Boundaries of Alfalfa Field and Their Function as Refuge for Butterfly (Lepidoptera: Rhopalocera) Communities

Abstract

Farmland edge plants can support high butterfly richness. Our objective was determine if, even in farms under intensive cultivation, the diversity of plants (mostly native) in crop edges is enough to sustain a high species richness of butterfly. We characterized the vegetation on the edges of Medicago sativa farms in central Mexico and identified the species of diurnals butterflies (Rhopalocera) associated. Butterflies and plants were counted along transects at the edges of a cul-tivated field during 24 months. We found 2710 individuals of plants, belonging to 48 different species from 24 families; 1749 individuals of diurnal butterflies, belonging to 57 species from six families. Most than half of the plant species found were native flora of central Mexico and with ethnobotanical use. A similarity analysis test showed significant differences in floristic composi-tion between transects. The Canonical Correspondence Analysis between butterfly species and plant families showed three groups. Six butterfly species were migratory and four mexican en-demic species, most of them associated with a group formed by Amaranthaceae, Euphorbiaceae, Annonaceae Lamiaceae Apiaceae and Fabaceae families. The high diversity of plants in our agro-ecosystem plays an important role to sustain a high diversity of butterflies and could be useful as biological corridors.