- Author: Kathy Keatley Garvey
In stunning images, the Bohart Museum display depicts the complete metamorphosis of the monarch: from egg to larva to pupa to adult.
It's the work of Larry Snyder of Davis, who for several years photographed a UC Davis professor's research project on wild monarch-native milkweed interactions in the North Davis Channel of rural Davis. Snyder is a retired music teacher, vocal accompanist, and piano and harpsichord technician.
We wrote about the monarch-milkweed project on the UC Davis Department of Entomology and Nematology website on July 28, 2022.
Professor Louie Yang, the principal investigator of the research project, organized and led a 135-member team, all co-authors of the paper, “Different Factors Limit Early- and Late-Season Windows of Opportunity for Monarch Development,” published in the journal Ecology and Evolution. (This document is open access at https://bit.ly/3volFaI.)
From 2015 through 2017, the team monitored the interactions of monarchs, Danaus plexippus, on narrow-leafed milkweed, Asclepias fascicularis, planted in December 2013 on city-owned property adjacent to the North Davis irrigation channel.
The project, funded by two of Yang's National Science Foundation grants, involved UC Davis, Davis Senior High School and the Center for Land-Based learning. Among them were 107 high school students and a K-12 teacher, 18 UC Davis undergraduate students, three graduate students and two post-graduate researchers.
Unfortunately, a City of Davis maintenance crew unintentionally mowed the site on May 5, 2017, “damaging several plants in this population," Yang related. "However, most plants in the population were below the height of the mower blades at this point in the growing season.”
Today the milkweed population at the North Davis Channel is being maintained by the City of Davis and dedicated citizens, including Larry Snyder.
From music to milkweed to monarchs...it's been quite a journey.
The work of Professor Yang's MMMILC crew fascinated him, and the site became his "adopted back yard." At first, Snyder just watched, then he began photographing "the insect life on the plants." At the end of the project's official monitoring period, he "secured the cooperation of city staff" so he could continue maintaining the milkweeds without the loss of spring growth to the annual fire-suppression mowings.
Snyder says he "especially enjoys watching insect behavior and interaction, both within and between species and in relation to the host plants, as well as tracking how individual populations change during the seasons and from year to year."
"I am most grateful to the Bohart Museum and the frequent assistance of their remarkable staff and associates," Snyder said.
The Bohart Museum, founded in 1946, is directed by Lynn Kimsey, UC Davis distinguished professor of entomology. It is the global home of eight million insect specimens, as well as the live "petting zoo" and an insect-themed gift shop stocked with t-shirts, hoodies, books, posters, jewelry, collecting equipment and more. Named for UC Davis professor and noted entomologist Richard Bohart, it is open to the public from 8 a.m. to noon, and 1 to 5 p.m., Mondays through Thursdays. More information is available on the website at https://bohart.ucdavis.edu or by contacting bmuseum@ucdavis.edu.
/span>- Author: Kathy Keatley Garvey
It's early morning, Aug. 20. A lady beetle is snacking on aphids on our native milkweed plant (where the monarchs are supposed to be, but aren't!). And then, apparently satiated, LB climbs a twig to the top of her Mt. Everest, looks around, unfolds her wings, and takes off.
The miracle of flight! The miracle of unpacking what's under those wings. The miracle of seeing it all happen.
"The ladybug is a tiny insect with hind wings four times its size," wrote Joanna Klein in her article,
Ladybugs Pack Wings and Engineering Secrets in Tidy Origami Packages, in the May 18, 2017 edition of The New York Times. "Like an origami master, it folds them up into a neat package, tucking them away within a slender sliver of space between its abdomen and the usually polka-dotted, harder wings that protect it.
"When it is time to take off, it deploys its flying apparatus from beneath its colorful shell-like top wings, called the elytra, in only a tenth of a second. And when it lands, it folds it back in just two. Switching between flying and crawling many times in a day, the ladybug travels vast distances."
Klein called attention to a study published in the May 17, 2017 edition of the Proceedings of the National Academy of Sciences. The authors, she said, detailed "just how the ladybug manages to cram these rigid structures into tiny spaces is a valuable lesson for engineers designing deployable structures like umbrellas and satellites."
It's the work of Kazuya Saito of the Institute of Industrial Science, University of Tokyo, Japan, and his colleagues, Shuhei Nomura, Shuhei Yamamoto, Ryuma Niiyama and Yoji Okabe.
The title? "Investigation of Hindwing Folding in Ladybird Beetles by Artificial Elytron Transplantation and Microcomputed Tomography."
The significance? "Hindwings in ladybird beetles successfully achieve compatibility between the deformability (instability) required for wing folding and strength property (stability) required for flying. This study demonstrates how ladybird beetles address these two conflicting requirements by an unprecedented technique using artificial wings. Our results, which clarify the detailed wing-folding process and reveal the supporting structures, provide indispensable initial knowledge for revealing this naturally evolved optimization system. Investigating the characteristics in the venations and crease patterns revealed in this study could provide an innovative designing method, enabling the integration of structural stability and deformability, and thus could have a considerable impact on engineering science."
The abstract? "Ladybird beetles are high-mobility insects and explore broad areas by switching between walking and flying. Their excellent wing transformation systems enabling this lifestyle are expected to provide large potential for engineering applications. However, the mechanism behind the folding of their hindwings remains unclear. The reason is that ladybird beetles close the elytra ahead of wing folding, preventing the observation of detailed processes occurring under the elytra. In the present study, artificial transparent elytra were transplanted on living ladybird beetles, thereby enabling us to observe the detailed wing-folding processes. The result revealed that in addition to the abdominal movements mentioned in previous studies, the edge and ventral surface of the elytra, as well as characteristic shaped veins, play important roles in wing folding. The structures of the wing frames enabling this folding process and detailed 3D shape of the hindwing were investigated using microcomputed tomography. The results showed that the tape spring-like elastic frame plays an important role in the wing transformation mechanism. Compared with other beetles, hindwings in ladybird beetles are characterized by two seemingly incompatible properties: (i) the wing rigidity with relatively thick veins and (ii) the compactness in stored shapes with complex crease patterns. The detailed wing-folding process revealed in this study is expected to facilitate understanding of the naturally optimized system in this excellent deployable structure."
But back to our little lady beetle in our pollinator garden. It's difficult to catch a lady beetle in flight. They don't fly when you WANT them to, and when they do fly, you and your camera are NOT ready. And when you and your camera ARE ready, all focused and everything, they change their mind or change directions. So, in keeping with our motto, "Don't poke 'em, prod 'em or pin 'em," we waited.
With the morning sun behind her back, LB finally obliged and took flight.
We managed to catch the action with a Nikon Z7 with a Nikon 105mm lens, manually focused: F-stop 16; shutter speed, 1/2500 of a second; and ISO, 5600.
Here's hoping LB will return. She missed a few aphids!
- Author: Kathy Keatley Garvey
The narrowleafed milkweed, Asclepias fascicularis, beckons monarch butterflies (the host plant), aphids, praying mantids and assorted other insects, but once in a while, you'll see a leafcutter bee. Both the plant and the bee are natives.
This male bee (below) spent the afternoon patrolling for females, but it rested in between.
It's a dangerous place to rest when there's a predator (praying mantis) around, but all ended well.
Leafcutter bees, spp., so named because the females cut leaves and petals (perfectly round holes!) to line their nests, are smaller than honey bees--and much faster. They're easily recognizable by the black-white bands on their abdomen.
The females do all the work. They gather pollen and nectar, make the nests from the leaf and petal fragments, and lay eggs. They seal the egg chambers with the leaves or flower petals.
The male's job is to reproduce. And sometimes, you'll see one sunning itself on a milkweed leaf.
Of the 4000 bee species known in the United States, about 1600 reside in California. The leafcutter bee is just one of them. The family, Megachilidae, includes these leafcutting bees, Megachile angelarum, M. fidelis and M. montivaga; the alfalfa leafcutting bee, M. rotundata; the Mason bee, Osmia coloradensis; and the blue orchard bee (BOB), Osmia lignaria propinqua.
For more information on California's bees, read California Bees and Blooms: A Guide for Gardeners and Naturalists (Heyday), the work of UC-affiliated scientists,
/span>- Author: Kathy Keatley Garvey
She came, she saw, she oviposited, she nectared and she left.
That's the extent of our sole monarch sighting in our Vacaville pollinator garden this year. This occurred Oct. 9.
But the good news is that more monarchs are gathering on the overwintering sites along the California coast than this time last year. And this is occurring during a major drought year.
In an article, Monarch Butterflies Return to Pacific Grove. And the Drought May Be the Reason for Their Rebound, published yesterday (Oct. 21) in the San Francisco Chronicle, Tara Duggan wrote:
"For once there is some promising news for western monarch butterflies: Around 2,600 of the migratory insects were counted at Pacific Grove Thursday, after zero were observed at the famed Monterey County sanctuary last year. And overall, conservationists estimate the current population that has arrived in its annual wintertime migration to the California coast to be around 10,000 compared to 1,900 last year.
"One possible reason for the rebound: this year's drought, since warm and dry conditions in early spring can help with their migration."
Many others haves noticed the uptick, too. On Oct. 14, entomologist David James of Washington State University wrote on his Monarchs Butterflies of the Pacific Coast Facebook page: "Another exciting and encouraging update on monarch arrivals at the California overwintering sites. Combining all the reports I've received over the past few days there are an estimated 1500 butterflies at 5 overwintering sites from Santa Cruz to Pismo Beach. And still the butterflies are arriving... The highest number at one site is about 700 at a site in the Pismo beach area. This exceeds the highest number seen at one site in 2020 (550 at Natural Bridges). Pacific Grove is reported to have about 200 butterflies. This is especially notable since none were recorded at this site in 2020. Inbound migration will continue for a few more weeks yet but even at this early stage we are close to exceeding the entire population counted at overwintering sites in 2020. Good news, indeed!"
Volunteers counted only 1900 on the overwintering sites along the California coast in 2020, according to the Xerces Society for Invertebrate Conservation. Compare that to approximately 29,000 in 2019 and almost 200,000 in 2017.
"But on Wednesday (Oct. 20) volunteers counted 8,000 of the butterflies at two groves in Pismo Beach, compared to 300 last year," wrote Duggan.
Scientists, including Art Shapiro, UC Davis distinguished professor of evolution and ecology, say the main reasons for the decline of the monarchs are habitat loss and pesticides.
Plant milkweed, plant nectar sources and lose the pesticides.
(Editor's Note: Due to UC ANR server issues, images aren't visible. Click on the icon to see the image)
- Author: Kathy Keatley Garvey
Hey, wait, take me with you!
No, leave me alone! Let me go!
Have you ever seen insects struggling to free themselves from the reproductive chamber of a milkweed blossom?
Instead of producing loose pollen grains, milkweeds produce pollinia, a waxy, sticky packet of golden pollen grains originating from a single anther. When bees and other insects forage for nectar in the "nectar troughs," where the pollinia are, they emerge with wishbone-shaped pollinia on their feet or other body parts. That is, if they emerge at all. Sometimes they die there; the reproductive chamber becomes a floral death trap.
What may seem like nature's appalling act of cruelty is actually a unique case of floral pollination, the transfer of pollina from one blossom to another.
"Milkweed flowers bloom in umbels which are clusters of individual flowers on stems that emerge from a common point," explains Eric Eldredge in an article published by the U.S. Department of Agriculture's Natural Resources Conservation Service. "Flowers of different species of milkweed differ in size, color, and fragrance, but all produce their pollen in waxy sacs called pollinia. The pollinia are located in two anther pouches adjacent to vertical stigmatic slits of the flowers. Pairs of adjacent pollinia are connected to each other by translator arms from a clamp located in the middle, called the corpusculum (Bookman, 1981). The complete structure is called a pollinarium."
"Insects that visit a flower to drink nectar struggle to grasp the slippery surfaces and may accidentally slip their leg, tarsus, mouthpart, or other appendage into the opening at the bottom of the stigmatic slit. This slit is formed by guide rails, which are lined with bristles that prevent the insect moving its appendage any direction but up. The top of the slit leads into the opening of the corpusculum, which has hard, sharp inside edges that taper together at the top. The corpusculum clamps firmly to the insect by pinching onto the insect's appendage. In its struggles to escape, if the insect is large enough, it can withdraw the paired pollinia from the anther pouches and fly away."
We've seen dead honey bees trapped in the milkweed blossoms while other bees forage around their carcasses. And then we've seen the frantic struggles (below). Fortunately this bee in the first three photos escaped. Another bee did not.