Historical changes in the biodiversity of northern Muscidae and Fanniidae (Diptera: Muscoidea) of the Churchill region (Manitoba)
Anaïs Renaud, Department of Entomology, University of Manitoba, Winnipeg, MB, R3T 2N2
Jade Savage, Department of Biological Sciences, Bishop’s University, Sherbrooke, QC, J1M OC8
Anaïs Renaud is an entomology student pursuing a master’s degree at the University of Manitoba. She is co-supervised by Dr. Jade Savage (Bishop’s University) and Dr. Rob Roughley (University of Manitoba). Anaïs spent the summer of 2007 sampling Diptera in Churchill, Manitoba.
Churchill, Manitoba: a fascinating site for researchers
Known as the polar bear capital of Manitoba, Churchill is located on the west coast of Hudson Bay at the level of the 58 parallel. In this area, three biomes meet: marine, tundra, and boreal forest. It is a rich and dynamic environment where researchers have a unique opportunity to conduct field work, as well as enjoy an extraordinary experience. Easy to access by train or plane from Winnipeg, the area of Churchill can be explored with a vehicle on its paved and gravel roads.
The “Churchill” that older entomologists have known is different from the one of today. Between 1942 and 1980, an important United States Air Force military base was located about 8 km east from the actual town of Churchill. The seaport has also changed; today there is more activity with increased grain exports to Russia. Tourists are more numerous and frequent. With the increase of tourism in the area, human activity has changed as has the landscape.
The research project: objectives and hypothesis
The research project aims to provide a new baseline for the muscid and fanniid flies of Churchill. The last inventories of these flies in Churchill were carried more than 40 years ago and they yielded 113 species of Muscidae and 6 species of Fanniidae (Webb 1956, Huckett 1965). Under current trends of global warming, the temperature of most arctic localities has risen twice as fast as in most other areas of the world over the last decades (Hassol 2004). Since temperature is one of the most important factors affecting insect distribution (Battisti et al. 2005), we expect the distribution of the muscids and fanniids of Churchill to have changed over the last decades.
The Muscidae is a dominant group in northern ecosystems, while Fanniidae are less diverse and abundant. The 2007 inventory will provide an estimation of the species composition and abundance of both Muscidae and Fanniidae of this region. After compiling data from the literature and visiting various insect museums of North America to record specimens collected in Churchill before 2007, past and recent data will be compared. Changes in species composition for the area will be recorded and we expect trends such as the absence of northern specialists and northern range expansions from southern taxa. DNA sequences of all recorded species will be submitted to the database associated with the Polar Barcode of life initiative (PolarBol). DNA barcoding may also enable us to assign some ambiguous females to the proper species, as many muscid females are notoriously difficult to identify based on morphology alone.
For 12 weeks, from mid-June to the end of August, approximately 20,000 specimens of muscid and fanniid flies were collected using Malaise traps, pan traps, and sweep nets at a total of 34 sites. Eight permanent and six temporary sites were chosen to set up Malaise and pan traps while 20 other sites were chosen for sweeping. Wapusk National Park (Broad River and Lapérousse Bay) and the Prince of Wales Fort National Historic Site were part of the survey. Flies were collected in various habitats like the tundra, coniferous forest, Hudson Bay shores, Churchill River bank, regenerating forest, poplar plantation, and fen. So far, 5,000 specimens have been mounted and labeled and the remaining material is currently being processed. Preliminary identifications have already provided two new records of muscids for Churchill. Taxonomic identification will be completed in the upcoming year in Dr. Savage’s laboratory in Sherbrooke, Quebec.
Battisti, A. M. Stastny, S. Netherer, C. Robinet, A. Schopf, A. Roques, and S. Larsson. 2005. Expansion of geographic range in the pine processionary moth caused by increased winter temperatures. Ecological Applications 15(6): 2084–2096.
Hassol, S.J. 2004. Impacts of a Warming Arctic: Arctic Climate Impact Assessment. Cambridge University Press, Cambridge, U.K.
Huckett, H.C. 1965. The Muscidae of Northern Canada, Alaska, and Greenland (Diptera). Memoirs of the Entomological Society of Canada 42: 1–369.
Webb, J.E. 1956. Observations on some filth flies in the vicinity of Fort Churchill, Manitoba, Canada, 1953–54. Journal of Economic Entomology 49: 595–600.