Visitors to the UC Statewide Integrated Pest Management Program (UC IPM) display in front of Briggs Hall at the 101st annual Picnic Day last Saturday at the University of California, Davis, got a close look at the Pipevine Swallowtail caterpillar.
While the visitors watched or held them, the other caterpillars kept busy, munching on the leaves of their host plant, the pipevine.
Butterfly expert Art Shapiro, distinguished professor in the UC Davis Department of Evolution and Ecology, has seen lots of Pipevine Swallowtails (Battus philenor) already this year. "There are plenty," he said today. "Don't eat 'em; they're quite poisonous."
Both the caterpillar and the adult are poisonous. The caterpillars of the Pipevine Swallowtail feed on the poisonous host plant, Aristolochia, also known as the pipevine, Dutchman's pipe or birthwort. It contains the lethal toxin aristolochic acid.
Nevertheless, the black caterpillars turn into beautiful adults. Found throughout North America and Central America, they are black with iridescent blue hind wings. Their wingspan can exceed three inches.
"The Pipevine Swallowtail flies from late winter (February-March) to autumn (October, occasionally November) but is much more numerous before the 4th of July than later; typically it has two large flights followed by stragglers the rest of the season, often with a 'blip' upward in August," Shapiro writes on his website. "Usually the host plant stops growing in June, and thereafter there are no sites suitable for egg-laying--unless there is a local catastrophe (usually fire, though weed-whacking will do). Then the plants regenerate rapidly, producing new growth in the off-season, and any females around at the time quickly find and make use of the new shoots. Adults routinely live a month or so."
"This species is warningly colored and inedible to vertebrate predators," Shapiro points out. "It derives its protection from the toxic aristolochic acids produced by the host, which it sequesters; females even pass these along to the eggs, which are also protected (and are brick red, laid in bunches of up to 20, and quite conspicuous)."
"Adults are eager visitors to many flowers, including Wild Radish, California Buckeye, Blue Dicks, Ithuriel's Spear, and Yerba Santa," Shapiro notes. "In summer they regularly nectar at Yellow Star Thistle when there are no native plants in bloom."
We've seen many of the Pipevine Swallowtails fluttering around in the UC Davis Arboretum and gathering nectar from butterfly bushes.
A word of warning from Shapiro: "Don't eat 'em; they're quite poisonous."
Butterfly expert Art Shapiro, distinguished professor of evolution and ecology, excitedly points to a Pipevine Swallowtail nectaring on roadside radish.
“Battus philenor! Battus philenor!”
It's the earliest he's ever seen the Pipevine Swallowtail in Gates Canyon, Vacaville, one of his 10 fixed study sites in California's Central Valley.
It is Saturday, Jan. 25. Another day to monitor the butterfly population, something he's been doing for 42 years. He posts much of his information on Art's Butterfly World.
Shapiro has trekked up Gates Canyon since 1976. He aims for 26 visits a year. In 2013 he totaled 32 visits. In a typical season, he finds approximately 30 to 40 butterfly species, "but that's not reached every year by any means," he points out. "Last year the maximum was 31."
It's a long way up and back. Shapiro, who doesn't drive a motor vehicle, rides a bus from Davis to the Vacaville bus station, then walks three miles from downtown Vacaville to Gates Canyon Road; up the road three miles and down three miles; and back to the bus station. That's a total of 12 miles.
Shapiro works his route easily. He's like an Olympic skater as he walks up the hill: hands folded behind his back and sometimes on his hips; eyes constantly sweeping for the count. He can, and does, detects the slightest movement, the slightest rustling of leaves, the slightest flutter of wings.
This Saturday Art Shapiro records eight different species of butterflies or a total of 18 individuals. And not just butterflies: he spots a yellow-faced bumble bee, Bombus voznesenskii, nectaring on radish next to a Pipevine Swallowtail.
Overall, it's a good day for "earlies." On Saturday, he sees his earliest Pieris napi, a Gray-Veined White, which beats his record of Jan. 31, 1984; his earliest Incisalia iroides, a Western Brown Elfin, eclipsing his previous records of Jan. 31 in 1976 and 1984; and his second earliest Erynnis propertius, Propertius Dusky-Wing, since Jan. 22, 1990.
Gates Canyon is bone dry. The thirsty hills and the dry creek beds ache for water. Alamo Creek, at the lower elevations, holds no water at all. At the higher elevations, the creek bed just trickles.
Shapiro's records shows that on Jan. 24, 1976, "under extreme drought conditions, I had 10 species flying at Gates Canyon. Today (Jan. 25, 2014), I had 8. Of these, only 2 were flying in '76." That amounted to 80 percent from what he detected on Jan. 24, 1976.
Shapiro keeps meticulous notes. His Jan. 25th notes include:
"Mid-70s, 90 percent sunshine (again, a few patchy altocumulus), light noth wind not getting into the upper canyon at all. No water in Alamo Creek at lower elevations; a bit more above than on Jan. 15, actually trickling audibly in spots. Vegetation little changed: alder and bay, nothing else in upper canyon (got up to ridgetop, where there is patchy bloom of manzanita and winter currant) except a totally anomalous native Lathyrus high on a sunlit, warm rock face, being visited by Battus (but I'm getting ahead of myself); somewhat more Raphanus down below, and very little Brassica. Aristolochia still dormant. The infamous 'poison oak tree' is leafing out but most poison oak is not. A few really small buckeyes are now in early leaf; hardly any green showing on big ones, even S-facing ones. No trace of Asclepias fascicularis. No Dentaria in flower and no detectable rosettes of Dodecatheon! Few birds. Still no Phainopepla. Deer and quail; no newts; no amphibian calls."
The 18 butterfly species he sighted at his Gates Canyon study site on Jan. 25:
- Battus philenor (Pipevine Swallowtail): 5 (new earliest at Gates)
- Polygonia satyrus (Satyr Anglewing): 1
- Nymphalis antiopa (Mourning Cloak): 5
- Celastrina ladon echo (Echo Blue): 3
- Pieris napi (Gray-Veined White): 1 (female-probably earliest ever)
- Incisalia augustinus iroides (Western Brown Elfin): 1
- Erynnis propertius (Propertius Dusky-Wing): 1
- Colias eurytheme (Orange Sulphur or Alfalfa Butterfly): 1
Shapiro worries about the drought. On Tuesday, Jan. 28, he recorded: "Today was the 52nd and last consecutive day with no rain in winter--a record probably never to be equaled in any of our lifetimes (I hope)."
Meanwhile, his other nine study sites in the Central Valley await him. They are all over the map, just as he is. As he says on his website: "Ranging from the Sacramento River delta, through the Sacramento Valley and Sierra Nevada mountains, to the high desert of the western Great Basin, fixed routes at ten sites have been surveyed at approximately two-week intervals since as early as 1972. The sites represent the great biological, geological, and climatological diversity of central California."
If you're lucky enough to accompany him on a survey, you'll hear him point out butterflies as excitedly as a winner yells "Bingo! Over here! Over here!"/span>
Butterfly expert Art Shapiro, distinguished professor of evolution and ecology at the University of California, Davis, monitors butterfly populations throughout the Central Valley, including Gates Canyon, Vacaville, Solano County.
Gates Canyon is one of his "stomping" grounds, or "monitoring" grounds.
And that's where we saw about half-a-dozen butterflies fluttering on Jupiter's Beard (Centranthus ruber), also known as Red Valerian. The perennial is native to the Mediterranean region.
The pipevine swallowtail (Battus philenor) is what Shapiro calls "the signature riparion butterfly of our region (Northern California), occurring along streams in foothill canyons and on the Central Valley floor, essentially everywhere its only host plant, California pipevine or Dutchman's Pipe, Aristolochia californica, occurs."
"This species is warningly colored and inedible to vertebrate predators," Shapiro says on his website. "It derives its protection from the toxic aristolochic acids produced by the host, which it sequesters; females even pass these along to the eggs, which are also protected (and are brick red, laid in bunches of up to 20, and quite conspicuous).
Brick-red eggs? That must be a sight and a delight to see!
You can read more about the pipevine swallowtail on his website.
The first time we ever saw a pipevine swallowtail, it was in the clutches of a hungry praying mantis. (See photo on my Flickr site.)
So it's good to see it "whole."
When I last met up with a pipevine swallowtail, it wasn't faring well.
In fact, I didn't recognize it as a pipevine swallowtail (Battus philenor), no thanks to it being in the clutches of a hungry praying mantis.
Mantids have to eat, too, but I'd prefer they express an culinary interest in pests such as spotted cucumber beetles instead of beneficial insects.
On his website, butterfly expert Art Shapiro, professor of evolution and ecology at the University of California, Davis, calls the pipevine swallowtail "the signature riparian butterfly of our region, occurring along streams in foothill canyons and on the Central Valley floor, essentially everywhere where its only host plant, California pipevine or Dutchman's pipe, Aristolochia californica, occurs."
If you head out to the Storer Garden in the UC Davis Arboretum, you might see a pipevine swallowtail catching the breeze, stopping here and there to nectar a plant.
Maybe this time a praying mantis will catch something else.
Robert Bugg saw it first.
That's entomologist Robert L. Bugg.
Bugg, who received his doctorate in entomology at UC Davis, does research on the biological control of insect pests; cover crops; and restoration ecology.
And he saw it first.
“Look,” he said. “That praying mantis just bit the head off a pipevine swallowtail butterfly.”
We were part of a field tour, “Yolo County Field Tour of Native Bee Habitat on Working Lands.” Held Wednesday, Aug. 27 and organized by the Native Pollinators in Agriculture Project, the field tour drew representatives from the U.S. Department of Agriculture, California Department of Agriculture, California EPA, and farmers from throughout the country.
We visited seven sites: The Farm on Putah Creek, Butler Farm, Good Humus Farm, Cache Creek Conservancy, Muller Farms, Hedegrow Farms, and the Pioneer Hybrid Seed Farm.
I brought along my camera and a macro lens to capture photos of native pollinators, such as long-horned bees, sunflower bees, sweat bees and bumblebees.
We saw the green praying mantis, disguised as a flower stem or blade of grass, at The Farm on Putah Creek.
It had just snared a pipevine swallowtail butterfly (Battus philenor).
It was survival of the fittest, and the matnis was more than fit. Now he was enjoying a morning meal at the expense of a fluttering butterfly.
The praying mantis (sometimes called a "preying matnis") is an ambush predator. It lies in wait for unsuspecting dinner to arrive.
Mr. Mantis grasped the butterfly in his spiked forelegs and chewed off the head.
It was a good day for a praying mantis, a bad day for a butterfly.