Monarchs on the move...so many mysteries.

Where do Western monarchs go after leaving their overwintering sites along coastal California in February? 

An observation: They didn't stop in the spring or summer to deposit eggs on any of our four species of milkweed in our Vacaville pollinator garden. 

Spring? Zero. Zilch. Nada.

Summer? Zero. Zilch. Nada.

Fall? Yes.

Why not spring and summer? Did the monarchs passing through Vacaville opt for "a better habitat" in the cooler Pacific Northwest and beyond (British Columbia)?

"I wish I knew," commented UC Davis distinguished professor emeritus Art Shapiro, who has monitored the butterfly populations of Central California since 1972 and maintains a research website, Art's Butterfly World.

Beginning in September, as many five monarchs a day began fluttering into our garden. Some laid eggs.

To date, we've spotted some 20 eggs and caterpillars.

"This is generally consistent with the pattern we've seen in previous years," said UC Davis Department of Entomology and Nematology professor Louie Yang, who researches monarchs. "Even in Davis, we've been seeing more caterpillars in the late summer/fall. I think this is probably because some are stopping to lay eggs on the return migration, and the fall population is much larger than the spring migration population. Looking very carefully, we did also see eggs in the spring each year, but very few of them developed into large caterpillars." See the Louie Yang et al, research paper, "Different Factors Limit Early- and Late-Season Windows of Opportunity for Monarch Development," published in July 2022 in the journal, Evolution and Ecology.

The availability of food resources, such as tropical milkweed (Asclepias curassavica) that can overwinter in warmer climates, doesn't deter them from migrating, said UC Davis emeritus professor Hugh Dingle of the Department of Entomology and Nematology. Dingle, an internationally known expert on animal migration who has studied monarchs for more than two decades, said: "Migration and the diapause that accompanies it in the fall are determined by shortening photoperiod and temperature (warm temps can override short days hence the issue with climate change)."

Fall breeding and egg-laying? "Since we don't know exactly where they are coming from, it is hard to know why this is so common," Dingle said. "The long warm autumn probably helped by promoting higher survivorship, but who knows?" 

Said UC Davis professor Elizabeth Crone of the Department of Evolution and Ecology: "Monarchs may behave similarly in spring, but the spring population is probably much smaller than the fall one, so they are less likely to happen across your garden.  Our estimate is that the population increases 2-3x each generation (so it's about 100-200x larger in Fall than Spring), then resets each year due to mortality during Fall migration and overwintering. There is some research from Sonia Altizer's lab in Georgia showing that monarch butterflies that encounter milkweeds during fall migration will leave reproductive diapause and breed.  It is unknown whether these monarchs are effectively lost from the migratory population, or whether they or their offspring (the caterpillars in your yard) will continue on to the overwintering sites."

"The egg-laying females you are seeing now are likely migrants that have eschewed reproductive dormancy for reproduction," says entomologist David James, an associate professor at Washington State University who researches migratory monarchs. "This has probably always happened to some extent but is likely more significant now because of warmer falls."

"The lack of activity in summer in Vacaville was probably a function of most of the population having dispersed further east and north, maybe more than usual? They surely did pass through Vacaville in spring on their way north but clearly didn't stop to use your milkweeds. It does seem that some years they are more prone to frequent stopping/oviposition on their way north and east, yet in others they just keep flying. There's evidence that the latter was the case this year... with as many migrants making it to BC as to Washington... Normally they stop in Washington and only a handful make it to BC."

"The many mysteries of monarchs," James added.

James is the author of a newly published book,  The Lives of Butterflies: A Natural History of Our Planet's Butterfly Life (Princeton University) with colleague David Lohman of the City College of New York. The book, released in the UK on Oct. 3, 2023, will be available in the United States starting Jan. 9, 2024.

Irish scientist Éanna Ní Lamhna recently interviewed the WSU entomologist in a podcast on RTÉ, or Raidió Teilifís Éireann. The book, she said, "showcases extraordinary diversity of world's butterflies, while exploring their life histories, behavior, conservation and other aspects of these most fascinating and beguiling insects." (See Bug Squad blog)

Listen to the butterfly podcast here: https://www.rte.ie/radio/radio1/clips/22294525/ 

Meanwhile, are you seeing fall breeding and egg-laying in your garden? We have for more than a decade, with some monarchs eclosing in November and December. 

Meet UC Davis doctoral alumnus Murray Isman, who has just received monumental recognition.

Isman is listed as No. 2 among the world's top two percent of entomologists in a database announced by Stanford University with data from Elsevier's “science-wide author databases of standardized citation indicators.” 

Isman is internationally recognized for his discoveries and development of botanical insecticides and antifeedants, and for research in insect-plant chemical interactions and insect chemical ecology.

Isman, who received his doctorate from UC Davis in 1981, is the dean emeritus of the University of British Columbia's Faculty of Land and Food Systems and emeritus professor of entomology and toxicology at UBC. He's a Fellow of the Entomological Society of America (ESA).

A native of Vancouver, B.C., Isman received his bachelor's degree (1975) and his master's degree (1977) from the University of British Columbia before heading to UC Davis for his doctorate.  A postdoctoral position in insect toxicology at UC Irvine followed.  In 1983 he accepted a position as assistant professor in the  UBC Department of Plant Science, attaining the rank of professor in 1994. He  served as dean of the Faculty of Land and Food Systems at UBC from 2005–2014.

At UC Davis, Isman was the second graduate student of the late Sean Duffey. Faculty member Bruce Hammock, now a UC Davis distinguished professor, was a member of Isman's supervisory committee. "I think the last time I saw Bruce was in 2010 (also the last time I was on the UC Davis campus) when I delivered the Thomas and Nina Leigh Distinguished Alumni Seminar to the Department of Entomology," he wrote this week in an email.

ESA heralded his work in his 2014 Fellow biosketch: "Early in his career he became known for his thorough studies on neem insecticides and azadirachtin, helping to bring some clarity to research of variable quality, dubious claims, and redundancy. More recently he worked with a team to provide research and development support for EcoSMART Technologies Inc., propelling the company to become the world leader in pesticides based on plant essential oils. While Isman became an authority on the development of pesticides based on natural products, he maintained basic research on insects, with fascinating observations on insect feeding and oviposition behavior, insect memory, and the metabolism of plant toxins by insects." 

The biosketch singled out his teaching, research and public service, and his many accomplishments.  Among his many honors, received the Entomological Society of Canada's Gold Medal in 2011, the C. Gordon Hewitt Award (1991) for outstanding achievement by an entomologist under the age of 40, and the PheroTech Lifetime Achievement Award in 2014. In 2010 he delivered the Thomas and Nina Leigh Distinguished Alumni Lecture at UC Davis.

Murray presided over the International Society of Chemical Ecology (2002), the Phytochemical Society of North America (1993, he remains the only entomologist to have done so), and the Entomological Society of British Columbia twice (1988 and 1999). He also organized and chaired two conferences in Vancouver: the 14th Annual Meeting of the International Society of Chemical Ecology (1997) and the Fourth World Neem Conference (1999).

Isman related in the ESA biosketch that he enjoys "hockey, motorsports, contemporary and native art, and fine wine."

He still does. 

"I officially retired in mid-2018, but served as Interim Director of UBC's Wine Research Centre from mid-2017 until mid-2020," Isman shared. "I spend most of my 'professional' time now serving on editorial boards of three international journals, reviewing grant proposals and continuing to do some modest consulting to pesticide companies in the USA and Australia."

"My main recreational activity is playing ice hockey (twice a week) with different senior (60+) teams.  As a goalie, I hope to keep playing as long as my knees permit!"

He and his wife Susie have a daughter and a son. The Ismans will be in San Francisco for Thanksgiving to visit their daughter (a Columbia, UBC and UC-Berkeley alumna) and son-in-law (a Harvard and Oxford alumnus).

"I really should make a return visit to Davis on a future trip, something I suggested to (UC Davis distinguished professor and friend) Walter Leal."

Leal, who chaired the UC Davis Department of Entomology in 2006-2008 before accepting a position in 2008 as professor of biochemistry in the Department of Molecular and Cellular Biology, is listed in the Stanford/Elsevier database as No. 22 among the world's top entomologists.

Other UC Davis entomologists on the list, in the order of ranking, are:

• Jay Rosenheim, No. 68
• Harry Kaya, 206
• Fumio Matsumura (1934-2012), 208
• James R. Carey, 232
• Robbin Thorp (1933-2019) 321
• Christian Nansen, 452
• Lester Ehler (1946-2016) 593
• Robert E. Page Jr., 548
• Frank Zalom, 557

Elsevier. Elsevier, a global information analytics company that helps institutions and professionals progress science, advance healthcare and improve performance, published its "science-wide author databases of standardized citation indicators" on Oct. 4, 2023. The ranking of scientists is at https://elsevier.digitalcommonsdata.com/datasets/btchxktzyw. It is a publicly available database "of top-cited scientists that provides standardized information on citations, h-index, co-authorship adjusted hm-index, citations to papers in different authorship positions and a composite indicator (c-score). Separate data are shown for career-long and, separately, for single recent year impact. Metrics with and without self-citations and ratio of citations to citing papers are given. Scientists are classified into 22 scientific fields and 174 sub-fields according to the standard Science-Metrix classification. Field- and subfield-specific percentiles are also provided for all scientists with at least 5 papers. Career-long data are updated to end-of-2022 and single recent year data pertain to citations received during calendar year 2022. The selection is based on the top 100,000 scientists by c-score (with and without self-citations) or a percentile rank of 2% or above in the sub-field. This version (6) is based on the October 1, 2023 snapshot from Scopus, updated to end of citation year 2022. This work uses Scopus data provided by Elsevier through ICSR Lab (https://www.elsevier.com/icsr/icsrlab). Calculations were performed using all Scopus author profiles as of October 1, 2023. If an author is not on the list it is simply because the composite indicator value was not high enough to appear on the list. It does not mean that the author does not do good work."

Scientists from China filtered the list to spotlight only entomologists. The list is at https://wxredian.com/art?id=9f6eea221698e282/. (See UC Davis news story)

Love insects and arachnids?

Members of the Entomology Graduate Student Association (EGSA)  of the UC Davis Department of Entomology and Nematology design insect and arachnid-themed T-shirts that are all the fashion.

The critters climb, crawl, jump, roll, flutter, buzz, fly or otherwise position themselves on EGSA T-shirts.

If you've ever seen the EGSA booth at Briggs Hall during the campuswide annual UC Davis Picnic Day, you know how popular the T-shirts are.

They are hot-ticket items during the holiday season, too. They can be viewed and ordered online at https://mkt.com/UCDavisEntGrad/. 

EGSA president Mia Lippey, a doctoral student in the laboratories of UC Davis distinguished professor Jay Rosenheim and assistant professor Emily Meineke, says that currently, the designs offered are:

1. The Beetles (in black or red)
2. Entomo Gothic (a play on the American Gothic, in grey)
3. Whip Scorpion (in lavender and black)
4. Bee-Haw (in black)
5. They See Me Rollin' (dung beetles rolling a poop, in heather blue)
6. Et in Terra (dark green)
7. Entomophagy (in blue and green)

All T-shirts come in sizes from XS to XXL. 

"The Beetles" T-shirt is EGSA's all-time best seller. Instead of the English rock band John Lennon, Paul McCartney, George Harrison and Ringo Star crossing Abbey Road in single file (that's the iconic image on the cover of their album, Abbey Road), think of The Beetles (four insects) crossing Abbey Road in single file. Beneath the images of the beetles are their family names: Phengogidae, Curculionidae, Cerambycidae and Scarabaeidae. Think glowworm, snout, long-horned, and scarab beetles.

One of the newer designs is "Bee Haw," of a honey bee disguised as a cowgirl, complete with hat and rope.  The entomophagy ("eating insects") T-shirts are also "in," as are those that whip and roll--whip scorpions and dung beetles. 

They are also great conversation pieces! What's that design on your shirt? Where did you get it?

Sometimes overlooked as pollinators are the syrphid flies, also known as "hover flies" or "flower flies."

Unfortunately, they are often mistaken for honey bees. Hey, if it's a critter on a flower, it's a bee, right?

Not necessarily!

Syrphid flies are easily distinguished from honey bees. Among the differences: (1) honey bees don't hover,  (2) syrphids have only one pair of wings, while honey bees have two  (3) syrphids have short, stubby antennae, while honey bees have long, bent antennae called genticulate antennae and (4) syrphids belong to the order Diptera, while honey bees are in the order Hymenoptera.

We spotted this syprhid fly soaking up some early-morning sun  It stayed still for a dorsal photo and then sensing danger, slipped under a leaf.

Scientists estimate that there are more than 6200 species of syrphid flies in the world, and more than 3000 in California alone.

The UC Statewide Integrated Pest Management Program (UC IPM) has this to say about syprhids in its Natural Enemies Gallery post: "Adults are robust to slender flies 1/8 to 1 inch (4–25 mm) long, varying by species. The broad head is about the width of the abdomen or wider and has large eyes with distinct antennae. The body of many adults is black with bands or stripes of orange, yellow, or white, resembling stinging bees or wasps. Some species are mostly brown, metallic blue or green, yellow, or combinations of these or other colors. For example, adults of ant-predaceous Microdon species are blackish to brown or bright to dark greenish."

Many syrphids prey on aphids and mealybugs, so they're good guys and gals to have in your garden. 

Says UC IPM: "Most species are predaceous, most commonly on aphids or mealybugs. Some syrphids prey on ants, caterpillars, froghoppers, psyllids, scales, other insects, or mites."

The good guys and gals of the garden...