Jan. 11, 2013
His talk, set from 12:10 to 1 p.m. in Room 1022 of the Life Sciences Addition, will double as his exit seminar. He received his doctorate in June 2012 from UC Davis, with major professor Phil Ward. He will be introduced by Ward.
Branstetter, who now works in the Department of Entomology, National Museum of Natural History, will discuss Stenamma, ants previoulsy known as "leaf-litter ants," but which are also arboreal and found in clay banks, among other places.
"For my Ph.D. research I have been investigating the taxonomy and phylogeny of the ant genus Stenamma, a group of cryptic leaf litter ants, which have a Holarctic-Neotropic distribution pattern," he says. "Using molecular phylogenetics I have shown that Stenamma is separated into two large clades, a Holarctic clade and a Middle American clade. With this result, I have been revising the Middle American clade of Stenamma and will be describing over 30 new Stenamma species. On-going work aims to understand the biogeography and natural history of Middle America species."
An abstract of his Jan. 16th seminar:
Stenamma comprises an intriguing genus of cryptic, cold-tolerant ants, which occur throughout the temperate zone and Central America. The group was considered to be a primarily Holarctic lineage, until collecting by the Leaf Litter Arthropods of Mesoamerica (LLAMA) project uncovered a trove of new species, which rival the Holarctic forms in terms of richness, as well as morphological and behavioral diversity. The LLAMA project also revealed that within the Neotropics, Stenamma can be abundant and dominant in high-elevation wet forests, a habitat inhospitable to most ants. These observations led to the formulation of several questions: What is the origin of the Middle American Stenamma species assemblage? Is it composed of multiple lineages that have dispersed south from North America, or could it represent the ancestral stock from which the temperate forms arose? Similarly, is the adaptation to cold tolerance a feature that evolved in the tropics along elevational gradients, or is it the product of temperate seasonality? Using evidence from phylogeny, biogeography and natural history, I attempt to answer these questions and to determine what other factors have been most important in the evolutionary history of this atypical and overlooked ant genus.
Of his fascination with ants, he says:
"Ants are the most successful group of social insects on the Earth. They occur in almost all terrestrial habitats and are often numerically dominant and ecologically important. Furthermore, ants are diverse. There are likely to be over 20,000 species worldwide and among these species there is a staggering amount of morphological and behavioral variation. It's not just the red ant and black ant. Some species are predatory and have large trap-jaw mandibles. Some are farmers, growing fungus gardens inside their nests. Some are parasites of other ant species, living in host nests and taking advantage of a tricked worker force. And some have huge migrating colonies that go on massive raids to collect food."
He's also "intrigued by this diversity and have devoted myself to discovering and describing species and behaviors. Most of my work focuses on using morphology and genetic data to determine what species are, but I also spend lots of time in the field making direct observations about behavior and ecology."
Born in Toledo, Ohio, Branstetter grew up in Kalamazoo, Mich. "It was not until I entered college at The Evergreen State College in Washington state that I became interested in science and eventually entomology," he says. His passion for entomology ignited when he took a class by his now colleague Jack Longino. During this class, "Insects and Plants of Washington," he became fascinated with insects and ants, Longino's specialty.
Later Branstetter took another course by Longino on tropical rainforests "and I had the opportunity to travel and work in Costa Rica for two-months. During the course I did a project on ant behavior at the La Selva Biological Station. It was during this time that I decided that I was interested in studying the systematics of ants."
The following summer Branstetter interned at the California Academy of Sciences, participating in its Summer Systematics Institute. "I worked on bee morphology and was exposed to insect taxonomy," he recalled. "During the internship I made the decision that I would go to graduate school to study insect systematics and I started writing my applications. The following year I was accepted into grad school at Davis with Phil Ward and began my career as an ant taxonomist."
The ants he studies are "special because they are an example of a group that originated in the temperate zone and later dispersed into the tropics. Within the tropics they have radiated in mid- to high-elevation wet forests, sometimes becoming the most dominant ant. This is in contrast to most other ants, which usually peak in diversity and abundance in the lowlands."
"It is my hope that studying Stenamma diversity and ecology will yield insights into the factors that have helped ants become so successful. Also, the genus has many undescribed species in Middle America. Describing these species and making identification keys will allow others, such as ecologists or conservation biologists, to identify them in their work. Of particular importance are the montane species, which may be in danger of extinction due to climate change."
Branstetter's seminar will be recorded for later viewing on UCTV. The seminars are coordinated by assistant professors Brian Johnson and Joanna Chiu. Professor James R. Carey coordinates the videotaping project.
(Editor's Note: Laura Sáenz in Nicaragua took these three photos while the ant specialists were doing field work for the Leaf Litter Arthropods of MesoAmerica (LLAMA) project. Of the first photo, taken in Parque Nacional Cerro Saslaya, Branstetter says: "The litter was hung in Winkler extraction sacks for three days to collect arthropods and then dumped out." The second photo shows Branstetter standing next to a Winkler hanging structure, constructed in the forest by their field guide who used only a machete. The third photo, taken at Reserva Nacional Kahka Creek, shows him in the process of doing a transect of mini Winkler samples. In his hands he has a machete, a Winkler sifter, and a sample bag. Underneath him is a 50 m measuring tape, used to mark sampling points. "I'm completely soaked in sweat, because this site was near sea level in lowland rainforest, meaning it was VERY hot and VERY humid. Not easy work, especially with the mosquitoes.")
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894