No abstract

Complex socio-economic, political and demographic factors have driven the increased conversion of Europe’s semi-natural grasslands to intensive pastures. This trend is particularly strong in some of the most biodiverse regions of the continent, such as Central and Eastern Europe. Intensive grazing is known to decrease species diversity and alter the composition of plant and insect communities. Comparatively little is known, however, about how intensive grazing influences plant functional traits related to pollination and the structure of plant-pollinator interactions. In traditional hay meadows and intensive pastures in Central Europe, we contrasted the taxonomic and functional group diversity and composition, the structure of plant-pollinator interactions and the roles of individual species in networks. We found mostly lower taxonomic and functional diversity of plants and insects in intensive pastures, as well as strong compositional differences among the two grassland management types. Intensive pastures were dominated by a single plant with a specialized flower structure that is only accessible to a few pollinator groups. As a result, intensive pastures have lower diversity and specificity of interactions, higher amount of resource overlap, more uniform interaction strength and lower network modularity. These findings stand in contrast to studies in which plants with more generalized flower traits dominated pastures. Our results thus highlight the importance of the functional traits of dominant species in mediating the consequences of intensive pasture management on plant-pollinator networks. These findings could further contribute to strategies aimed at mitigating the impact of intensive grazing on plant and pollinator communities.

Tropical Old World species of the genus Discomyza are redescribed, including male terminalia, photographs of heads and wings. One new species Discomyza fagomoga sp. nov. is described from D. R. Congo, Ethiopia, Kenya and Uganda. Two new synonyms are proposed: Discomyza obscuricornis Canzoneri and Rampini, 1996 = D. dolichocerus Cresson, 1944 and D. intermedia Canzoneri and Meneghini, 1969 = D. eritrea Cresson, 1939. A key to all species is provided. Relationships among species of Discomyza are suggested.

Diagnoses and illustrations of three Leptopsilopa species known in the Old World: L. africana Cresson, L. mutabilis Cresson and L. pollinosa (Kertesz) are provided. Three new synonyms are proposed: L. aurata (Canzoneri and Meneghini) and L. tibialis (Canzoneri and Meneghini) = L. africana; Psilopa confeteae Canzoneri and Munari = L. pollinosa. Three other species are removed from Leptopsilopa and combined with Athyroglossa, as A. leonensis (Canzoneri and Rampini), new combination, A. mianii (Canzoneri) new combination and A. rossii (Canzoneri and Raffone), new combination.