Long time passing
Where have all the flowers gone?
Long time ago
Where have all the flowers gone?
Girls have picked them every one
When will they ever learn?
When will they ever learn?"
The late folksinger and social activist Pete Seeger (1919-2014) sounded many alarms, but a recent article in the New York Times Magazine struck a different but somewhat similar chord: the declining population of insects worldwide.
Brooke Jarvis's piece on "The Insect Apocalypse Is Here," published Nov. 27, should be required reading.
Basically: Where have all the insects gone? What does it mean? Why haven't we noticed? And what are we going to do about it?
Well, butterfly guru/entomologist Art Shapiro, distinguished emeritus professor of evolution and ecology at the University of California, Davis, has noticed. Shapiro has monitored butterfly population trends on a transect across central California for 46 years and maintains a research website at http://butterfly.ucdavis.edu/. The 10 sites stretch from the Sacramento River Delta through the Sacramento Valley and Sierra Nevada mountains to the high desert of the Western Great Basin. Shapiro visits his sites every two weeks "to record what's out" from spring to fall. The largest and oldest database in North America, it was recently cited by British conservation biologist Chris Thomas in a worldwide study of insect biomass.
In her article, Jarvis related: "In October, an entomologist sent me an email with the subject line, “Holy [expletive]!” and an attachment: a study just out from Proceedings of the National Academy of Sciences that he labeled, “Krefeld comes to Puerto Rico.” (See news article on Krefeld's "Insect Armageddon.")
That entomologist was Art Shapiro.
Pesticides, loss of habitat, diseases, climate change, and human encroachment--and more--are some of the reasons why our global population of insects is dwindling.
Shapiro, who engaged in a 90-minute conversation with author Jarvis (and suggested topics and interviews for the piece), is quoted as having one of the few long-term data sets about insect abundance in the United States.
"In 1972, he began walking transects in the Central Valley and the Sierras, counting butterflies," Jarvis wrote. "He planned to do a study on how short-term weather variations affected butterfly populations. But the longer he sampled, the more valuable his data became, offering a signal through the noise of seasonal ups and downs. 'And so here I am in Year 46,' he said, nearly half a century of spending five days a week, from late spring to the end of autumn, observing butterflies. In that time he has watched overall numbers decline and seen some species that used to be everywhere — even species that 'everyone regarded as a junk species' only a few decades ago — all but disappear. Shapiro believes that Krefeld-level declines are likely to be happening all over the globe. 'But, of course, I don't cover the entire globe,' he added. 'I cover I-80.'"
Jarvis quotes plant ecologist Hans de Kroon of Radboud University, the Netherlands, as characterizing the life of many modern insects as trying to survive from one dwindling oasis to the next but with “a desert in between, and at worst it's a poisonous desert.”
Why should we care? As Jarvis succinctly points out: "Insects are the vital pollinators and recyclers of ecosystems and the base of food webs everywhere."
Now the concern should not only be "Where have all the insects gone?" but "What are we going to do about it?"
It was a dismal year in Vacaville (and other parts of California) for monarch-rearing. Of the 10 caterpillars we collected from milkweed in our pollinator garden in early September and tried to rear, only eight made it.
One caterpillar died when a sibling attacked it. Another caterpillar made it to the chrysalis stage, and then it succumbed.
"The intersegmental membranes are showing," observed butterfly guru Art Shapiro, UC Davis distinguished professor of evolution and ecology, who has researched butterflies for more than four decades and maintains a research website at http://butterfly.ucdavis.edu. "Whatever caused that, it opens the door to severe water loss, so the pupa will probably die."
Yes, it did.
Black lines rimmed the non-viable chrysalis, and then it deteriorated almost beyond recognition.
Lynn Epstein, UC Davis emeritus professor of plant pathology, photographed it under a Leica DVM6 microscope on Nov. 2. An amazing image.
Meanwhile, perhaps the eight monarchs we reared and released made it to an overwintering site along the California coast...maybe to the eucalyptus grove at the Natural Bridges State Park, Santa Cruz.
Or maybe they encountered a predator--a praying mantis or a bird.
Regardless, the declining monarch populations at the overwintering sites along coastal California are troubling.
The Xerces Society for Invertebrate Conservation, based in Portland, Ore., noted in a news release Feb. 2, 2018 that the "annual census of monarch butterflies overwintering along California's coast reveals that populations in western North America are at their lowest point in five years, despite recovery efforts. Volunteers with the Xerces Society's Western Monarch Thanksgiving Count visited more sites this past year than have ever been counted since the survey began in 1997, yet they tallied fewer than 200,000 monarchs."
“This year's numbers indicate a continuing decline in the monarch population,” noted Sarina Jepsen, the Xerces Society's endangered species program director. “Two decades ago, more than 1.2 million monarchs were recorded from far fewer coastal sites, and just last year nearly 300,000 monarchs were observed at almost the same number of sites.” Population estimates at individual sites also suggest that the western monarch population has continued to shrink. Of the 15 sites which have been monitored annually for more than two decades, 11 had lower counts than last year."
Also in the news release, Emma Pelton, conservation biologist with Xerces, said: “Counts at some of the state's largest sites were dramatically lower. Pismo Beach State Park was down by 38 percent, a private site in Big Sur was down by 50 percent, and the Monarch Butterfly Sanctuary in Pacific Grove was down 57 percent, from 17,100 to just 7,350 butterflies.”
Xerces Society officials also noted that "the few sites in which monarch numbers remained stable or increased compared to 2016, include Natural Bridges State Park, Moran Lake, and Lighthouse Field State Park, all in Santa Cruz County."
We like to think that The Vacaville Eight were The Lucky Eight.
"The butterfly counts not months but moments, and has time enough."--Rabindranath Tagore
When we think of orange and autumn, we think of the marriage of the Gulf Fritillary (Agraulis vanillae), and the Mexican sunflower (Tithonia).
The silver-spangled Gulf Fritillary, a showy orange butterfly, looks like two different species. When it spreads its wings, it's orange. The underwings: silver.
"Dazzling," agrees butterfly guru Art Shapiro, UC Davis distinguished professor of evolution and ecology.
"This dazzling bit of the New World Tropics was introduced into southern California in the 19th Century --we don't know how-- and was first recorded in the Bay Area before 1908, though it seems to have become established there only in the 1950s," he says on his website.
"It can be quite common in the East and South Bay --particularly in Berkeley--and has been found breeding spontaneously as far inland as Fairfield where, however, it is not established. There are scattered records in the Central Valley and even up to Folsom, perhaps resulting from people breeding the species for amusement or to release at social occasions."
The Gulf Frit bred in Sacramento in abundance on Passiflora in the early 1960s, Shapiro relates. "It seems to have died out by the early 1970s, however. Intolerant of hard freezes, it still managed to survive the record cold snap of 1990 that largely exterminated the Buckeye regionally!"
Its host plant: Passiflora or passionflower vine. Plant it and they will come (at least in this area)!
"Happiness is a butterfly, which when pursued, is always just beyond your grasp, but which, if you will sit down quietly, may alight upon you."--Nathaniel Hawthorne
It's Halloween and scores of trick-or-treaters are donning monarch butterfly costumes.
But they can't do justice to the living monarchs, those iconic, majestic butterflies that are always dressed in Halloween colors: black and orange.
It's always a treat to see them but they have to avoid the "tricks"--predators and parasitoids.
Among the last monarchs we reared in September: a brightly colored female, healthy and strong and rarin' to go.
Where is she now, on Halloween? Is she overwintering in Santa Cruz or Pacific Grove? Or, did a predator, perhaps a California scrub jay or a praying mantis, nail her?
We don't known "witch" way she went, but as she fluttered away, we wished her "Safe travels!"
It's been a troubling year for monarchs, Danaus plexippus, according to butterfly guru Art Shapiro, UC Davis distinguished professor of evolution and ecology, who maintains a research website, Art's Butterfly World. "I have not seen a wild egg or caterpillar of the monarch this entire calendar year at low elevations," he said Sept. 6, 2018 during an interview on the "Insight with Beth Ruyak" program, Capital Public Radio, Sacramento. "Not one." (Listen to the interview.)
Where to see the overwintering monarchs in California?
They've been found at more than 400 sites along the California coast, according to the Xerces Society for Invertebrate Conservation. "The mild winters of the California coast are a perfect haven from the harsh cold weather found in our country's interior," Xerces says on its website. "Monarchs take advantage of this climate and often use the same overwintering sites year after year. Congregations of overwintering monarchs have been found at more than 400 sites along the California coast, from Mendocino County in the north to San Diego in the south. For many people, the arrival of autumn along the California coast is marked by the flutter of orange and black as monarchs arrive at these groves and settle in for the winter."
"The last few years have witnessed low numbers of butterflies throughout the region compared to the late 1990s, but there are still many places to view overwintering monarchs and get involved!"
But they're not welcome.
Agriculturists who commercially grow cabbage and other cucurbits aren't fond of the cabbage white butterlfy, Pieris rapae, because its larvae are pests that ravish their crops.
No welcome mat for them.
This butterfly, however, is welcome--sort of--starting Jan. 1 of every year in the three-county area of Sacramento, Solano and Yolo. It's the target of the "Beer for a Butterfly Contest," sponsored by Art Shapiro, UC Davis distinguished professor of evolution and ecology. The first one collected in the three-county area collects a pitcher of beer or its equivalent.
Professor Shapiro, who maintains a research website at http://butterfly.ucdavis.edu, launched the contest in 1972 as part of his long-term studies of butterfly life cycles and climate change. Pieris rapae is emerging earlier and earlier as the regional climate has warmed, he says. "The cabbage white is now emerging a week or so earlier on average than it did 30 years ago here."
He usually wins the suds-for-a-bug contest; he has been defeated only four times, and all by UC Davis graduate students. This year (2018) he collected the cabbage white butterfly, Pieris rapae, at 11:23 a.m. Friday, Jan. 19 in one of his frequented sites—a mustard patch by railroad tracks in West Sacramento, Yolo County. (See Bug Squad blog)
Last weekend we spotted a cabbage white nectaring on lantana, a common occurrence. What was not so common was that this one wasn't skittish. It lingered like a ballerina anticipating a curtain call, and allowed us to photograph it in flight.