Life is not always sunny for the sunflower bee, Svastra obliqua, a native longhorned bee.

The gals have trouble foraging when a male longhorned bee, Melissodes agilis, targets them.

The male M. agilis are very territorial--and their kamikaze-like maneuvers are spectacular.

The gal Svastras try to ignore them until the dive-bombing results in direct hits.

We saw this female foraging this week on a Mexican sunflower, Tithonia rotundifola. We also saw her bolt after the male M. agilis hit his mark. Gotcha!

Score:

Male Melissodes agilis: 1
Female Svastra obliqua expurgata: 0.

(For more information on these two species and other bee species in California, see the Heyday publication, California Bees and Blooms: A Guide for Gardeners and Naturalists, the work of UC-affiliated scientists Gordon Frankie, Robbin Thorp (1933-2019), Rollin Coville and Barbara Ertter. It's available on the UC ANR website and on other sites. Also access the YouTube video on Svastras by The Bees in Your Backyard.) 

Close-up image of a male Melissodes agilis as it greets a new day. (Photo by Kathy Keatley Garvey)

Don't bring a pillow, a night-cap or an attitude—it's Boys' Night Out and we're sleeping outside on the flowers.

That's what the male longhorned bees, Melissodes agilis, do while the females return to their underground nests at night.

"It's a bee B&B," quipped Lynn Kimsey, director of the UC Davis Bohart Museum of Entomology and distinguished professor, UC Davis Department of Entomology and Nematology.

This native species is among California's 1600 species of undomesticated bees.

Ever seen a Boys' Night Out? It's fascinating. The boys curl into a comma, or doze with their heads down and striped abdomens up.  

Over the last two weeks, we've been monitoring the number of males sleeping on a single Mexican sunflower, Tithonia rotundifola, in our Vacaville pollinator garden. On the first night, two. Then three, then four. The slumber party grew to five last night. They sleep on a 10-foot-high blossom (talk about height advantage and a bird's eye view)!  Every night, they return to the very same blossom.

A few years ago we saw the males sleeping on our lavender stems and then they moved to Gaura stems, probably due to the proximity of three praying mantids.

Folks ask if they sting. No. Boy bees don't sting. They can't.

The late Robbin Thorp, distinguished emeritus professor of entomology and co-author of California Blooms and Bees: an Identification Guide for Gardeners and Naturalists, fielded scores of questions on these slumbering bees. “They (males) lack a stinger which is a modified ovipositor in their wasp ancestors. Boy sleeping aggregations are based on a suitable perch and not related to where females are nesting, but probably no more than 100 yards from the nearest female nest. Females nest in the ground and have rather distinctive round holes about the diameter of a pencil or slightly smaller, sometimes with small piles of dirt around them looking like mini-volcanos.  The holes may be widely separated or clustered together depending on the species, but each female digs her own burrow."

Of course, not all slumbering bees in this area are Melissodes agilis, as Thorp pointed out. Some may be other species of the genus Melissodes and some may belong to the closely related Svastra obliqua.

The boy bees start arriving for their nightly sleepover around 5 p.m. or when the light fades. Sometimes they appear to be kicking each other before settling down for the night. Said Thorp: "Each establishes his own spot, so there may be some jostling for position initially." 

When it's morning, they rise, warm their flight muscles, sip a little nectar, and begin dive-bombing the honey bees, carpenter bees, bumble bees, butterflies, syrphid flies and assorted other insects on "their" flowers.  M. agilis are very territorial. They're trying to save the food source for the females of their own species—so they can mate with them, as Thorp related.

When their day ends, they cluster for another Boys' Night Out. It's "Nighty Night, Sleep Tight." Time to curl up on a cushion of petals beneath a blanket of stars.

"Bee B&B," as Professor Kimsey says.

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 was July 3, 2020.

The male bees, Melissodes agilis, were getting quite territorial.

Every time a butterfly, a honey bee or another insect in our family's pollinator garden expressed an interest in foraging on the Mexican sunflowers, Tithonia rotundifola, a male Melissodes buzzed them. 

"Get out of here!" he threatened. "I own these flowers. These are mine!"

What to do? I grabbed my Nikon D500 and 200 mm macro lens, adjusted the settings to 1/5000 of a second, f-stop 5.6, ISO of 800, and managed to get a shot of the menacing bee confronting a bewildered monarch.

Eye-to-eye. Antenna-to-antenna. Wing-to-wing.

What happened? The monarch quickly escaped the wrath. 

And the bee? It buzzed off, only to return to target another insect.

"Get out of here! I own these flowers. These are mine!"

Another tiff on the Tithonia. Another round on the rotundifola. 

Just another day in the pollinator garden.