Landscape parameters explain the distribution and abundance of Episyrphus balteatus (Diptera: Syrphidae)
Sarthou, J.P.(Ecole Nationale Superieure Agronomique de Toulouse, Auzeville-Tolosane (France))E-mail:sarthou@ensat.fr | Ouin, A. | Arrignon, F. | Barreau, G. | Bouyjou, B.
We studied the importance of forest structure (shape, edge length and orientation) and the crop mosaic (within 100 and 2,000 m from the forests) to the dynamics of Episyrphus balteatus. Adults were collected by Malaise traps located within and on the south- and north-facing edges of 54 forests. In winter, E. balteatus was only found on south-facing edges because of the greater insolation and temperature. In summer, it was more abundant on north-facing edges because of the abundant presence of flowers. In spring, more adults were found on long and south-facing edges than on northern ones. The presence of shrubs within 2,000 m also positively affected abundance. In autumn, abundance was positively associated with length of the north-facing edge and forest shape. Emergence traps revealed that in southern France, E. balteatus may overwinter in the larval or puparial stage in forest edges. The abundance is influenced by landscape structure.
显示更多 [+] 显示较少 [-]