It's a strikingly beautiful insect.
But in its larval stage, the alfalfa butterfly, Colias eurytheme--also known as the orange sulphur butterfly--is a pest.
If you grow alfalfa, you're not a fan of this butterfly, and rightfully so.
"Alfalfa caterpillars can consume entire leaves," according to the UC Statewide Integrated Pest Management Program (UC IPM) website. "The larger larvae are most destructive."
The butterfly lays its eggs "on the new growth of alfalfa that is less than 6 inches tall," UC IPM says. "Eggs hatch into green caterpillars in 3 to 7 days. Full-grown caterpillars are about 1.5 inches long and are distinguished from other caterpillars on alfalfa by their velvety green bodies with white lines along their sides."
"Caterpillar populations usually result from a flight of butterflies into the field when the alfalfa is less than 6 inches tall. Extremely large numbers of adults migrating between fields are often present from June to September in the Central Valley and from May to October in the southern desert."
We've been seeing lots of alfalfa butterflies sipping nectar on our African blue basil (Ocimum kilimandscharicum × basilicum 'Dark Opal').
Sometimes they don't notice you and you can edge toward them, camera in hand.
Sometimes they don't even notice that a honey bee is shadowing them. Honey bees are also quite fond of African blue basil.
Butterfly meet bee. Bee meet butterfly.
In the insect photography world, that's called a "two-fer"--a bonus of two insects in one photo.
It was a good day for a crab spider.
It was NOT a good day for a honey bee.
It's early evening and here's this bee foraging on a bluebeard plant, Caryopteris x clandonensis, totally unaware of the ambush predator lying in wait.
The hunter and the hunted.
A venomous bite and it's all over.
These spiders, often called the "white death spider," are camouflage artists. They can turn colors, from yellow to white, or white to yellow. You'll often see yellow crab spiders on golden rod Solidago or a predominantly yellow plant, like blanketflower, Gallardia.
"These spiders change color by secreting a liquid yellow pigment into the outer cell layer of the body," according to Wikipedia. "On a white base, this pigment is transported into lower layers, so that inner glands, filled with white guanine, become visible. The color similarity between the spider and the flower is well matched with a white flower, in particular the Chaerophyllum temulum, compared to a yellow flower based on the spectral reflectance functions."
"If the spider dwells longer on a white plant, the yellow pigment is often excreted," Wikipedia says. "It will then take the spider much longer to change to yellow, because it will have to produce the yellow pigment first. The color change is induced by visual feedback; spiders with painted eyes were found to have lost this ability. The color change from white to yellow takes between 10 and 25 days, the reverse about six days. The yellow pigments have been identified as kynurenine and 3-hydroxykynurenine."
One thing's for sure: everybody eats in the pollinator garden.
The honey bee and the Painted Lady.
Apis mellifera and Vanessa cardui.
They both wanted to sip that sweet nectar from a mustard blossom.
The Painted Lady was there first. Sometimes it's "first come, first served" and sometimes it's "I'll have what she's having."
The persistent bee managed to forage a bit around the blossom, but the butterfly, just as persistent, stayed put.
Finally, the bee buzzed over the butterfly, nearly touching it, as it headed for new territory.
Meanwhile, the cardui migration continues, from California through the Pacific Northwest. Millions have already moved through the Davis/Sacramento area on their way up north.
"It's Week 11, Day 81," says butterfly guru Art Shapiro, UC Davis distinguished professor of evolution and ecology. "It's almost over (through this area)."
An article published May 19 in the Idaho Statesman, Boise, announced that "Hundreds of Butterflies Flitted Through Boise This Weekend."
"This weekend, Boiseans found themselves in the middle of a massive migration as hundreds of orange-and-brown butterflies known as painted ladies winged their way through the area," wrote reporter Nicole Blanchard. "Dozens of people on social media shared accounts of seeing the butterflies flying overhead en masse or stopping to snack on spring blooms. Many of the painted lady butterflies, which are often mistaken for monarchs because of their orange coloring, were spotted in the North End and Foothills on Saturday."
One Boise resident related on Twitter that she saw 56 flying northwest through her yard in a period of two minutes.
Want to learn more about Painted Ladies and other butterflies? Check out Art Shapiro's website. He's been monitoring the butterfly populations of Central California since 1972.
On Vanessa carduii: The mass migration begins near the U.S.-Mexico border, Shapiro says. They breed "in the desert after the winter rains generate a crop of annual Malvaceous, Boraginaceous and Asteraceous hosts. The resulting butterflies migrate north. In good years (lots of desert rain) they may do so by billions, interfering with traffic and attracting the attention of the media. 2005 was one of the biggest Painted Lady years in history--perhaps the biggest," he says. This year was also a very good year.
"They do not stop to feed or have sex until they have burned up their reserves, carried over from the caterpillar stage," according to Shapiro. "They fly in a straight line from SE to NW, like 'bats out of Hell,' and go over obstacles rather than trying to go around them. (On certain days there may be concerted local movements in the wrong direction. We do not understand these.) Painted Ladies tend to fly parallel to the Sierra Nevada, not across it. They enter the Central Valley through the Inyo-Kern lowland or by crossing the Transverse Ranges. They can apparently make it from Bishop to Davis in three days. In some years the migration is heavier in the Great Basin and on the East slope of the Sierra than farther west. The Painted Lady moves northward in a generational wave as the season progresses. Frequently it disappears altogether from the lowlands in summer. Beginning in August the movement reverses and butterflies head south toward the desert wintering grounds. The southward migration is a more protracted affair, with plenty of adult feeding and some breeding en route. Numbers tend to be highest east of the crest, on Rabbitbrush blossoms in October."
It's been a very good year for these orange-black butterflies, which began arriving in the Davis/Sacramento area on March 17. Just don't confuse them with Monarchs! Shapiro can't begin to count the calls of folks telling him that the Monarch is no longer in trouble; that "there are millions of them!"
They can't drain your bank account. They can't open up new credit cards. They can't get medical treatment on your health insurance.
But they are identity thieves, nonetheless.
Meet the drone fly (Eristalis tenax), often mistaken for a honey bee.
Indeed, it's about the size of a honey bee. In its adult form, it's a pollinator, just like the honey bee.
Unlike a honey bee, however, the drone fly "hovers" over a flower before landing. And unlike a honey bee, the drone fly has one set of wings, large eyes, stubby antennae, and a distinguishing "H" on its abdomen. Robbin Thorp, UC Davis distinguished emeritus professor of entomology, jokingly calls the drone fly "The H Bee."
Drone fly larvae are known as rattailed maggots. They feed off bacteria in drainage ditches, manure or cess pools, sewers and the like.
The fly belongs to the family Syrphidae (which includes insects commonly known as syrphids, flower flies, and hover flies) in the order, Diptera. The honey bee is Apis mellifera, family Apidae, order Hymenoptera.
One's a fly. One's a bee.
Lately we've been seeing scores of drone flies nectaring on our Mexican sunflower (Tithonia).
Identify thievery does have its advantages. Wary people and predators often shy away from drone flies, thinking they are honey bees and might sting them.
Drone flies can't sting. They can't drain your bank, either.
So you're walking along Doran Regional Park Beach in Sonoma County on Tuesday, Oct. 16 and thinking about the pollinators in your back yard. (Don't we all?)
And then: what a delight to see. Apis mellifera (honey bees) and Eristalis tenax, syrphid flies (better known as a "drone flies") nectaring on the tiny blossoms of a sea rocket plant (genus Cakile).
This particular plant species? The European sea rocket, Cakile maritima, a succulent annual that's a member of the mustard family. It grows in clumps or mounds on sandy beaches and bluffs along the coastlines of North Africa, western Asia, and North America. It boasts a long, slender and stout taproot.
You've probably seen it. But you may not have noticed the pollinators.
"Their leaves are fleshy," is how Wikipedia describes the plant. "Flowers are typically pale mauve to white, with petals about 1 cm in length. Each fruit has two sections, one that remains attached to the adult, and the other which that falls off for dispersal by wind or water."
At Doran Beach, two species of sea rocket (C. maritima or European sea rocket, and C. edentula or American sea rocket) bloom from spring through summer--and sometimes in early fall.
Bees at the beach? Floating fruit?
And flies (syrphids), too.