives in Eastern Canada.
About the honeybee
There are 1000 wild species of bees in Canada. The domestic
European honeybee remains the most important insect pollinator as it collects
both pollen and nectar. A honeybee colony has one queen who produces up
to 2000 eggs a day. She lives among hundreds of male bees called
drones and more than 80 000 imperfect female bees. Despite its name,
the honeybee is much more valuable as a pollinator than a honey producer.
It has a long tongue, a hairy pollen-collecting coat and the ability to
warm itself. A honeybee will visit many flowers over its lifetime.
Despite being too small to trip the pollinating mechanism of some clovers
and field beans, it is heavily relied upon because of fluctuating wild
bee populations.
The role of farmers
Farmers can help conserve pollinators and protect their crops in
several ways. To begin with, they must appreciate the important role
honeybees play in pollination. For example, they should avoid spraying
during crop bloom because this is when pollinators are most likely to visit.
Farmers should consider planting different crops in smaller fields to
promote pollinator abundance and diversity. Also, treating non-crop
plants like thistles, milkweed, and chicory along fence rows and field
borders as bee forage rather than weeds and setting aside herbicide-free
meadows will provide alternate forage for bee populations.
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