- Author: Kathy Keatley Garvey
Hello there, little leafcutter bee! Yes, you, foraging on the sky-blue Chinese Forget-Me-Nots!
You're just in time for National Pollinator Week!
Leafcutter bees, family Megachilidae, are so named because the females cut leaves and petals (perfectly round holes!) to line their nests. Smaller than honey bees--and much faster, leafcutter bees are easily recognizable by the black-white bands on their abdomen.
The females do all the work. They gather pollen and nectar, make the nests from the leaf and petal fragments, and lay eggs. They seal the egg chambers with the leaves or flower petals.
In our pollinator garden, leafcutter bees are quite fond of Chinese Forget-Me-Nots, Cynoglossum amabile. "Many wild bees prefer flowers in the violet-blue range—in part because these blossoms tend to produce high volumes of nectar," according to an Oct. 18, 2017 article in Science.org.
Of the 4000 bee species known in the United States, about 1600 reside in California. The leafcutter bee is just one of them. The family, Megachilidae, includes these leafcutting bees:Megachile angelarum, M. fidelis and M. montivaga; the alfalfa leafcutting bee, M. rotundata; the Mason bee, Osmia coloradensis; and the blue orchard bee (BOB), Osmia lignaria propinqua.
For more information on California's bees, read California Bees and Blooms: A Guide for Gardeners and Naturalists (Heyday), the work of UC-affiliated scientists,
Thorp, a global and legendary authority on bees and a distinguished emeritus professor of entomology at UC Davis, died June 7, 2019 at his home in Davis. He was 85.
/span>- Author: Kathy Keatley Garvey
Hey, the sun's up! It's time to rise and shine! Maybe I'll shine before I rise...or maybe I'll...
Anyway, I just woke up, and I'm starting to stir. I'm ready to conquer the day. I shall
- Sip nectar
- Seek girlfriend
- Guard the flower patch by dive-bombing and chasing off all critters.
- Repeat.
The scenario: a male longhorned bee, Melissodes agilis, has just spent the night sleeping--and quite cozily at that--on a Mexican sunflower, Tithonia rotundifola.
He is Boy Bee With the Green Mesmerizing Eyes.
Boy Bee With the Green Mesmerizing Eyes does not know--nor would he care if he could--that today is the beginning of National Pollinator Week, an international annual event celebrating pollinator health.
According to the Pollinator Partnership, "pollination is a vital stage in the life cycle of all flowering plants. When pollen is moved within a flower or carried from one flower to another of the same species it leads to fertilization. This transfer of pollen is necessary for healthy and productive native and agricultural ecosystems." It's crucial to our ecosystem.
As the Pollinator Partnership says on its website:
- "About 75 percent of all flowering plant species need the help of animals to move their heavy pollen grains from plant to plant for fertilization."
- "About 1,000 of all pollinators are vertebrates such as birds, bats, and small mammals."
- "Most pollinators (about 200,000 species) are beneficial insects such as flies, beetles, wasps, ants, butterflies, moths, and bees."
But back to Boy Bee With the Mesmerizing Green Eyes.
Noted bee expert, the late Robbin Thorp, a UC Davis distinguished emeritus professor of entomology and co-author of California Bees and Blooms: A Guide for Gardeners and Naturalists (Heyday), used to talk about these little guys bullying all the floral tenants--from honey bees to syrphid flies to butterflies to lady beetles--and more.
Boy, do they move fast. A good time to photograph them is when they're sleeping or just waking up. Otherwise, try to capture images of them at a shutter speed of about 1/5000 of a second.
Happy Beginning of National Pollinator Week!
- Author: Kathy Keatley Garvey
It's Day 6 of National Pollinator Week.
Meet the drone fly (Eristalis tenax), often mistaken for a honey bee.
The late Robbin Thorp, UC Davis distinguished emeritus professor of entomology, used to jokingly call it "The H Bee," pointing to the "H on its abdomen.
It's not a bee, though, it's a fly. It belongs to the family Syrphidae (which includes insects commonly known as syrphids, flower flies, and hover flies) in the order, Diptera.
The drone fly about the size of a honey bee. However, unlike a honey bee, the drone fly "hovers" over a flower before landing.
Drone fly larvae are known as rattailed maggots. They feed off bacteria in drainage ditches, manure or cess pools, sewers and the like.
But just think of the adult. It's a pollinator. Just like the honey bee.
- Author: 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.
- Author: Kathy Keatley Garvey
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.