DEVELOPMENT OF LARVAE OF CHRYSOPS NIGRIPES ZETTERSTEDT AND CHRYSOPS PROBABLY ZINZALUS PHILIP (DIPTERA, TABANIDAE) IN A SUB-ARCTIC LABRADOR PEATLAND

A total of 476 tabanid larvae, including 108 Chrysops nigripes and 145 Chrysops probably zinzalus, were obtained from regular collections ma de from early June through late August 1990-1991 in Iron Arm Fen, a mi nerotrophic peatland located in subarctic Labrador near Schefferville, Quebec. Changes in head capsule and total body length-frequency distr ibutions among successive sampling periods and years suggest very slow growth rates for Chrysops species at subarctic latitudes; life cycles may require 7-8 years to complete.