How to be a guardian of pollinators

Last week’s issue covered the critical role pollinators play in food production and why the decline of pollinators should be getting everyone’s attention. This week, we’re exploring how individuals can help encourage and protect pollinating critters.

Boulder County Colorado State University Horticulture Extension agent Deryn Davidson’s days are centered on disseminating information and taking action on behalf of pollinators.

“One of the biggest issues is habitat loss,” Davidson said. “Our world is becoming more urbanized, at a rapid pace, and as of 2008 or 2009 the global population tipped from being more rural to being more urban for the first time ever.”

Creating places for bees and other pollinators, even just a little here and there, can make a huge difference in their survival and population growth.

Longmont’s CSU’s Extension office on the Boulder County Fairgrounds has a public demonstration garden for watching pollinators in action and learning how to create a similar environment.

Creating a home sweet home for pollinators

Food -

· Replace swaths of lawn with pollinator attracting flowers. Once established, you’ll also save money on water.

· Give pollinators a smorgasbord by mixing flower varieties. Each type of pollen contains different proteins and minerals, and a variety of shapes and sizes of flowers will attract diverse species.

· Native flowering species create higher quality habitats.

· Plant with seasonal longevity in mind. Early, mid, and late season bloomers are pretty for onlookers, and give pollinators a home base.

· Buy organic plants and seeds to avoid chemicals which can adversely affect pollinators.

Water - Run sprinklers, keep bird baths freshened up, and use shallow dishes of water with rocks for landing pads.

Shelter - A perfect yard is not friendly to bees because most bees like to burrow into protected ground and wood. Leave mower clippings on the ground, pile a little wood in the corner of the yard, and don’t toss plant and tree trimmings – let them sit on the ground.

Note: While it’s justifiable to be concerned if you or a loved one are allergic to bee stings, Davidson said, “On the whole, when native bees are out foraging, they are not in defense mode. For the most part, they want to mind their own business, collect their nectar and get back to their hive.”

Avoid the use of pesticides. All too often they’re toxic to beneficial bugs, which have a lower tolerance level than the targeted pests. Those chemicals also run off into our creek system where it affects aquatic insects causing a weakening and decline in mayflies and caddisflies – the food for amphibians, fish, and birds.

Invite biodiversity into your life and realize that permitting a little damage to plants means you’re supporting food for the entire base of our food chain.

“It’s really important for people to accept and get excited by insects in their yards,” City of Boulder Integrated Pest Management Coordinator, Rella Abernathy said. “A lot of people don’t like any kinds of insects in their yards, so if they see aphids the first thing they do is grab a bottle, whereas there are plenty of natural predators like lacewings, lady bugs and tiny parasitoid wasps that will control them for you. Don’t concern yourself over little cut-out circles on rose leaves. You most likely have leafcutting bees who are building a nest for their young and caterpillars turn into moths and butterflies and are food for birds”

To support food grown with ecological methods, buy produce grown by local and organic food growers.

No yard or want to do even more? Volunteer for Boulder County and the city of Boulder pollinator projects (see the accompanying side bar.)

Pollinator houses

Bee boxes are intended for native bees, which unlike honey bees, don’t work in a beehive colony. Working in solitary, a female bee deposits a glob of collected nectar, lays an egg on top, and then seals it off. The bee will do this many times within each chamber. Over the winter, larvae develop and eat the provisions left for them, becoming the next generation of bees.

As a University of Colorado Boulder postdoctoral research associate in the Department of Ecology and Evolutionary Biology, Dr. Adrian Carper is one of the county’s go-to experts when it comes to pollinators. Carper has helpful and cautionary advice regarding pollinator houses such as those that mysteriously appeared along Hidden Star Trail in Niwot.

“The design is OK,” Carper said. “It uses bamboo or routed wood cavities that are 3/8 inches in diameter. While a lot of bee species can use that size, there are a few issues with it and, of more concern, their placement in natural areas. Firstly, our cavity-nesting bees are tremendously diverse, with over 300 species in the state, and they vary greatly in size. Some need very tiny cavities, down to 1/8 or even 1/16 of an inch. Others are large and can nest in cavities as big as 1/2 inch, so only providing one size can kind of skew bee communities to dominant species. Providing a diversity of sizes would be better.”

Carper said, the non-native alfalfa leafcutter bee that’s become very common in this area, will take over houses with just 3/8 inch cavities and then drive out native bees.

“I applaud concerned citizens for their passion for bees and bee conservation,“ Carper said, “but would caution against installing such nest blocks in natural areas. The biggest concern is that bee blocks need to be consistently monitored throughout the year to be effective. If blocks aren't regularly checked, wind, wildlife or water could kill the entire population within them. Plus, those sandwiched boards would just fall apart and kill all the bees inside them. Bee blocks are much more likely to be monitored and taken care of in your backyard than hidden in a natural area.”

But creating artificial habitats should be a last resort, Carper said. Providing natural native bee habitats such as woody debris is more sustainable, effective, and promotes species diversity.