Environmental aspects determining richness of predaceous diving beetle species (Family Dytiscidae)

Abstract

Introduction: Aquatic beetles from the Dytiscidae family are known as predatory
diving beetles. This group of insects, with more than 4000 species, is the largest and
the most diverse family of aquatic insects. The aim of this study was to identify the
environmental aspects affecting the population of this type of aquatic beetles.
Materials & Methods: Sampling was done seasonally with the help of a net and a
special sampling net for one year at six stations in the Shahrekord region, and ecological
factors such as water temperature (WT), water pH and water electrical conductivity
(EC) were measured. The data were analyzed with the help of linear regression and also
through Canonical Correspondence Analysis (CCA).
Results: CCA bi-plots and linear regression showed that water temperature with a
correlation coefficient of 1.336 has the strongest effect on the distribution of the aquatic
beetles (P<0.01). In addition, this study showed that the measured variables (pH, EC,
WT) are excellent predictor variables in the direction of the richness of the predaceous
diving beetles.
Conclusion: The results of the present study showed that the ecological factors
affecting the richness of predaceous diving beetle population are shown as follows:
water temperature > water EC > water pH