I was fortunate to receive a BRAVO! grant to go to South Africa to conduct research on the physiology of tsetse flies (Diptera, Glossinidae). I worked in the S.P.A.C.E (Spatial Physiological And Conservation Ecology) group at Stellenbosch University in South Africa. My research advisor at The University of Arizona, Dr. Allen Gibbs (now at UNLV), is currently involved in collaboration with the SPACE Group investigating desiccation and cuticular water loss in arthropods. The S.P.A.C.E group, working closely with the Center of Excellence for Invasion Biology (CIB), is directed by Professor Stephen Chown.

The SPACE group is large by any standard and research conducted in it spans the gamut of ecology, physiology, and conservation work. My research placed me with a capable group of individuals studying cold physiology of insects as a means to a greater understanding of ecology, and the influence of climate on biogeography. The research group is involved in numerous projects, mainly throughout southern Africa, and the sub-Antarctic islands.

My research concerns a physiological temperature tolerance mechanism, or specifically a response to a pre-treatment, known as rapid cold hardening (RCH), in tsetse flies (Glossina pallidipes). Rapid cold hardening was first reported in 1987 in Drosophila. Drosophila die after an hour at -5.5°C, but pre-exposure of the flies to 4°C for 30 minutes allows the flies to survive an hour at temperatures below –7°C (Chen et al. 1987). The term rapid cold hardening is not specific to the phenomenon it describes; it was subsequently discovered that RCH can be induced both by high and low temperatures, and has even been induced with desiccation and anoxia. As such, RCH probably serves as a general response to several, not necessarily temperature, stressors. The ecological application of RCH is that it can increase the operative ‘window’ at which insects survive and are active at both high and low temperatures. Investigating RCH can help predict the impact global climate change will have on tsetse distribution, and subsequently, the distribution of both human and animal diseases of which tsetse are the vector.

I received my flies from a laboratory colony maintained by the Entomology Unit, FAO/IAEA Agriculture and Biotechnology Laboratory, Seibersdorf, International Atomic Energy Agency, Vienna, Austria. This G. pallidipes colony has been maintained for approximately 25 years, and was originally started from flies collected in Tororo, Uganda. Using laboratory colonies avoids the possibility of infection with sleeping sickness (Trypanosoma brucei) from wild-caught flies, and several screening processes are in place to ensure that this does not happen.

I investigated whether or not rapid cold hardening could occur in G. pallidipes. To do this, I experimentally determined the lower lethal temperature (LLT) of G. pallidipes. With the LLT, survival rates at different cold temperatures can be determined, and differences in survival with a pre-treatment can be quantified. If different pre-treatments elicit statistically significant decreases in mortality, than the animals are demonstrating rapid cold hardening. My data indicated that certain treatments could elicit RCH in this species of fly, although considerable variation in response to pre-treatments was observed.

Working in the SPACE group and in the Zoology Department at SU also gave me the opportunity to participate in many different projects underway at the time. I was welcomed along on fieldwork on a number of projects. I backpacked in areas off-limits to the public (due to endangered plants) for a project monitoring microclimates along an altitudinal gradient. I banded birds for a project examining the role of sexual selection in male ornamentation of sugarbirds. This is in addition to trips examining densities of invasive tree species, as well as a lab project testing the repeatability of a method of measuring cuticular water-loss in arthropods (developed by the Gibbs lab).

I am profoundly grateful to the BRAVO! program for giving me the opportunity to engage in meaningful research, in a setting I otherwise would most likely not have arrived at during my undergraduate studies. Funds are not always plentiful (an understatement) in scientific research worldwide. It is quite extraordinary that the BRAVO! Program allows UA undergraduates to go abroad and do real research in areas of their interest. Experiencing the differences in research methods and philosophies of a foreign lab is infinitely valuable for anyone looking at pursuing a career in scientific research. Being able to participate in and reap the benefits of international scientific collaboration as an undergraduate is almost nothing short of incredible. I would highly recommend any research-oriented students explore the possibilities that the BRAVO! Program offers.

I would like to thank Professor Stephen Chown and many members of the research group, as well as the Department of Zoology at the University of Stellenbosch. None of this would have been possible without the guidance and mentoring of Dr. Allen Gibbs and others at the University of Arizona. I would also like to thank Carol Bender and the BRAVO! Committee for giving me the support to embark on this project. Financial support for this program was provided by a grant to the University of Arizona from the Howard Hughes Medical Institute (#52003749).

Ben Pri'Tal, BRAVO! student from Dr. Allen Gibbs’s lab, Ecology & Evolutionary Biology and Entomology