For those less fortunate, there are wild insects that work as pollinators. We can attract them to our gardens with plants such as willows and clovers, and even persuade them to come and live there. The best news is that some of them are better pollinators than honey bees, and most of them are gentle and unlikely to sting. In addition to these solitary bees (most do not form colonies), other pollinators include bats, hummingbirds, beetles, butterflies, moths, wasps, and flies.

 

Many mason bees (Osmia spp.) are ideal garden pollinators. Provide them with a nest – a block of wood with lots of 5/16-inch holes, 3 to 6 inches deep, bored in it – hang it in the right place, and a female mason bee will probably lay her eggs there. A popular member of this genus, the orchard mason bee, is a shiny blue-black, and will pollinate many tree fruits and other crops. They are efficient: about 500 mason bees do the same job as 100,000 honey bees. One imported species of mason bee specializes in blueberry pollination. Mason bees are not aggressive.

 

Bumblebees are social insects, but their underground colonies rarely contain more than 500 bees. They will sting only if directly threatened. Many bumblebee colonies are kept in commercial greenhouses and coexist easily with human workers. Outdoors, bumblebees work harder than honey bees, and will fly in cooler temperatures than honey bees will tolerate. They are great to have in a garden, since they pollinate tomatoes, eggplants, peppers, melons, raspberries, blackberries, strawberries, blueberries, and cranberries. They are the only pollinator of potatoes. To attract them, grow red clover – they love it!

 

Leafcutter bees (Megachile spp.) are small, gentle, solitary, and gray. Like mason bees, leafcutters are efficient, with 150 doing as much work as 3,000 honey bees. In the wild they nest in hollow plant stems or holes made by other insects, but they are happy to nest in wood blocks with deep ¼-inch drilled holes, or even bundles of plastic drinking straws glued into a metal can.

 

Some wasps are good pollinators, including the Sphecidae family of thread-waisted wasps that includes digger wasps and mud daubers. Flies in the Diptera family, the hoverflies and syrphid flies, are great natural enemies of aphids and effective pollinators.

 

There is a lot of wonderful information about solitary bees, including which crops attract them and sources of nesting blocks and other supplies, at the National Sustainable Agriculture Information Service website, http://www.attra.org/attra-pub/nativebee.html

 

(This article first appeared in Horticulture magazine)