searching efficiency is a key parameter of functional response which is in turn the major components in the selection of predators and parasitoids for biological control. searching efficiency of scymnus syriacus mulsant feeding on aphis craccivora koch was determined at five different experimental arenas (i.e. 195, 247, 304, 385 and 650 cm2) on broad bean (vicia fabae l.). to do this, functiona...