- Author: Kathy Keatley Garvey
People are keeping cool--or trying to--in their homes, workplaces or in newly opened community cooling centers.
Can you imagine what it's like for a honey bee colony? The normal brood-nest temperatures should be about 93 to 94 degrees, according to Norm Gary, UC Davis emeritus professor of entomology.
In his book, The Honey Bee Hobbyist: The Care and Keeping of Bees, Gary explains that "bee colonies require small quantities of water--up to around 7 ounces per day--but the water they collect is vital to their survival. During periods of hot weather, bees evaporate tiny droplets of water in the hive to control the internal colony temperature. Maintenance of internal colony humidity is important to developing larvae. In addition, nurse bees use water to reconstitute honey to nectarlike consistency when feeding larvae."
We remember Extension apiculturist Eric Mussen (now emeritus) of the UC Davis Department of Entomology and Nematology, telling beekeeping associations to "always provide fresh water for your bees on your property. Otherwise, they will visit the neighbor's hanging laundry, bird bath, swamp cooler, dog dish, leaky hose connection, etc."
In his book, The Backyard Beekeeper: An Absolute Beginner's Guide to Keeping Bees in Your Yard and Garden, Kim Flottum, then editor of Bee Culture magazine, points out that "A summer colony needs at least a quart (liter) of water every day, and even more when it's warm."
"Water is used to dissolve crystallized honey, to dilute honey when producing larval food, for evaporation cooling during warm weather, and for a cool drink on a hot day," Flottum writes in his book.
Some folks add stepping stones or corks in water fountains, bird baths or ponds to assist the bees in their water-collecting endeavors. Usually, though, bees simply stand at the water's edge.
"Probably the most successful homemade water feeder design," Gary says, "is an inclined board that allows water to trickle down slowly into a catch basin so that it can be recirculated."
- Author: Kathy Keatley Garvey
But have you ever seen the digger bees?
They're out there.
The sand cliffs are the home of the digger bee, a bumble bee mimic known as Anthophora bomboides stanfordiana. This bee builds turrets in the sand cliffs.
Last Thursday we watched several digger bees warm their flight muscles, take flight, and forage on the lupine, wild radish, and seaside daisy. Then we saw the females zipping in and out of their turrets: their cozy castles in the sand.
As the late Robbin Thorp, a global authority on bumble bees and a UC Davis distinguished emeritus professor of entomology, told us several years ago: "The species name indicates that it is a bumble bee mimic. These bees need a source of fresh water nearby. Females suck up water, regurgitate it on the sandstone bank surface, then dig away at the soft mud. They use some of the mud to build entrance turrets, presumably to help them locate their nests within the aggregation of nests."
"The female," Thorp said, "sucks up fresh water from nearby, stores it in her crop (like honey bees store nectar) for transport to the nest. She regurgitates it on the sandstone, and excavates the moistened soil. She carries out the mud and makes the entrance turret with it."
As part of a National Science Foundation grant, community ecologist Rachel Vannette, assistant professor, UC Davis Department of Entomology and Nematology, is teaming with other colleagues, including pollination ecologist Stephen Buchmann, to research these digger bees and their nests.
It's a big beautiful bee world out there.
- Author: Kathy Keatley Garvey
Early scientists figured it was aerodynamically impossible for bumble bees to fly due to their size, weight and shape of their bodies in relation to their total wingspan. And then there were those air resistance issues.
“Antoine Magnan, a French zoologist, in 1934 made some very careful studies of bumble bee flight and came to the conclusion that bumble bees cannot fly at all! Fortunately, the bumble bees never heard this bit of news and so went on flying as usual.”—Ross E. Hutchins, Insects, p. 68 (1968). Magnan's 1934 work, Le Vol des Insectes (vol. 1 of La Locomotion Chez les Animaux).
But bumble bees fly quite well, thank you--and can do so with a heavy load of pollen.
Ever watched the yellow-faced bumble bee, Bombus vosnesenskii, in flight?
We watched B. vosnesenskii foraging on yellow lupine (Lupinus arboreus) last Thursday, June 10 at the Doran Regional Park, Bodega Bay. They went about their bees-ness, ignoring the photographer who was trying capture a few images of them. Hint: they do not brake for photographers.
The red pollen looked too massive to carry, but the bumbles--as entomologists call them--lumbered right along. Who says we can't fly?
Want to learn more about bumble bees? Read California Bees and Blooms: A Guide for Gardeners and Naturalists (Heyday, 2014), the work of University of California scientists Gordon Frankie, Robbin Thorp, Rollin Coville and Barbara Ertter. Legendary bee expert Robbin Thorp (1933-2009) emeritus professor, UC Davis Department of Entomology and Nematology, also co-authored Bumble Bees of North America: An Identification Guide (Princeton University, 2014).
- Author: Kathy Keatley Garvey
Happy Fly Day Friday!
If you've ever wondered why entomologists and insect enthusiasts post images of flies on Friday, not to worry.
They consider this "Fly Day." The Urban Dictionary defines Fly Day as "the day of the week when contract employees fly from their work site to their home location."
Flyday is also the seventh album by the German jazz rock band Kraan.
It also could be considered the day travelers depart on an airplane, or their "Day of Flight."
There's even a Flicker site called "Fly Day Friday." No, you don't have to take images of flies on Friday, but you must upload them on a Friday. To date: 526 members and 11.7K photos.
And there's even a #flyday hashtag on Twitter, where folks post everything from their flight plans to their weekend plans to images of...you-guessed-it!...flies.
This Bug Squad blog has always been a "no-fly zone" on Friday, but today it just seems like a good idea to post an image of three flies on a catmint leaf.
Were they having a family reunion or planning a fly-by into the kitchen? No, apparently, they just found a good spot to warm their flight muscles and bask in the sun.
(And look around for a picnic?)
Happy Fly Day Friday!
- Author: Kathy Keatley Garvey
Let's hear it for the sweat bee.
It's one of the many tiny bees that ought to be honored and recognized during Pollination Week, June 21-27, but it's often overlooked.
We've been seeing many of this species, Halictus tripartitus, in our pollinator garden in Vacaville. It's also called the "Tripartite Sweat Bee."
Thomas "Tom" Zavortink, a research entomologist and associate at the Bohart Museum of Entomology, UC Davis Department of Entomology and Nematology, noted why this one is Halictus tripartitus. "The abdominal terga appear to have apical hair bands, suggesting Halictus, and the scutum appears to have a slight metallic coloration, which along with the small size suggests Halictus tripartitus." Zavortink focuses on the systematics and biology associated with mosquitoes and solitary bees.
Check out BugGuide and Discover Life to see some excellent images of this species. The Great Sunflower Project also zeroes in on this species on this page.
Most Halictus are generalist foragers, according to the Great Sunflower Project. "They use all sorts of genera of plants from the Asteraceae to Scrophulariaceae. They are very common on composites (daisy-like disc and ray flowers) in summer and fall."
We've seen them on everything from mustard to milkweeds to catmint to rock purslane, from spring to fall. They also appear regularly on the tower of jewels (Echium wildpretii).
Let's hear it for the sweat bee, an overlooked and underloved little pollinator.
