The Ants and Butterflies of Gates Canyon: Quite the Ecosystem

Gates Canyon, located just outside the city of Vacaville,  in Solano County, Calif., is quite the ecosystem.

• It's one of the habitats of the California state insect, the California dogface butterfly, Zerene eurydice, and its host plant, false indigo, Amorpha californica--or at least it was before massive wildfire swept through there on Aug. 19, 2020. 
  
  
• It's one of 10 research sites of butterfly guru Art Shapiro, UC Davis distinguished professor of evolution and ecology, who has monitored central California's butterfly populations since 1972 and maintains a research website at https://butterfly.ucdavis.edu/

And now, it's the home of a newly discovered ant species. 

Myrmecologists Brendon Boudinot, Marek Borowiec and Matthew Prebus, all alumni of the Phil Ward laboratory, UC Davis Department of Entomology and Nematology, just published their collaborative research,   "Phylogeny, Evolution, and Classification of the Ant Genus Lasius, the Tribe Lasiini and the Subfamily Formicinae (Hymenoptera: Formicidae)," in the journal Systemic Entomology.

The ant world on Twitter is crawling with congratulatory comments and how "awesome" the work is.  Wrote one:  "Congratulations! Lasius is a familiar genus in Japan, so I will let the Japanese entomologists know about it."

The story behind the story? It all began in the Ward lab. "The Three Ant Men" are now scattered from Idaho to Arizona to Germany.

• Borowiec, who received his doctorate at UC Davis in 2016, is an assistant professor at the University of Idaho.
• Prebus, who received his doctorate at UC Davis in 2018, is a postdoctoral scholar at Arizona State University. 
• Boudinot, who received his doctorate at UC Davis in 2020, is in Jena, Germany on a two-year Alexander von Humboldt Research Fellowship to research evolutionary and comparative anatomy.

Boudinot says "this work was eight years in the making—trials and tribulations were the order of the decade." The study began with a challenge. "Phil told us of a population of highly unusual species of Lasius from Gates Canyon Canyon near Vacaville, L. atopus, and wondered if we would be able to find a colony. The three of us drove to Gates Canyon on March 22, 2014 and spent several hours flipping rocks and digging in this steep-sided and poison-oak-filled ravine until we found one! We proceeded to hack our way through the poison oak roots to collect as many specimens as possible.

Said Boudinot: "With these strange, elongate Lasius in hand and under the microscope, we realized that the population likely represents a new and closely related species, but we held off on describing the species, instead choosing to focus on the hypothesis that L. atopus belonged to the Chthonolasius subgenus, as postulated in 1958 by Art Cole. Under Marek's leadership, we proceeded to sequence this population of L. atopus, along with eleven other carefully chosen species from the genus for phylogenetic analysis, and we presented our results at the 2014 Entomological Society of America meeting in Portland Oregon. Specifically, we found that L. atopus does not belong in Chthonolasius, and on top of that the nominotypical subgenus, Lasius (Lasius) was polyphyletic, that is, an unnatural grouping that excludes some daughter lineages while also including distantly related species."

In addition to presenting their results at the ESA meeting, they submitted their study as a manuscript to Systematic Entomology, "which is when we experienced an acute episode of tribulation as our work was rejected for being too preliminary, despite our diverse taxon sampling and incisive molecular dataset," Boudinot recalled. "Undaunted, we expanded our taxon sampling, this time sequencing several species collected by other colleagues, including Marek's father. To our tremendous surprise, we discovered that one of these newly sequenced taxa, the recently described Grecian species Lasius myrmidon was, in fact, not a Lasius at all! Rather, this species turns out to be an ancient and isolated relictual lineage, sister to the mightily diverse Prenolepis genus group, which itself is the closest relative of the Lasius genus group. After many starts and stops, the project lay dormant as Marek and Matt completed their dissertations, and I focused on getting mine into shape.'

Looking back, Prebus and Borowiec said that they were both interested in Lasius atopus "due to its strange morphology and lack of phylogenetic data despite the amount of attention paid to the genus, and planned a collecting trip to the type locality in Mendocino County in 2013."

The collecting trip to Mendocino proved unsuccessful. "But because of Phil's extensive collections. we knew of a population of a closely related species in Gates Canyon near the city of Vacaville," Prebus said. This time the trio collected specimens from several colonies at Gates Canyon, which is located off Pleasants Valley Road.

"For all of us, this was a collaborative side project, so after the study was presented, submitted, and rejected, it took the back-burner while people finished their dissertations, got jobs, got married, had kids, and so on," Prebus recalled. "Speaking personally, the pandemic put quite a few of my postdoc projects on hold after the Arizona State University campus closed, but the small upside amongst the inundation of downsides was that I was able to focus on getting some long-haul projects into shape for publication, including the Lasius study. This involved a huge amount of reanalysis of data that we had already collected, but thankfully didn't require generating any new data."

See more on the ant research on the UC Davis Department of Entomology and Nematology website.

(Note that the 7.8 mile Gates Canyon Road, lined with residential homes (private property) and "no trespassing" signs, is a paved county road that leads to the top of Mount Summit, the highest point in Vacaville. It is narrow and hilly. Hikers, runners, walkers and bicylists consider it a challenge.)