- Author: Kathy Keatley Garvey
Ever seen a lagoon fly?
It's a syrphid fly, Eristalinus aeneus, distinguished by small black spots patterning its eyes. Syrphids, also known hoverflies or flower flies, hover over a flower before foraging. They're pollinators.
Native to Europe and widespread throughout Europe and the United States, it draws its common name from its habitat of lagoons, ponds, slow-moving rivers, streams and irrigation ditches.
This little pollinator (below) took a liking to our Virginia stock (Malcolmia maritima). It competed with a few honey bees, but kept low.
The lagoon fly is a common research subject. Recently a team of international researchers (University of Wisconsin, Sweden, Australia and India) published their work, "Innate Floral Object Identification in the Generalist Solitary Hoverfly Pollinator Eristalinus aeneus," in BioRxiv, the preprint server for biology.
The abstract:
"All animals must locate and identify food for their survival. Most insects are solitary. Newly emerged solitary insects must therefore employ innate identification of food cues to locate relevant nutritive objects from a distance. Innate preferences for food cues should be both specific enough to allow discrimination between food and non-food objects and general enough to allow for the variety of food objects relevant to each species' ecology. How insects with small nervous systems are able to encode these cues innately is an area of intense study for ecologists and neuroscientists alike. Here, we used the solitary generalist pollinator Eristalinus aeneus to understand how the innate search template used to identify multiple floral species can arise through a small number of sensory cues spanning multiple modalities. We found that innate floral choices of the hoverfly E. aeneus are a product of contextual integration of broad, plant-based olfactory cues and visual cues, where a combination of radial symmetry and reflection in the 500-700 nm wavelength range was particularly important. Our study, therefore, shows how tiny brains can efficiently encode multimodal cues to identify multiple relevant objects without prior experience."
The research originates from The NICE Lab, which stands for Naturalist-Inspired Chemical Ecology (corresponding authors: Aditi Mishra, at aditi@nicelab.science, and Shannon Olson at shannon@nicelab.science).
You got to love the NICE website: "We are creative, dedicated, and adventurous. We are NICE." And when they recruit they ask "Are you NICE?"
- Author: Kathy Keatley Garvey
If you've been pruning bushes or trees, check to see if a praying mantis egg case (ootheca) is attached to a limb.
If you do, you're in luck!
A mantis deposits her egg case in late summer or fall, and usually on twigs, stems, a wooden stake or fence slat, but sometimes even on a clothespin.
The nymphs emerge in early spring.
The hard egg capsule protects the future offspring from "microorganisms, parasitoids, predators, and weather," Wikipedia tells us. The ootheca "maintains a stable water balance through variation in its surface, as it is porous in dry climates to protect against desiccation, and smooth in wet climates to protect against oversaturation. Its composition and appearance vary depending on species and environment."
Meanwhile we've been watching a neighbor's gift: an ootheca attached to redbud twig. With any luck, we expect the nymphs to emerge around April 9, weather permitting.
Back in 2022--April 9th to be exact--we were delighted to see some 150 nymphs emerge from the clothespin just a'hanging on the line. Of course, the sisters and brothers ate one another. Only a handful survived.
It's survival of the fittest. Or the fleetist. Or maybe just luck?
- Author: Kathy Keatley Garvey
A gray butterfly and a fruit fly...
Each has "fly" in its name but one is a member of the order Lepidoptera and the other, order Diptera. Etymology does not agree with entomology.
Ever managed to photograph a butterfly and fruit fly in the same image?
Presenting: a gray hairstreak butterfly, Strymon melinus, and a fruit fly, Neotephritis finalis, an organism commonly known as "the sunflower seed maggot."
They were foraging March 21 in a Vacaville garden on Coreopsis, a genus of flowering plants in Asteraceae.
N. finalis, one of the most commonly seen fruit flies (tephritids) flies in North America. develops in the seed heads of plants in the sunflower family. They're also called "picture-winged flies." BugGuide.net tells us "Wings are mostly dark in apical half with six hyaline spots forming a distinct triangle."
The wings are indeed striking!
But so are the wings of the gray hairstreak butterfly. That orange spot with a black dot on the hindwing probably resembles an eye to a predator.
Butterfly guru Art Shapiro, UC Davis distinguished professor emeritus, says on his research website that the gray hairstreak "is one of the most polyphagous butterflies known, recorded on host plants in many families. Its most frequent hosts in our area are mallows, including the weedy species of Malva; legumes, including Spanish Lotus (Lotus purshianus), Bird's-Foot Trefoil (Lotus corniculatus), White Clover (Trifolium repens) in lawns, Alfalfa (Medicago sativa) and many others; and Turkey Mullein (Eremocarpus or Croton setigerus, Euphorbiaceae)."
Maybe we'll see the butterfly and the fruit fly again...
- Author: Kathy Keatley Garvey
Today's Honorary Bee Image Award goes to...drum roll...an image of a humble hoverfly appearing on the National Geographic Facebook page.
The caption reads "A bee sits on a marigold flower in Coronado National Forest, Arizona, USA."
Bee? Umm, no!
Marigold? Umm, no!
Sits? A bee does what?
Hey, hoverfly, you're an honorary bee!
Indeed, why can't the hoverfly, aka syrphid fly or flower fly, gain a little stature?
As of 3 p.m. today, this mistaken-identity image has drawn 2,400 views, 66 comments and 136 shares from National Geographic's 50 million FB followers.
It's a beautiful insect image by freelance photographer David Littschwacher. Who wrote the caption? Not an entomologist. Ironically, however, numerous National Geographic followers are unaware of the faux paux. A sprinkling of the comments:
- "Beautiful picture"
- "Very nice photo; spring brings lots of flowers"
- "A beautiful sight!"
- "Our nature...priceless"
- "Nature's delicate balance beautifully displayed in Coronado National Forest, Arizona, USA."
- "You might want to check your identification on both plant and insect"
- "Not a bee but a hoverfly"
- "That bee is a species of hoverfly, absolutely surprised at you, of all organizations"
- "Leave it to NatGeo…"
- "You would think Nat Geo could identify a bee, instead of a fly! Lesson for people that trust anything on social media, especially pictures"
- "Not on a marigold, either"
- "Looks more like a fly...National Geographic--do your research!"
With so much misinformation and disinformation spreading globally, even the humble hoverfly gets into the act!
Probably one of the most embarrassing mistakes, though, is that dratted fly on the cover of Bees of the World, authored by noted hymenopterists Christopher O'Toole and Anthony Raw.
Syrphid flies (order Diptera) are easily distinguished from honey bees (order Hymenoptera). Among the key differences: (1) syrphids have only one pair of wings, while honey bees have two (2) syrphids have short, stubby antennae, while honey bees have long, bent antennae called genticulate antennae and (3) syrphids have large, wrap-around eyes and honey bees do not.
And if you watch them in action, a hoverfly will hover over a flower before touching down (thus the name). A honey bee is more directional in her flight pattern as she buzzes in to forage on a flower.
Some hoverflies mimic the coloration of bees and wasps, gaining a little protection from predators. Unlike bees, however, hoverflies don't sting.
But cheers, both are pollinators!
- Author: Kathy Keatley Garvey
You'll learn which butterfly populations are struggling and which ones are doing well, and glean more information about the research of UC Davis distinguished professor emeritus Art Shapiro, and his collaborator, Professor Matt Forister of the University of Nevada, his former doctoral student.
Shapiro has been monitoring the butterfly populations of central California since 1972. His transect of ten fixed study sites sprawls from the Sacramento River Delta, through the Sacramento Valley and Sierra Nevada mountains, and to the high desert of the western Great Basin. The sites, Shapiro says, "represent the great biological, geological, and climatological diversity of central California."
The article is authored by entomologist Mary Louise Flint, a docent at the center and editor of the quarterly. She holds the title of professor of Cooperative Extension emerita, based in the UC Davis Department of Entomology and Nematology. She served as a longtime associate director of the UC Statewide Integrated Pest Management Program (UC IPM) until her retirement in June 2014. (See her biography on the UC IPM website).
"Over the last decade or two, scientists in many parts of the world have documented examples of declining insect num- bers—both in numbers of species (species richness) and in the number of individuals of each species (population levels)," Flint began. "Habitat loss, pesticide use, and climate change are usually identified as the main contributing factors, although circumstances vary among insect species and location."
"Three of Shapiro's sample sites," Flint pointed out, "are relatively close to our nature area—Rancho Cordova, near the American River across from Sacramento Bar, North Sacramento on the American River near California State University, and West Sacramento in the Yolo Bypass near the causeway. (The Rancho Cordova site is closest and most similar to Effie Yeaw in habitat.) A close study of the data collected at these sites between 1988 and 2010 showed that summer minimum temperatures and fall maximum temperatures increased significantly and precipitation decreased. During this time, species richness tended to decrease after years of high temperatures and reduced precipitation."
Among those on "the struggling list" are the monarch, Danaus plexippus; West Coast lady, Vanessa annabella; the great copper, Lycaena xanthoides; and the large marble, Euchloe ausonides. The large marble, "formerly common in the Central Valley, Delta, Bay Area and lower foothills...has suffered an unexplained crash and is teetering on the brink of regional extinction," according to Shapiro's website.
Those on the "doing well" list include the Gulf Fritillary, Agraulis vanillae; pipevine swallowtail, Battus philenor; fiery skipper, Hylephila phyleus; the Western tiger swallowtail, Papilio rutulus; and the gray hairstreak, Strymon melinus.
See Flint's article for more information, and access Shapiro's research research website, and Forister's research website.
A buckeye butterfly, Junonia coenia (image by yours truly) graces the cover. Numerous other butterfly images illustrate the piece.
Shapiro recently delivered a presentation, "Using Butterflies to Understand Biotic Responses to Climate Change," at the UC Davis emeriti celebration, organized and coordinated by UC Davis Distinguished Professor Walter Leal of the Department of Molecular and Cellular Biology. (See Shapiro's presentation on YouTube and coverage on Bug Squad blog.)