Coexisting aphid (Hemiptera: Aphididae) and ant (Hymenoptera: Formicidae) communities : interdependence in various habitats

The paper presents the comparison of species diversity and evenness indices calculated for coexisting communities of aphids and ants. In six study areas, localised in Upper Silesia (Poland), representing acidophilous oak-forest (Molinio caeruleae - Quercetum roboris), moist meadow (Molinietum caeruleae) and xerothermic grassland (Sileno-Phleetum) the community structure of aphids and ants (species number and abundance) was determined. The number of ant nests and aphid colonies was determined by searching the squares of 25 m2 during vegetation seasons in 2006 and 2007. This provided the base to calculate the Shannon.s diversity index and evenness index of both groups. Spearman's rank correlation analysis showed significant correlation only in the case of the number of species of both groups in a particular study area. It showed no significant correlation of values of diversity and evenness indices; however, considerable differences of values between both groups in various habitat types were recorded. The results are discussed with reference to the habitat history and maintenance, also reflecting the mutualistic relationship between ants and aphids.