Nature Guide Journal: Bees | Local News

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Our garden plum tree has bloomed madly, but it’s not abuzz. Petals are starting to drift from the tree in the clouds, but there wasn’t the swarm of bees you’d expect from such an abundance of flowers.

The Oregon Department of Agriculture reports that about 500 species of bees are native to our state, but very few individuals feed on my flowers. I don’t think we will have many plums this year.

Although humans enjoy honey and use the wax, pollen and other products produced by bees, it is on the pollination role of bees that we depend most.

Pollination by animals is essential to the reproductive success of flowering plants. The showy colors, tempting shapes, and alluring scents of flowers—all biologically expensive characteristics—have evolved to entice animals to aid in the sexual reproduction of plants.

Some flowers are pollinator-specific, being particularly attractive to one species or a few related species; some pollinating animals are flower-specific, others are generalists. Whether specialized or generalized, the association of flower and pollinator has evolved over the eons, determining the shape of these animals as well as the shape of the flowers.

Bees are particularly adapted to drinking and using nectar from flowers, as well as collecting and using pollen from flowers. Long (but not too long) specially shaped tongues draw the nectar from the throats of the flowers. Special hairs on the body and legs (called “pollen baskets”) catch the pollen and keep it on board for the return flight.

Although we may think pollen collection is accidental, bees sometimes target pollen as a protein-rich food source for their larvae.

Of the approximately 200,000 species of animals worldwide that pollinate flowers, approximately 40,000 are bees. In North America and Europe, the native European honey bee (Apis mellifera) is widely used in agriculture. Nearly a third of America’s agricultural crops, mostly fruits, vegetables and nuts, depend on bees to fertilize flowers so they produce fruit – most of these insects are commercial bees.

Honey bee populations have declined dramatically in recent decades, with a 50% decline in American honey bees over the past 50 years. Many species of wild bees, including large fuzzy bumblebees, have declined further – with reports of losses of up to 99% of some species in some areas.

According to the USDA, these valuable allies appear to be overcome by a variety of difficult challenges.

Several types of introduced mites infest honeybees and native bees. Varroa mites, found on honey bees worldwide, pose a very serious threat. In addition to sucking the blood of adult bees, parasitic mites feed on the larvae and pupae of bees. Bees that feed on Varroa mites as larvae or pupae may have deformed or missing wings or legs, and the parasites weaken the bees and make them more susceptible to viruses and other diseases. Varroa mites are native to Asia and North American and European bees have little resistance to them.

The invasion of Africanized bees also weighs as being able to contribute to the decline of bees. A hybrid species between European and African honey bees, Africanized honey bees are more aggressive than honey or native bees and can displace them.

Habitat loss and fragmentation, as well as climate change, are also detrimental, forcing bees to work harder to survive.

Pollution also takes a heavy toll. Pesticides applied to control insect pests often kill allied insects as well; even electromagnetic radiation, such as that from cell phones, can disrupt the navigational systems bees use to find their way back to their hives.

Several years ago I hung a birdhouse in one of our apple trees – well, I wanted it to be a birdhouse. Instead of a bird’s nest, we got a honeycomb. Big dark bees came in and out all summer.

At the end of the season, I opened the box to find it irregularly wrapped with a dark waxy material that smelled faintly of honey and was riddled with tunnels. Nothing else. In a happy twist, the box had been the home of an unsocial native bee – possibly a mason bee.

In addition to identifying and reducing threats specific to commercial bees, some people are turning to native orchard mason bees to pollinate crops. Although they do not produce commercial honey, mason bees are also less likely to sting.

Want to help our native bees?

Limiting pesticides and herbicides through more holistic practices is key to protecting our insect allies. Planting a variety of flowering plants, especially native ones, and letting the “weeds” bloom for as long as possible will provide food for bees and other pollinators, helping them while they help you. Providing suitable nesting habitat, such as leaving neglected corners in the garden and providing wooden “bee houses”, will also support a variety of bees.

Scattering a mix of native wildflower seeds on an untended slope and adding a new bee house are on my spring gardening list. Maybe I’ll have more plums next year.

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