Composition and flight activity of Staphylinidae (Coleoptera) in citrus orchards

Staphylinid beetles are among the most important epigeic polyphagous arthropods living in various agro-ecosystems and represent an important component of functional biodiversity. Their flight activity in citrus orchards is still poorly investigated and, since most of them are insect predators, many species may play important roles in pest control. The aim of this study was to gain knowledge of the flying staphylinid fauna and its temporal distribution in citrus orchards. A survey was carried out, from December 2009 to August 2011, in a 70ha citrus farm located in the typical orange production area of Sicily. Two types of flight interception trap techniques were used: (i) 12 window traps maintained over one year and the trap content was serviced fortnightly, and (ii) 21 samplings carried using a net-car trap. The sampled Staphylinidae belong to 150 species, with 30 representing more than 90% of the whole sampled material. The most abundant, presented in decreasing order of collected number of specimens, were: Megarthrus bellevoyei, Anotylus nitidulus, Gabronthus maritimus, Paraphloeostiba gayndahensis, Scopaeus debilis, A. speculifrons, Cordalia obscura, Amarochara umbrosa, Proteinus atomarius, Carpelimus corticinus, Philonthus concinnus, Heterothops minutus, S. mitratus, Tachyporus nitidulus, Aloconota gregaria, Atheta palustris. Peak of flight activity for most species was typically in spring or spring-autumn, while species with strictly summer and winter peaks were a minority. Only some of the sampled species have been reported as potential biocontrol agents of citrus pests and further investigation is needed to assess the ecological services that they can provide in an integrated pest management framework. The results proved that several predatory staphylinid species do fly actively within a citrus orchard, suggesting the importance of increased knowledge on the dynamics of movement from neighboring ecological infrastructures to citrus cultivations.