The distribution of the genus Lestes in a saline lake series in central British Columbia, Canada (Zygoptera: Lestidae)

L. congener Hag., L. disjunctus Sel, and L. dryas Kirby were found to be common inhabitants of a saline lake series on the Chilcotin Plateau of central British Columbia. L. unguiculatus Hag., the only other sp. of the genus in British Columbia, did not occur in the region, although it is characteristic of similar habitats at lower elevations 130 km to the south. — In the lakes studied, ionic concentrations and compositions differed considerably. Conductivities ranged from 72 to 15524 mieromhos/cm at 25°C; the main cations were sodium and magnesium and the main anions were carbonate and bicarbonate. /., dryas colonized only the fresher water bodies, those with conductivities up to 1254 micromhos/cm and pH levels below 9.0. while L. disjundus occurred in lakes with conductivities up to4892 micromhos/cm and pH measurementsto9.0.1., congener inhabited the complete range of salinities examined and occurred in very large numbers even at the upper limit of conductivity and at a pH of 9.3. Emergence and mating of the 3 spp. were temporally separate; dryas emerged 10 or 11 days before disjundus, which preceded congener by 9 days. The main disjundus emergence occurred approximately 20 days before the peak of the congener emergence. – The possible influences of salinity on both the distribution of the species within the lake series and the timing of their emergence were examined.