The Rare ButterflyTomares Nesimachus(Lycaenidae) as a Bioindicator for Pollination Services and Ecosystem Functioning in Northern Israel

Abstract

Evidence suggests that insects whose existence depends on fruit production may serve as good bioindicators, especially for pollination services. In this study we examined this hypothesis, focusing on one of Israel's rarest butterflies, Tomares nesimachus (Rhopalocera; Lycaenidae). The butterfly is affiliated with open grasslands in the north of Israel, where its sole host plant, Astragalus macrocarpus, occurs. In a two-year field study, we mapped the distribution of the butterfly in Israel and tried to evaluate the causes of its rarity and decline. We found that its abundance in habitat patches was correlated with several factors, including (a) fruit production of the host plants in each patch, (b) the number of other patches in the vicinity, (c) the characteristics of the outside the patches within a distance of up to 2 km, (d) the richness of large bee species (the plant pollinators), and (e) the grazing management of the butterfly's habitat. The characteristics of the matrix further affected t...