He not only did--they were the larvae of the common buckeye, Junonia coenia--but this was exciting news--a first-of-its-kind discovery that led to a piece published today (Dec. 13) in the News of the Lepitopterists' Society.
The discovery: The plant is a larval host of the butterfly.
This is the first known case of buckeye larvae feeding on Russelia equisetiformis, an ornamental shrub with red tubular flowers that's widely favored by gardeners and pollinators, including hummingbirds.
The news article, authored by Shapiro and de Grassi, is titled "Buckeye, Junonia coenia, Uses the Garden Ornamental Russellia equisetiforis (Plantaginacease) ("Firecracker Plant") as a Larval Host in California."
As Shapiro explained: The buckeye "oviposits and feeds on a variety of plants that produce iridoid glycosides. The pattern of usage suggests that iridoids are necessary stimulants to oviposition and larval feeding but can be overriden by the presence of other chemicals that act as deterrents. It should not be surprising to find these butterflies using novel hosts that produce iridoids."
Russelia equisetiformis produces a variety of iridoid glycosides, Shapiro says, but up until July 10, there were no previous records of the buckeye feeding on the plant. The colorful plant, native to Mexico and Guatemala, is especially popular in California and the southwestern United States. It is also known by such common names as "fountain bush" and "fountain plant" for its long arching branches. It can reach a height of 4 to 5 feet.
On his Art's Butterfly World website, Shapiro points out that the "buckeye breeds on plants containing bitter iridoid glycosides, including plantains (Plantago, especially P. lanceolata), various Scrophulariaceae (especially Fluellin, Kickxia), and Lippia (Lippia or Phyla nodiflora). The spiny, black-and-white caterpillar has a bright orange head. Its behavior suggests its diet makes it virtually immune to vertebrate predation, but the pupa and adult are quite edible."
Back in 2010, Shapiro and K. Biggs discovered another larval host of the buckeye--an emergent aquatic plant, Hippuris vulgaris, also known as mare's tail or common mare's tail.
As for Russelia equisetiformis, it draws its genus name from Scottish naturalist Alexander Russell (1715-1768). The species name refers to its resemblance to horsetail rushes (the Latin term equisetiformis means "like Equisteum.")
De Grassi, an alumna of UC Davis (bachelor's degree in agricultural science and management, and master's in animal science), said she purchased the plant at a UC Davis Arborteum plant sale when she was transforming her backyard to a "Life without Lawn" project. She was seeking attractive, low-water, long-blooming pollinator plants.
One was a firecracker plant. And along came the buckeyes!
Katie Hetrick, director of Marketing and Communications for the UC Davis Arboretum and Public Garden, wrote about the larval host discovery on the Arboretum website: "It goes to show you that observant home gardeners are important citizen scientists – you never know what discoveries are waiting to present themselves. Now there's yet another reason to love the firecracker plant; not only is it a low-water, long-blooming plant that hummingbirds love, it also appears to be larval host plant for buckeye butterflies!"
As for de Grassi, she continued to see the buckeye caterpillars on her firecracker plant through Aug. 26. And, later, after hearing of her find, Shapiro discovered a female buckeye laying eggs on a firecracker plant by the Sciences Lab Building on the UC Davis campus.
In the piece in News of the Lepitopterists Society, Shapiro wrote that the Russelia equisetiformis "is occasionally cited in horticultural sources as vulnerable to damage by unidentified caterpillars."
Unidentified caterpillars? Mystery solved?
You've probably watched those colorful painted ladies (Vanessa cardui) fluttering about in your yard, but have you read the newly published research about their wing color patterns and genetic codes?
In researching the color patterns and the genes responsible for those patterns, biologists Jeffrey Marcus and Roohollah Abbasi of the University of Manitoba, Winnipeg, Canada, found a previously undetected compartment boundary that may exist in all holometabolous insects. (Holometabolism, also called complete metamorphism, is a form of insect development that includes four stages: egg, larva, pupa and adult.)
Scientists have long known that in the common fruit fly, Drosophila melanogaster, the forewing is divided into two developmental compartments, but this newly published research in Scientific Reports, A New A-P Compartment Boundary and Organizer in Holometabolous Insect Wings, is a real eye-opener.
Writer Viviane Callier of Washington, D.C., a trained insect physiologist, wrote about the research in the Nov. 30th edition of Entomology Today, published by the Entomological Society of America.
In her piece, "Butterfly Color Patterns Reveal Clues About the Genes that Build Insect Wings," Callier described butterfly wings as "natural canvases decorated with elaborate color patterns," but noted that "how these patterns develop and evolve is still incompletely understood. Now, a new study in Scientific Reports (Nature.com) has identified the genetic code by which butterflies can assign color patterns to different parts of their wings during development. The code is based on a set of genes called transcription factors that establish compartments in most—perhaps all—insect wings. Each compartment, whose 'address' is determined by the combination of genes that are active in that sector of the wing, can evolve different color patterns independently from the other compartments."
Marcus and Abbasi explained in their abstract:
"Decades of research on the highly modified wings of Drosophila melanogaster has suggested that insect wings are divided into two Anterior-Posterior (A-P) compartments separated by an axis of symmetry. This axis of symmetry is created by a developmental organizer that establishes symmetrical patterns of gene expression that in turn pattern the A-P axis of the wing. Butterflies possess more typical insect wings and butterfly wing colour patterns provide many landmarks for studies of wing structure and development. Using eyespot colour pattern variation in Vanessa butterflies, here we show an additional A-P axis of symmetry running between wing sectors 3 and 4. Boundaries of Drosophila mitotic clones suggest the existence of a previously undetected Far-Posterior (F-P) compartment boundary that coincides with this additional A-P axis. A similar compartment boundary is evident in butterfly mosaic gynandromorphs. We suggest that this additional compartment boundary and its associated developmental organizer create an axis of wing colour pattern symmetry and a gene expression-based combinatorial code, permitting each insect wing compartment to acquire a unique identity and allowing for the individuation of butterfly eyespots."
The research "bears on some of our T-shock experiments back in the 70s-80s," observed Art Shapiro, distinguished professor of evolution and ecology when asked if he'd read the research paper. Yes. He wrote a chapter, The Genetics of Seasonal Polyphenism and the Evolution of 'General Purpose Genotypes' in Butterflies' in the Klaus Wöhrmann/Volker Loeschcke book, Population Biology and Evolution. You can read it online.
In his abstract, Shapiro, who has studied and monitored butterflies for more than four decades and maintains a website, Art's Butterfly World, points out that his Genetics of Seasonal Polyphenism chapter "is really a specialized appendix to Professor Scharloo's on 'The Genetics of Adaptive Reactions.' It deals with a particular set of such reactions — those of butterfly wing patterns to environmental factors — and asks whether those which seem adaptive are evolutionarily related to those which do not, and if so, how. Despite more than a century of interest in such phenomena, the answers are not yet in; we are only now able to do the carefully controlled experiments necessary to partition phenotypic variation into its environmental and genetic components and this work is still very much in progress. So this will be a very unsatisfying presentation — full of qualitative statements, long on speculation, short on hard data. If it serves as a provocation it will have done its duty."
Shapiro goes on to say that "a glance through any butterfly book of the coffee table variety reveals an astonishing diversity of patterns. The fact is that we have only the remotest idea of the functional significance of any of them, as we were recently reminded by Silberglied et al. (1980). One reason is that bewildering diversity which defies rational classification; another is that it is almost impossible to relate a pattern to an ecological and behavioral context when observing a specimen set on a pin."
All the more reason to marvel at the stunning diversity of butterflies that grace our yards. Or what Viviane Callier so eloquently described as "natural canvases decorated with elaborate color patterns."
So there they were, the bride and groom, culminating their vows.
We spotted them in Vacaville, Calif., clinging to a passion flower vine (Passiflora), their host plant--just the two of them, the female Gulf Fritillary (Agraulis vanillae) and the male.
Two's company? Not for long.
Soon other Gulf Frits descended on them.
Two's company, three's a crowd. Where did all those uninvited guests come from? They're everywhere!
All went well, though. The guests fluttered off, leaving the couple alone and allowing the photographer to engage in insect wedding photography.
Gulf Frits are incredibly beautiful, what with their bright orange wings with black markings, and underside, their elongated silver iridescence spots. A touch of the tropics!
Gulf Frits have been around a long time in the Bay Area--more than a century, according to Art Shapiro, distinguished professor of evolution and ecology at UC Davis. "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," Shapiro writes 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. According to Hal Michael, who grew up in South Sacramento, this species bred there in abundance on garden Passiflora in the early 1960s. 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!"
Shapiro says that in the Bay Area "this species can be seen flying any day of the year, if it is warm and sunny enough."
Thankfully, that's not all they do.
Coming soon to a passion flower vine near you--eggs, caterpillars, chrysalids, and then those gorgeous butterflies!
A Sept. 7 article in Reuters, headlined "Monarchs in Western United States Risk Extinction, Scientists Say," indicated that "Monarch butterflies west of the Rocky Mountains are teetering on the edge of extinction, with the number wintering in California down more than 90 percent from the 1980s, researchers said in a study published on Thursday."
Reuters' reporter Laura Zuckerman wrote that "The migratory monarchs of the western United States have a 63 percent chance of extinction in 20 years and an 84 percent chance in 50 years if current trends continue, according to the study."
The scientists, led by Washington State University conservation biologist Cheryl Schultz, published their work in the journal Biological Conservation. It was funded by the U.S. Fish and Wildlife Service, which is weighing the prospect of offering federal protection for monarch butterflies through the Endangered Species Act. The Xerces Society for Invertebrate Conservation is among those spearheading the effort.
Noted lepidopterist Arthur Shapiro, UC Davis distinguished professor of evolution and ecology who has studied butterflies, including the monarchs, for more than four decades, doubts that the western monarchs are teetering on the edge of extinction.
Shapiro, who maintains a website, Art's Butterfly World. says that yes, the western monarchs have been declining faster than the eastern monarchs, as per the Biological Conservation paper. However, during the drought, California populations appeared to rebound significantly, and it is not known whether the trend will persist, he says.
Their comprehensive and well-researched work, titled "Understanding a Migratory Species in a Changing World: Climatic Effects and Demographic Declines in the Western Monarch Revealed by Four Decades of Intensive Monitoring," was funded in part by the National Science Foundation. Their Oecologia abstract: "Migratory animals pose unique challenges for conservation biologists, and we have much to learn about how migratory species respond to drivers of global change. Research has cast doubt on the stability of the eastern monarch butterfly (Danaus plexippus) population in North America, but the western monarchs have not been as intensively examined. Using a Bayesia hierarchial model, sightings of western monarchs over approximately 40 years were investigated using summer flight records from ten sites along an elevational transect in Northern California."
"Multiple weather variable were examined, including local and regional temperature and precipitation. Population trends from the ten focal sites and a subset of western overwintering sites were compared to summer and overwintering data from the eastern migration. Records showed western overwintering grounds and western breeding grounds had negative trends over time, with declines concentrated early in the breeding season, which were potentially more severe than in the eastern population."
"Temporal variation in the western monarch also appears to be largely independent of (uncorrelated with) the dynamics in the east. For our focal sits, warmer temperatures had positive effect during spring. These climatic associations add to our understanding of biotic-abiotic interactions in a migratory butterfly, but shifting climatic conditions do not explain the overall, long-term, negative population trajectory observed in our data."
In acknowledgments, Shapiro and his colleagues thanked the Xerces Society for Invertebrate Conservation and the North American Butterfly Association for the monarch counts and making the data publicly available.
Meanwhile, since late August, the western monarchs (Arizona, California, Nevada, Oregon, Washington, Idaho and Utah) have been winging their way to their overwintering spots to forested groves along coastal California.
And then, around February, they will head inland to start the process again.
It's an amazing phenomenon.
As I write this, four monarchs are gathering some flight fuel, nectaring from two M's: milkweed and Mexican sunflower in our little pollinator garden in Vacaville, Calif., part of their migratory path to the coast. They flutter from flower to flower, seemingly unaware of the California scrub jay circling them and a photographer zeroing in on them. Or the rain about to fall.
It's National Pollinator Week!
Do you know where your pollinators are?
Or better yet, do you know how to attract them and protect them?
Pollinator Partnership has announced that June 19-25 has been designated National Pollinator Week by the U.S. Department of Agriculture and the U.S. Department of the Interior.
Talk about alliteration: pollinators can be bees, birds, butterflies, bats and beetles. (And many other species, including flies.)
We stepped into our pollinator garden this morning (before the heat shot up to 107 degrees) to check for butterfly diversity.
- A Gulf Fritillary, Agraulis vanillae, flutter over to the pink mallow.
- A mournful duskywing, Erynnis tristis,warm itself on the butterfly bush.
- And a cabbage white butterfly, Pieris rapae, linger on the lavender.
They're all pollinators.
Of course, the larvae of the cabbage white is considered a pest (see UC Statewide Integrated Pest Management website), but the adult looks like a lady in white.
The adult cabbage white butterfly can yield you a prize--a pitcher of beer or its equivalent--if you collect the first one of the year in the annual Beer-for-a-Butterfly Contest, hosted by Art Shapiro, UC Davis distinguished professor of evolution and ecology. The bug must be collected in the three-county area of Solano, Yolo or Sacramento.
Shapiro, who has studied butterflies of Central California for more than four decades and posts research information on his website, usually wins. Read why he sponsors the contest and where he found the first one of 2017 on Bug Squad.