Systematics, phylogenetics, and evolution of insects
Quarantine and exotic pests
Conservation of honeybees, wild bees, and plant pollination

1989.01 ~ 2003.02 Research Scientist, National Academy of Agricultural Sciences, Korea
1996.09 ~ 1997.09 Visiting Scientist, Canadian National Insect Collection, Ottawa, Canada
1999.09 ~ 2000.07 Visiting Scientist, Institute of Entolology, Czech Academy of Sciences, Ceske Budejovice, Czech
2003.03 ~ present Professor, Department of Entomology, Seoul National University, Korea
2013.07 ~ 2015.07 Associate Dean of Research Affairs, College of Agriculture and Life Sciences, Seoul National University
2009.09 ~ 2010.08 Director, Plant Hospital, Seoul National University
2016.04 ~ 2020.07 President, Vice President, Korean Society of Apiculture
2016.04 ~ present Vice President, Korean Society of Applied Entomology