Day 5 of National Pollinator Week: Meet the leafcutter bee, family Megachilidae.

It's a native pollinator, a solitary bee,  and about the size of a honey bee.   

Its coloration--the black-and-white banded abdomen--makes it easily recognizable.

As the name suggestions, they (the females) cut circular holes in leaves to line their nests for brood-rearing.  Rosarians who enter their roses in competition aren't fond of them because of the "imperfections" in the leaves. A hole in one--or holes in many--aren't going to give them a whole lot of blue ribbons.

But having leafcutter bees in your garden is a joy. They're good pollinators and gentle bees. Leafcutter bees carry pollen on the underside of their abdomen, not on their hind legs like honey bees, do.  Agriculturists manage the alfalfa leafcutter bee (Megachile rotundata) for crop pollination.

Leafcutter bees nest in natural cavities, mostly holes in soft wood or in hollow, pithy plant stems. You can also create bee condos or housing for them, drilling specific-sized holes in a block of wood. 

We saw this little male Megachile foraging on Verbena. He paused for a few minutes and then took flight. Things to do and places to go...

Lady beetles, aka ladybugs, are pollinators. These beneficial insects are known for eating scores of aphids. (Photo by Kathy Keatley Garvey)

And well you should: honey bees are the global workhorses of the pollination community and pollinate about one-third of the food we eat, including fruits and vegetables and some nuts, primarily almonds (California's almond acreage exceeds 1.6 million.) 

But to continue the alliteration--butterflies, bats, birds and beetles are pollinators, too. 

That includes "the good guys and gals," the lady beetles, aka ladybugs, which devour aphids.

However, this is National Pollinator Week and a good time to reiterate that insects can be both pollinators and pests. Take the blister beetles (family Meloidae, which contains about 2500 species) are one color or striped.  Blister beetles are a pest of alfalfa and many species secrete a poisonous chemical called cantharidin, which protects  them from their predators but is quite toxic to livestock, especially horses.  

According to the Alfalfa Pest Management Guidelines published by the UC Statewide Integrated Pest Management Program (UC IPM): “Blister beetles do not cause widespread feeding damage to alfalfa; however, they contain a chemical, cantharidin, which is toxic to livestock. Cantharidin is contained in the hemolymph (blood) of the beetles, and can contaminate forage directly, when beetles killed during harvest are incorporated into baled hay, or indirectly, by transfer of the hemolymph from crushed beetles onto forage. Horses are particularly susceptible to the toxic effects of cantharidin. Consuming as few as six beetles can kill a horse.”

A 2020 news story out of the Midwest related that beetle-infested hay purchased at an auction in South Dakota led to the deaths of 16 horses at a riding stable in Mauston, Wisconsin. Reporter Carleen Wild wrote that even a small amount of the bug itself or cantharidin "can be toxic enough to kill a horse within 72 hours." The horse owners reported what looked like "blisters and holes down their esophagus and throughout their insides."

The odorless, colorless chemical also blisters the human skin; physicians use it to remove warts. 

That's one powerful chemical.

It's Day 3 of National Pollinator Week.

Fortunately, a tiger came to visit us--no, not the predatory jungle animal, Panthera tigris, but a newly emerged Western tiger swallowtail, Papilio rutulus.

This native butterfly is quite colorful, with black stripes accenting its brilliant yellow wings, and blue and orange spots gracing its tail. When it flutters into your garden, you stop everything you're doing and become a professional butterfly watcher until it leaves. It's the law, I think. Anyway, Western tiger swallowtails are almost hypnotic. 

This fluttering tiger took a liking to our Mexican sunflower, Tithonia rotundifola, and was totally unaware of a tiny longhorned bee, a male Melissodes agilis, heading straight for it.

Pretend you're the butterfly. Here you are, newly emerged and you've discovered a patch of Tithonia offering delicious nectar! Heaven scent! Then you see a speedy little critter targeting you. He's not about to make a lane change. There's no garden patrol to monitor his speed or aggressive behavior. He's coming for you. He aims to hit you and dislodge you from your perch.

This little bee, in fact, targets all critters occupying "his" flowers. He isn't out to sting the floral occupants, as one reader surmised. It's a male bee, and boy bees can't sting. Nor is he fighting over pollen. Males do not collect pollen or nectar for their colony--the females do.

So what is he doing? He's trying to protect or save the floral resources for the females of the species so he can mate with them. The late Robbin Thorp, noted bee expert and distinguished emeritus professor of entomology at UC Davis, used to talk about these little guys bullying all the floral tenants--from Valley carpenter bees to majestic monarchs to praying mantids. Sometimes an unfortunate Melissodes winds up in the spiked forelegs of a mantis.  Or in the clutches of a spider. Or in the beak of a bird.

It's a jungle out there. Sometimes it's the survival of the fittest. Or the flittest.

It's Day 2 of National Pollinator Week.

So, I guess I should "toot my own horn" (we don't have one, but in our household we do have a piano, a double bass,  a guitar, a banjo, a ukulele, a dulcimer, a harmonica, a sousaphone, a set of hand drums, and two accordions. Note that the last one to play the piano well was the...um...cat).

Yours truly of the UC Davis Department of Entomology and Nematology, just won a silver award or second-place honors, in a photography competition hosted by the international Association for Communication Excellence in Agriculture, Natural Resources and Life and Human Sciences (ACE).  ACE announced the awards today (June 22) at its virtual conference.

To draw attention to the plight of monarchs, I captured (with a Canon MPE-65mm lens) an image of a monarch egg in our family's pollinator garden where we create habitat for assorted bees and butterflies and other pollinators. 

“The purpose of my image is to draw attention to the dwindling monarch butterfly population,” I wrote on the form. “They are on life support.” The Xerces Society for Invertebrate Conservation's reports that overwintering monarchs have declined 99 percent in coastal California since the 1990s. 

I posted the image at https://bit.ly/3cUx358 Aug. 10, 2020 on my daily (Monday-Friday) Bug Squad blog on the UC Agriculture and Natural Resources website. 

Wrote the judge: “Capturing a subject this small is really quite impressive. I appreciate the photographer sharing their equipment and process to capture this image of such a delicate and beautiful little butterfly egg. Very well done.” 

The image scored 25 out of 25 points in creativity/originality, audience interest/impact, and overall evaluation. 

The egg, I commented, is “an incredible work of nature! The intricate egg is about the size of a pinhead, 0.9mm wide and 1.2mm high. It's creamy yellow with narrow longitudinal ridge. Unless it encounters a predator or parasitoid or another life-threatening factor, the egg will usually hatch 3 to 4 days after Mama Monarch deposits it beneath a milkweed leaf.” 

 “A good place to see butterfly specimens from all over the world is at the Bohart Museum of Entomology (now temporarily closed due to the COVID-19 pandemic)," I added. “Of the nearly eight million specimens in the Bohart, some 500,000 are in the Lepidoptera collection, curated by entomologist Jeff Smith.“  I also drew attention to the butterfly-rearing process of Bohart associate and natural historian Greg Kareofelas. 

In addition to the silver award, yours truly won a bronze award or third-place honors for my image of a photo series of male and female Gulf Fritillaries, Agraulis vanillae, “keeping busy.”  The Bug Squad post, “Fifty Shades of Orange, with a Touch of Silver,” appeared July 13, 2020 at  https://bit.ly/2Q6cU3q. 

Wrote the judge: “This submission was a delight! I adored the written piece that accompanied the photos, describing the insect wedding during COVID times. To take notice of these delicate creatures, which many people just pass by without noticing, and to document them in photos is unique…. When photographing subjects of this size, the tack-sharp focus which captures the details that our eyes cannot normally see is what makes them so captivating. It's also incredibly difficult to capture--the photographer did a lovely job.”

 “So there they were," I wrote. "The two of them. The blushing bride and the quite dapper-and-dashing groom. They didn't invite me to their wedding. I was an uninvited guest, the only guest. So, I felt obliged to crash their wedding and capture some images…Who can resist insect wedding photography? That's about the only wedding photography happening during the COVID-19 pandemic.”

I also drew readers to the research website of butterfly guru Art Shapiro, UC Davis distinguished professor of evolution and ecology, and his information on A. vanillae, (see  https://bit.ly/3uw9Yf1) and to specific work of insects “keeping busy” (see https://bit.ly/3rVU1xg) by UC Davis alumnus and renowned macro photographer Alex Wild, curator of entomology at the University of Texas, Austin.

ACE, founded in 1913 primarily for ag communicators,  is now an international association of professionals who practice in all areas of communication. 

(Editor's Note: Last year, three UC Davis-affiliated communication specialists won a total of six writing or photography awards in the ACE global competition for their work accomplished in 2019 (pre-COVID pandemic). Steve Elliott, communications coordinator for the Western Integrated Pest Management Center, Davis, won one silver (second-place) and two bronze (third-place) for his writing and photography; Kathy Keatley Garvey, communications specialist for the UC Davis Department of Entomology and Nematology, two silvers for her writing and photography; and Diane Nelson, communication specialist for the UC Davis College of Agricultural and Environmental Sciences, won a bronze for her writing.)