- Author: Kathy Keatley Garvey
Who doesn't love jumping spiders?
They're adorable. No? Well, they are to arthropod enthusiasts, but not so much to their prey.
This one (probably a Phidippus audax, a Bold Jumper) was moving slowly and unobtrusively up a shadowed Vacaville stucco wall on the morning of Jan. 2.
It may have been hunting for prey or simply seeking some sun.
The jumping spider, family Salticidae, is a thing of beauty, but to some folks it's a thing of fright.
Did you catch science writer James Gorman's article on How the Jumping Spider Sees Its Prey in the Nov. 6, 2018 edition of The New York Times?
"If you love spiders, you will really love jumping spiders," Gordon began, humorously adding that "If you hate spiders, try reading this article on dandelions."
"O.K., if you're still here, jumping spiders are predators that stalk their prey and leap on them, like a cat. They are smart, agile and have terrific eyesight."
Gorman pointed out that "It has been clear for a long time that their vision is critical to the way they hunt, and to the accuracy of their leaps. But a lot has remained unknown about the way their eyes work together." He then detailed the newly published research on spider vision by Elizabeth Jakob of the University of Massachusetts and her colleagues.
"Jumping spiders have eight eyes," Gorman gently reminded his readers (who were probably already reading about dandelions). "Two big eyes, right in the center of what you might call the spider's forehead, are the principal ones, and they pick up detail and color. Of the other three pairs, a rear set looks backward, a middle set is as yet a bit of a mystery, and the foremost detect motion."
The spider we saw on the stucco wall certainly detected our motion.
Somewhat like the phrase attributed to Julius Cesar's "I came, I saw, I conquered," our spider "came, jumped and vanished."
Goodbye, spider.
And no, I'm not going to read that article on dandelions.
- Author: Kathy Keatley Garvey
The painted ladies are on the move.
Have you seen these migratory butterflies, Vanessa cardui, passing through California on their way to the Pacific Northwest?
Me? No! Zero. Zilch. Zip.
But butterfly guru Art Shapiro, distinguished professor of evolution and ecology, who has monitored the butterfly population of Central California for more than four decades and maintains a research website, has seen approximately 400 painted ladies this season--about 300 today.
All I saw today was a lone cabbage white butterfly flying through our pollinator garden in Vacaville.
Guess the painted ladies didn't get the message. The New York Times, did, though.
"The orange butterflies, called painted ladies, are known to travel annually from the deserts of Southern California to the Pacific Northwest," wrote New York Times reporter Julia Jacobs in a March 17th piece. "This month, people are taking notice because of the sheer size of the migration: Scientists estimate the teeming painted ladies number in the millions."
"Substantial rainfall in the deserts near the Mexican border, where the North American painted ladies lay their eggs, is the reason for the unusually large swarms," Jacobs pointed out. "The rain caused plants to thrive, giving the painted lady caterpillars plenty of food to fuel their transformation, said Art Shapiro, a professor of evolution and ecology at the University of California, Davis."
Shapiro told the New York Times that "the striking thing is they're moving very rapidly and directionally. So it's almost like being in a hail of bullets.”
They're passing through Davis, too. Shapiro headed over to the UC Davis Memorial Union patio today and noticed that "the painted ladies are on the upswing. Many are nectaring, suggesting they're running out of fat, but despite the abundance of potential hosts, saw no oviposiiton. Condition extremely variable, from beat-to-hell to looking almost fresh."
The professor witnessed them passing by the Memorial Union "roughly one every 90 seconds." Ironically, no one seemed to notice them, Shapiro said. Well, it is finals week!
The Los Angeles Times reported March 11 that a "massive swarm of at least 1 billion butterflies is traveling across Los Angeles and neighboring counties at a breathtaking speed of almost 20 miles an hour." They're in a "rush to reach their breeding areas in Oregon."
Shapiro says that years of tremendous wildflower blooms are typically big years for the butterflies. The last big year was 2005. He explains the phenonomen on his website:
"This mass-migrant occurs in much of the Northern Hemisphere. 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. 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, but how can we know? At Sacramento at the height of the migration butterflies were passing in one's field of vision at the rate of about 3 per second! 2006, by contrast, was a La Nina year with very little rain in the desert. The butterflies apparently gave up trying to breed there and flew north in February. They tried to breed but mostly were unsuccessful due to bad weather, resulting in only very sporadic individual sightings of their progeny in May.
"Northward-migrating Painted Ladies are provisioned with yellow fat and are reproductively immature," he writes. "They do not stop to feed or have sex until they have burned up their reserves, carried over from the caterpillar stage. 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."
Well, maybe tomorrow one or more painted ladies will fly my way. Preferably more.
Shapiro just received word of "a major movement through the Kern River Valley. Inyo-Kern is the superhighway from the desert to the Central Valley, so the biggest numbers may yet be on the way."
- Author: Kathy Keatley Garvey
Totally fascinating.
Tsetse fly expert Geoffrey Attardo, a medical entomologist and assistant professor with the UC Davis Department of Entomology and Nematology, drew the attention of Pulitzer-Prize winning science writer Natalie Angier who penned the article, "Everywhere in the Animal Kingdom, Followers of the Milky Way" (subhead: "As scientists learn more about milk's evolution and compositional variations, they are redefining what used to be a signature characteristic of mammals.")
Her lede: "Most female flies take a low-rent approach to parenthood, depositing scores of seed-sized eggs in the trash or on pet scat to hatch, leaving the larvae to fend for themselves."
"Not so the female tsetse fly. She gestates her young internally, one at a time, and gives birth to them live. When each extravagantly pampered offspring pulls free of her uterus after nine days, fly mother and child are pretty much the same size."
Then she quoted the UC Davis medical entomologist:
“It's the equivalent of giving birth to an 18-year-old,” said Geoffrey Attardo, an entomologist who studies tsetse flies at the University of California, Davis.
Attardo focuses his research on numerous aspects of the physiology of tsetse fly reproduction, with the goal to identify and understand key aspects of its reproductive biology. He joined the UC Davis Department of Entomology and Nematology in 2017 from tje Yale University School of Public Health, New Haven, Conn., where he researched tsetse flies in the lab of Serap Aksoy.
In terms of "fascinating physiological adaptations," Attardo considers the tsetse fly "one of the champions of the insect world!" As he explained to us in a 2017 news story: "In addition to being vectors of a deadly disease, Trypanosomiasis, these flies have undergone amazing alterations to their physiology relative to other insects. Some examples of this are their ability feed exclusively on blood, their obligate relationship with a bacterial symbiont, the fact that they lactate and that they give birth to fully developed larval offspring."
"The opportunity to study the adaptations these flies have made is like opening a toy chest for an insect physiologist. My work in tsetse has focused on the molecular biology underlying the adaptations associated with the development of lactation, symbiosis, male and female mating interactions/physiology and nutrient metabolism and mobilization.”
Attardo's published research is drawing national and international attention, as are his incredible images of tsetse flies. He won the 2010 Fogarty Grantee Photo Contest with an image of a tsetse fly. The Yale School of Public Health magazine featured his images on “An Eye for the Tsetse Fly.” The Los Angeles Times published his remarkable video (in 2014) of a tsetse fly giving birth. Also, see his portraits of the tsetse fly on Live Science, published in 2014.
In her New York Times article, Angier points out that "Only in the class Mammalia do all member species nurse their young, yet evolutionary biologists now believe that the roots of mammalian lactation date back more than 300 million years, a good 100 million years before the first mammals appeared."
Who knew?
And while on the subject of tsetse flies, be sure to read the September 2016 article, "Tsetse Flies Are Strange and Dangerous," by Kevin Fitzgerald in Entomology Today, a publication of the Entomological Society of America. Fitzgerald featured the work of Attardo and posted one of his photos.
- Author: Kathy Keatley Garvey
He sounded the alarm.
“We need 1.6 million colonies, or two colonies per acre, and California has only about 500,000 colonies that can be used for that purpose,” said Mussen in a news release we posted Feb. 8 on the Department of Entomology website. “We need to bring in a million more colonies but due to the winter losses, we may not have enough bees.”
Those winter losses--still being tabulated--and the resulting fewer bees per hive could spell trouble for almond growers, he said.
He said 2012 was a bad year for bee nutrition.
“Last year was not a good year for honey production in the United States,” Mussen said, “and it could be one of the worst honey production years in the history of nation, although it’s been pretty rough in some of the previous years. Usually when we’re short of nectar, we’re short on pollen, and honey bees need both. So, 2012 was a bad year for bee nutrition.”
The winter of 2012-2013, in general, was bad for bees. In fact, it's never been good since the winter of 2006 with the onset of colony collapse disorder, a mysterious malady characterized by adult bees abandoning the hive, leaving behind the queen bee, brood and food stores.
Bee scientists think CCD is caused by a multitude of factors, includes, pests, pesticides, parasites, diseases, malnutrition and stress. On the average, beekeepers report they're losing one-third of their bees a year.
“We don’t know how many more bees will be lost over the winter,” Mussen told us on Feb. 8. “We consider the winter ending when the weather warms up and the pollen is being brought into the hives.”
“Many, many colonies are not going to make it through the winter. We won’t have as large a bee population as in the past.”
Mussen, a member of the UC Davis Department of Entomology since 1976, knows honey bees. He is a honey bee guru, a global expert on bees. "Have a question about bees? Ask Eric Mussen." This month, especially, he is in great demand as a news source.
The New York Times quoted Mussen in its March 28th article, "Mystery Malady Kills More Bees, Heightening Worry on Farms."
Eric Mussen, an apiculturist at the University of California, Davis, said analysts had documented about 150 chemical residues in pollen and wax gathered from beehives.
"Where do you start?" Dr. Mussen said. "When you have all these chemicals at a sublethal leel how do they react with each other? What are the consequences?"
Experts say nobody knows.
Meanwhile, Mussen spent much of the day today granting news media interviews. On Tuesday, April 2, it will be for Dan Rather Reports: Buzzkill.
It was not so long ago that honey bees drew little attention, despite the fact that they pollinate about one-third of the food we eat. A three-letter acronym, CCD, changed all that.
Rich Schubert, a beekeeper in the Winters/Vacaville area, said it best during a question-and-answer session at Mussen's UC Davis Distinguished Seminar on Oct. 9, 2007.
If 5600 dead cows were found in a pasture, instead of 5600 dead bees, people would start paying attention, Schubert told the crowd.
So true. And now they are.
- Author: Kathy Keatley Garvey
“If you were an aphid on a head of lettuce, a hoverfly larva would be a nightmare. They are voracious eaters of aphids. One larva per plant will control the aphids.”
That's what organic researcher Eric Brennan of the Agricultural Research Service (ARS), U.S. Department of Agriculture, told reporter Jim Robbins in a recently published New York Times article.
Headlined "Farmers Find Organic Arsenal to Wage Wars on Pests," the news story drew attention to why natural enemies are "key to the organic approach."
Brennan is based in Salinas Valley, known as "The Salad Bowl of America." It's reportedly where 80 percent of Americans get their greens.
And it's where the lettuce aphid gets its lettuce.
To help resolve the problem, organic farmers are planting alyssum in their lettuce beds. Hover flies "live in the alyssum and need a source of aphids to feed their young, so they lay their eggs in the lettuce," Robbins wrote. "When they hatch, the larvae start preying on the aphids."
Could be that the "salad days" are over for the aphids--thanks to Brennan, alyssum and hover flies.
