Publications and Presentations

Terrestrial isopods are poorly studied in North-America. Even though they significantly influence ecosystem functioning such as litter decomposition and nutrient cycling, extensive distribution data is lacking. We present the first results of an ecological atlas of the terrestrial isopods of Maryland and Washington D.C. based on literature data, museum collections, citizen science data and a statewide inventory covering more then 350 locations. We found 24 species, of which only five are native. Seven species are new to the region, two of which are native. National parks are important for the conservation of rare native species bound to old and wet forests and coastal habitats. Large national parks are one of the few areas not yet invaded by non-native species, but it seems to be a matter of time before this happens. Our study is the first statewide inventory, significantly contributing to the natural history of terrestrial isopods in North America.

Chaetophiloscia sicula Verhoef, 1908 (Philosciidae) is a small terrestrial isopod of Mediterranean origin. It has been recorded from Greece, Spain, Italy, France, Crimea, Canary Islands, Roumania, and from greenhouses in England. In its native region,  Chaetophiloscia sicula is found in open, shrubby habitats called maquis.  In North America, Chaetophiloscia sicula was first reported in 2000 from an urban forest in Baltimore, Maryland, and from the nearby Homewood campus of the Johns Hopkins University3  . The species was thought to be a recent introduction localized to  the Greater Baltimore Metropolitan area.  Recent observations changed our view on the status of this species on the continent.

The terrestrial isopod fauna of North America is poorly studied mostly because the low number of native species. Most non-native species were introduced from Europe, successfully colonized virtually all habitats, and became extremely abundant. Woodlice (Isopoda: Oniscidea) are decomposers and crucial for nutrient cycling, litter decomposition and water retention, thus detailed knowledge on the distribution of both native and non-native species is important to understand their effect on ecosystem functioning. As part of an ongoing collaboration between Dr. Pallieter De Smedt, University of Ghent, Belgium and Dr. Katalin Szlavecz, Johns Hopkins University, Baltimore, MD, the entire state of Maryland was surveyed to create distribution maps for all terrestrial isopod species. The team discovered many new state records of both native and non-native species increasing the species list by 50%. However, they failed to find one species, the elusive Scyphacella arenicola that had not been seen for 120 years in the state.