Habitat preferences of Maculinea arion and its Myrmica host ants: implications for habitat management in Italian Alps

摘要: Projections of climate-change scenarios indicate that many Maculinea arion populations will disappear from Europe over the next 50 years. Extinctions be particularly concentrated around southern limits species’ range, such as Italian peninsula, except mountain populations, mainly in Alps. M. is a social parasite Myrmica ants and its survival depends on presence abundance two resources, i.e. (1) specific larval foodplant (2) suitable host ant. We collected data Thymus plants distribution, abundance, turf height nests, distance between nests closest thyme plant (Thymus pulegioides), vegetation structure at 14 patches fragmented population occurring Western Alps (Val Ferret: Aosta). found with highest had significantly higher abundance. Among 407 belonging to nine species, we larvae one lonae sulcinodis nests. The distribution showed best spatial overlap plants. was also more abundant pastures showing high density, therefore offered adoption probabilities develop butterfly larvae. On habitat patches, mean varied 10.5 22.3 cm matched requirements T. pulegioides. Thus, suggest extensive grazing needed maintain most important resources for arion. Moreover, where included numerous species characteristic these pastures, well diversity (Shannon index). As consequence, represents an umbrella good indicator conservation status grasslands.