Odonatological Abstracts

(16501) BENDELL, B.E. & D.K. McNICOL, 1995. Lake acidity, fish predation, and the distribution and abundance of some littorial insects. Hydrobiologia 302:133-145. — (Can. Wildlife Serv,, Ontario Region, 49 Camelot Dr., Nepean, ON, KIA 0H3, CA). Densities of Corixidae (Hemiptera), larval Odon., and large larval Trichoptera were estimated in the littoral zone of small lakes in an acid-stressed area near Sudbury, Ontario, Canada. Fish were present in some lakes and absent in others, and fishless lakes occurred across a wide range of pH. Anisopt. larvae tended to be more numerous in benthic samples from fishless lakes than from lakes with fish, and their exuviae were significantly more abundant around fishless lakes. In most lakes, the assemblage was dominated by Leucorrhinia glacialis, Libellula Julia, and Cordulia shurtleffi. In lakes containing white sucker (Catostomus commersoni) Gomphus spp. were most numerous. In the most acid fishless lakes, L. Julia was uncommon, and L. glacialis was extremely abundant. In fishless lakes, numbers of Anisopt. larvae and exuviae were negatively correlated with pH, though species richness was positively correlated with pH. Exuviae of Zygopt. were more abundant around fishless lakes, irrespective of pH. (16502) DOUPE, R.G. & P. HORWITZ, 1995. The value of macroinvertebrate assemblages for determining priorities in wetland rehabilitation: a case study from Lake Toolibin, Western Australia. Jl R. Soc. W. Aust. 78: 33-38. — (Second Author: Dept Envir. Mngmt, Cowan Univ., Joondalup Dr., Joondalup. WA 6027, AU). Xanthagrion erythroneurum, Austrolestes annulosus, A. io, and Hemianax papuensis are listed from the northern Arthur R. wetlands (lakes Dulbinning and Walbyring), WA, Australia. The salinity concentrations of the sites are stated.