World Bee Day....A Little "Bee"hind

World Bee Day happened the other day, May 20, and it caught me off guard. I had never heard of it, and hustled to make some social media posts for the Facebook groups I founded or administer. I will plan a bigger campaign of celebration next year, but for now....

In fairness, World Bee Day has not been in existence very long. The date honors the birthday of Anton Janša of Slovenia, a pioneer of modern beekeeping in the eighteenth century. The United Nations passed a resolution submitted by Slovenia in 2017 to so honor him. While beekeeping in the northern hemisphere applies only to honey bees in the genus Apis, the U.N. has chosen to use World Bee Day as an opportunity to acknowledge all bee species, the vast majority of which are solitary and not managed by human beings.

North American bees range from giant "large carpenter bees" like this one....

Given the plight of pollinators in general, and the threats to apiculture (beekeeping) from mites, pesticides, industrial-scale agriculture, habitat destruction, and climate....anomalies of increasing frequency, it is easy to be pessimistic and sorrowful on World Bee Day. However, there are signs of hope all around us.

....to tiny Perdita mining bees like this one.

More people are taking up apiculture as a hobby, for example. Even better, many homeowners and small-scale farmers are recognizing the importance of native bees and building simple housing for them in the shape of "bee condos." Now a small movement is building to advocate for allowing those bare patches of soil in your lawn and flowerbed to lie fallow. The overwhelming majority of solitary bees in North America nest in burrows they excavate in the ground. Sometimes many females will nest in close proximity, giving the illusion of a "hive" or a swarm. This is not the case, and unless you step on a bee in bare feet or forcibly grab one, it is not going to sting you. Different bee species prefer different textures of soil, from sandy to clayey.

Leafcutter bees, Megachile sp., using "bee block."

Among the many reasons to celebrate World Bee Day this year is the rediscovery of the world's largest bee, Wallace's Giant Resin bee, Megachile pluto, nesting in termite mounds in Indonesia. It is an important reminder that the natural world is resilient, to at least some degree, and that most species can persist even in unfavorable circumstances.

Female cactus bee, Diadasia sp., entering her burrow.

Colorado, where my wife and I live, ranks fifth in bee diversity in the USA, boasting at least 946 species from huge bumble bees to tiny mining bees in the genus Perdita. California (1,651), Arizona (1,182), New Mexico (991), and Utah (979) rank ahead of us. That makes for a lot of bee species that need conservation if we want to continue enjoying wildflowers and eating everything from blueberries to squash to almonds.

We can encourage bees by....

• landscaping with native trees, shrubs, herbs, and flowers.
• Erecting bee blocks as supplementary housing for solitary bees (and wasps) that normally nest in the dead trees we cut down and logs we haul off.
• Become "weed tolerant" of plants that volunteer in our yards, as long as they are not state-listed noxious weeds. Chances are they are native or naturalized wildflowers instead.
• Leave a few bare patches in the lawn (if you still insist on having a lawn) and flowerbeds so that ground-nesting bees have a place to call home.
• Advocate for changes to municipal and HOA codes and rules that currently discourage eco-friendly landscaping.

It goes without saying that eliminating pesticides and other chemicals from your yard and garden will greatly benefit all life, not just on your property but elsewhere, too, as pesticides drift on the wind and flow in runoff from rain and watering.

Female sweat bee, Agapostemon sp., living up to her name.

World Bee Day is behind us this year, but no worries. You can gear up now to celebrate National Pollinator Week next month, June 17-23, 2019. Tell me how you plan(t?) to respect that designated "holiday." Maybe you need to do what I should do, which is call my governor and ask why Colorado is not yet on the map for it....

Cuckoo bee, Nomada sp., leaving (left), small carpenter bee, Ceratina sp., arriving (right).

Wasp Wednesday: Not Wasp?

The beginning student of Hymenoptera (the order of bees, wasps and ants) cannot be blamed for misidentifying some members of the group, especially in the field where close-up and magnified views of the subject are impossible to obtain. The bees of the genus Nomada, for example, are easily mistaken for wasps.

The first time I encountered one of these “cuckoo bees,” I was convinced it was a “beewolf” wasp in the genus Philanthus. After all, there was a picture of Philanthus politus in Howard Evans’ wonderful book Wasp Farm that was a dead ringer for what I saw. Well, black-and-white photos don’t translate too well, and that species of beewolf does not occur in Oregon, where I saw my “wasp.”

There are more than 300 species of Nomada in North America. They are kleptoparasites of other solitary bees, meaning that their larvae feed on the pollen and nectar stored for the larvae of the host species. Members of the genera Andrena and Agapostemon are the common hosts for Nomada. Consequently, cuckoo bees are usually seen in the early spring, when Andrena bees are nesting. Watch for Nomada bees flying low over the ground in sunny openings in woodlands and along forest edges.

Because cuckoo bees exploit the hard work of the host bees, female Nomada have no “pollen baskets,” or dense brushes of pollen-collecting hairs on their bodies. They are quite naked, in fact, which adds to their wasp-like appearance.

Compare the bees in these images with the Cerceris wasps from last week. You may have a hard time telling the difference. I did, too. For a bit I was convinced I had images of a Nomada bee instead of a weevil wasp.

There is some consolation in the fact that our current scientific understanding of the phylogeny of bees and sphecoid wasps shows that the two groups are closely related. Sphecidae, Crabronidae, and all the bee families are now grouped under the superfamily Apoidea. Bees are apparently just wasps that at some point in their collective genetic lineages stopped hunting prey and started gathering pollen and nectar. Feel better now?