These flies were identified using:
Lonsdale, O., Cheung, D.K.B., and Marshall, S.A. 2011. Key to the World genera and North American species of Clusiidae (Diptera: Schizophora). Canadian Journal of Arthropod Identification, 14. doi: 10:3752/cjai.2011.14. Available from http://www.biology.ualberta.ca/bsc/ejournal/lcm_14/lcm_14.html