TRUNK SIZE INFLUENCES SPECIES RICHNESS AND FUNCTIONAL COMPOSITION OF BIOGEOGRAPHICALLY DIFFERENT TREE-VISITING ANT COMMUNITIES IN PEAR ORCHARDS

Abstract

We investigated the diversity of ant assemblages visiting pear trees in Italy by comparing two orchards from a northern region with continental climate (Emilia-Romagna) and a southern region with Mediterranean climate (Sicily). Overall we identified 20 ant species belonging to 10 genera and 3 subfamilies. The ant communities of the two sites look significantly different in biogeographic terms, but their functional composition is similar. Moreover, we discovered that both ground and arboreal nesting species richness is positively correlated with the trunk circumference. In particular, arboreal-nesting species are limited to the deadwood richer medium and large trees. Some of the detected ant species may be useful to pest control strategies, and artificial nests may be considered to attract arboreal-nesting species in deadwood-poor trees. Key Words: arboreal ants, myrmecology, Sicily, Emilia Romagna.