- Author: Kathy Keatley Garvey
That would be the cabbage white butterfly, Pieris rapae.
Its larvae or cabbageworms are pests of our cole crops, including cabbage, kale and mustard.
Pests? You bet.
According to the UC Statewide Integrated Pest Management (UC IPM) Program, the caterpillars "feed voraciously on both the outer and inner leaves, often feeding along the midrib, at the base of the wrapper leaves, or boring into the heads of cabbage. After 2 to 3 weeks of feeding, larvae pupate attached by a few strands of silk to stems or other nearby objects; pupae are green with faint yellow lines down the back and sides; there is no spun cocoon. The adult cabbage butterfly is white with one to four black spots on the wings; they are often seen fluttering around the fields. The whitish, rocket-shaped eggs are laid singly on the undersides of leaves."
Furthermore, UC IPM points out in its Pest Management guidelines, "the cabbageworm is active throughout the year in California."
So, what good are they?
Well, National Public Radio says we should thank them. In a piece titled "Why You Should Thank A Caterpillar For Your Mustard And Wasabi," NPR author Jessica Rack relates that the caterpillars are responsible for the exquisite, pungent taste of wasabi and mustard. Basically, they are the engine that drives the plants to make the chemicals in these substances that we find so tasty.
Scientists published their work this month in Proceedings of the National Academy of Sciences. Plant evolutionary biologist Chris Pires of the University of Missouri, a lead author of the study, compared the evolution of taste to a military arms race or what Rack described as "repeated escalations to have better weapons or defenses — but on an epic timescale."
"In this case, the opposing armies are caterpillars of the cabbage butterfly and plants in the order Brassicales, which today includes cabbage, horseradish, kale and mustard," wrote Rack.
Ironically, in another paper, this one published Aug. 10 in the journal, Nature Climate Change, scientists are worried that the cabbage white butterfly might go extinct in the UK because these are drought-sensitive butterflies. The paper, titled "Interacting Effects of Climate Change and Habitat Fragmentation on Drought-Sensitive Butterflies," should draw a lot of attention.
Pieris rapae already does in central California. Butterfly expert Art Shapiro, distinguished professor of evolution and ecology at the University of California, Davis, annually conducts a contest involving the cabbage white. The first person to find the first cabbage white of the year in the three county area of Sacramento, Yolo and Solano wins a pitcher of beer. A beer for a butterfly.
The contest, launched in 1972, is all part of Shapiro's four-decade study of climate and butterfly seasonality. “It is typically one of the first butterflies to emerge in late winter. Since 1972, the first flight has varied from Jan. 1 to Feb. 22, averaging about Jan. 20.”
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- Author: Kathy Keatley Garvey
If you plant it, they will come.
Western tiger swallowtails (Papilio rutulus) can't get enough of our butterfly bush. For the first time ever, we saw two of them and managed to get both in the same image. Courtship? Curiosity? Chance encounter?
Whatever it was, they came together, touched and flew away.
Butterfly expert Art Shapiro, distinguished professor of evolution and ecology at the University of California, Davis, says that "the Western tiger swallowtail is basically a species of riparian forest, where it glides majestically back and forth along the watercourse. It has expanded into older urban neighborhoods where several of its host genera are grown as shade trees, and behaves as if the street were a watercourse. In the high country and on the Sierran east slope its usual host is Aspen.
"One brood (June-July) at higher elevations; one and a partial second at Washington; 2-3 at lower elevations with a long flight season (late February or March-September or October). An avid puddler. Visits Yerba Santa, California Buckeye, Milkweed, Dogbane, Lilies, Coyotemint, etc., etc. and in gardens frequent at Lilac and Buddleia. Spring individuals are smaller and usually paler than summer. Low-elevation hosts include Sycamore (Platanus), Ash (Fraxinus), Cherry and other stone fruits (Prunus), Willow (Salix), Privet (Ligustrum), Lilac (Syringa) and (in Sacramento County) Sweet Gum (Liquidambar)."
Nevertheless, "the tiger" is common in Western America and its bright yellow and black markings with its blue and orange spots on its tail is a sight we never tire of--even when parts of the swallowtail are missing. Predators, such as birds, praying mantids and spiders, try to grab it.
They may have a "tiger" by the tail, but that doesn't mean they can hold on.
- Author: Kathy Keatley Garvey
Ever heard of Schinia sueta?
It's a moth.
We spotted this little moth, from the Noctuidae family, in a meadow at the Hastings Preserve in Carmel in early May during the BugShot Macro Photography Course, taught by Alex Wild, John Abbott and Thomas Shahan.
The day-flying moth, as identified by butterfly experts Art Shapiro of UC Davis and Greg Kareofelas, an associate of the Bohart Museum of Entomology, stood out.
Schinia sueta is widespread in western North America. We were waiting for it to spread its wings in the meadow, filled with lupine, vetch and California golden poppies, and it finally did!
Speaking of moths, the Bohart Museum is hosting a "Moth Night"--the first of its kind held by the museum--on Saturday night, July 18 from 8 to 11 just outside its location, 1124 Academic Surge on Crocker Lane, UC Davis campus. Yes, that's 8 to 11. At night.
You'll learn how to collect moths and how to identify them. You won't see Schinia sueta, but you'll see other moths! The event is free and open to the public. It's also the last weekend open house of the academic year.
The Bohart Museum houses a global collection of nearly eight million specimens. It is also the home of the seventh largest insect collection in North America, and the California Insect Survey, a storehouse of the insect biodiversity. Noted entomologist Richard M. Bohart (1913-2007) founded the museum.
The museum's regular hours are from 9 a.m. to noon and 1 to 5 p.m. Mondays through Thursdays. The facility is closed to the public on Fridays and on major holidays. Admission is free. More information on the Bohart Museum is available by contacting (530) 752-0493 or Tabatha Yang, education and public outreach coordinator at tabyang@ucdavis.edu.
- Author: Kathy Keatley Garvey
The "Painted Ladies" are back in the Davis area.
These are not the two-legged type, but the winged type--Vanessa cardui.
They're migrating and driving UC Davis entomology and ecology students nuts. It's finals week and they'd love to be outdoors watching the migration instead of inside studying for their tests.
Butterfly expert Art Shapiro, distinguished professor of evolution and ecology, said that on Tuesday, March 17, St. Patrick's Day, "the front of a significant Painted Lady migration hit Davis about 7:30 this morning. I saw about 30 just in walking from Storer Hall to the Memorial Union bus terminal.
Shapiro then went to Gates Canyon, Vacaville, one of his field study sites, and saw more. It was 77 degrees at Gates Canyon (sorry, Bostonians!). He saw PLs all the way. He counted 81 in the canyon "but the apparent density in the open--Pleasants Valley, Vacaville--was much higher, with about 6 per minute in my field of vision."
"I imagine many were going over my head out of sight at Gates. Back in Davis I was seeing 10 per minute. This is about 1/6 of the density during the legendary 2005 migration."
"They are ALL large, fresh-looking, and on a solid SE-NW course, as usual stopping for nothing and going up and over all obstacles; very few are nectaring. We'll see how long it lasts! The condition suggests these are the offspring of a first round of breeding somewhere in Southern California--not direct from the deserts. We have an exceptional crop of milk thistle (Silybum) this year. May their offspring eat it all!"
You can read about the 2005 migration on Sharpiro's butterfly site. "This mass-migrant occurs in much of the Northern Hemisphere," he wrote. "Apparently the entire North American population winters near the US-Mexico border, breeding in the desert after the winter rains generate a crop of annual Malvaceous, Boraginaceous and Asteraceous hosts. The resulting butterflies migrate north."
Painted Ladies on the move. Painted Ladies everywhere. And more on the way. Life is good!
- Author: Kathy Keatley Garvey
He's never seen anything like it.
A pink cabbage white butterfly? Pieris rapae are not pink--they're white
Yet there it was, flying around Cypress Lane in West Davis around noon Thursday, March 15. It was sporting a new do, a strange pinkish/red hue.
"When I looked at it closely, I could see it had been 'sprayed' with a red color both top and bottom," said Greg Kareofelas, who wears several hats (he's an associate of the UC Davis Bohart Museum of Entomology; a naturalist who specializes in butterflies and dragonflies; and a photographer).
He shot out an email query, "Who's making pink rapae?"
"Someone COULD be trying to trace movements by making individuals highly visible, but I certainly haven't heard of it," replied butterfly expert Art Shapiro, distinguished professor of evolution and ecology at UC Davis who maintains Art's Butterfly World. It is Shapiro who conducts the annual "Beer for a Butterfly Contest," offering a pitcher of beer for the first Pieris rapae of the year in the three-county area of Sacramento, Yolo and Solano. (Hint: they're always white.)
"Looks to me like someone's doing a mark and recapture," said Lynn Kimsey, director of the Bohart Museum and a UC Davis professor of entomology. "I haven't heard of any project, though."
Meanwhile the pink rapae remains a mystery. An escapee from a lab? Part of a high school science project? The work of a prankster with leftover spray paint? A cucurbits project?
Anyone out there missing a pink rapae?