This article is from the archives of the UB Reporter.

Biologist hunts for bat flies and fleas

Published: December 6, 2007

Reporter Staff Writer

As a biologist, Katharina Dittmar de la Cruz says it’s important not to lose sight of the natural world while working long hours in the lab. Perhaps that’s why she’s set out on a planet-wide treasure hunt in which she regularly rappels into unexplored caves in remote jungles from South America to Southern Asia.


Katherina Dittmar de la Cruz frequently rappels into caves in remote jungles to scoop bats off rock walls. The UB biologist then removes flies and fleas from the bats before releasing them.

Dittmar, assistant professor in the Department of Biological Sciences, College of Arts and Sciences, joined the UB faculty this fall to continue an ambitious research project on the physical and genetic characteristics of bat flies and fleas she began while a postdoctoral researcher at Brigham Young University.

“I’m basically collecting bat flies and fleas all over the world,” she says, noting that the goal is to assemble a complete phylogeny—“essentially a ‘tree of life’”—containing a specimen of every known species of bat fly and flea on the planet. “Using the literature that’s already been compiled as a guide, we know there are about 2,400 species of fleas and roughly 800 species of bat flies,” she explains. “It’s an extremely comprehensive study.”

Bat flies and fleas interest Dittmar because they exemplify a unique type of evolutionary adaptation in which two creatures with distinct genetic histories develop similar physical traits due to similar environments. The process—known as convergence—is the reason bat flies, which infest bats in order to survive and have reduced or absent wings and eyes, may resemble fleas on the outside, despite ancestors similar to common house flies, she says.

Since bloodsucking parasites are vectors for disease—fleas, for example, transmit plague and typhus—she says researching them also has applications related to disease control and prevention.

Only after assembling as complete a collection of both groups as possible, however, will Dittmar be able to start piecing together a precise map of both species’ physical and genetic evolution.

“In order to answer the questions I’m asking, I’m basically using phylogenetics, which means I’m looking at genes from both these groups to extract historical information and then trace the evolution of particular characteristics,” she says. So far, she has collected 80 species of bat flies and 250 species of fleas—about 10 percent of all known species for each parasite.

“I’ve been all over the world doing field research,” she notes, checking off the places she has visited in search of parasites. “I’ve done field research in Argentina, Chile, Brazil, Peru, Bolivia, Dominican Republic, Puerto Rico, Malaysia. I’ve also been to Russia, Slovenia and Croatia. Pretty much the entire U.S. Also Canada and Mexico.”

A trained cave explorer and member of the National Speleological Society, Dittmar says she spends a lot of time in remote foreign caverns scooping bats off rock walls. “Either the bats hang low enough that we can sneak in and use these extendable poles with nets on top to pick them off the wall or we have to enter through a skylight or vent and rappel next to the roost—basically free hanging on the ropes—and pick the bats off,” she says. “The work conditions are very difficult.”

All but a few of the bats are released after the parasites are removed, Dittmar adds, pointing out that many of the species she captures are on the “red list” of the world’s most endangered animals. Environmental protection is a topic close to her heart, personally as well as professionally, she says. Her husband, Ronald de la Cruz, is a journalist working with the Library of the United Nations Framework Convention on Climate Change, which documents efforts to get every nation in the world to sign the Kyoto Protocol.

The recipient of a doctor in veterinary medicine from the University of Leipzig, Germany, in 1997, Dittmar earned a Ph.D. in molecular biology and entomology in 2001 through a joint program between the University of Leipzig and the Universidad Nacional Mayor de San Marcos in Lima, Peru, where she spent two years collecting parasites from South American rodents such as guinea pigs, which inhabit the high Andes, and capybara, the largest rodent in the world.

At UB, Dittmar says she plans to focus for the next several years on bat fly research funded by a $480,000 collaborative grant with the Field Museum in Chicago from the National Science Foundation. She plans to travel to Puerto Rico and Vietnam next year as part of the project. A typical field trip runs two or three weeks and involves five to eight people, she says, although certain countries are “politically tricky,” which limits the number of team members. Collaborators on these expeditions include students, as well as researchers from the Chicago Field Museum, where she is a research associate in zoology.

“Right now, I’m looking for undergraduate students to work in my lab,” she says, pointing to seven or eight applications lying on her desk. She says field research is a big draw for students—before going into the field she plans to take several to Pennsylvania or West Virginia to train them in cave exploration—and notes that working in her lab offers significant academic opportunities, including potentially publishing a research paper as an undergraduate.

“Two of my undergraduate students at BYU had really high-tier journal publications and one of them went on to Yale with a stipend,” she says. “The thing about my research, which is a little different from other faculty’s, is that it enables me to find small projects students can do on their own, even if they’re undergraduates.”

A native of East Germany—until the fall of the Berlin Wall when she was 14—and now a resident of the Village of Wilson on Lake Ontario, Dittmar says she’s adjusting well to her new job and home in Western New York.

“Having lived in the West my whole time in the U.S., it’s just closer here (in the East) to a European lifestyle,” she says. “The department here also struck me as being not only very diverse, but a mix of interesting people beneficial to my research and who my research can hopefully contribute to.”