Insect Diversity in Eastern Mediterranean Maquis Exhibits Extensive Variation Between Sites and Years, Complicating Monitoring Efforts

Insects are understudied in the Eastern Mediterranean, a region with heterogeneous biotas facing rapid regional warming and land-use changes. It is essential to establish a baseline for insect monitoring, including the extent of spatial, inter-annual, and seasonal variations in insect diversity and composition—all prominent in the Mediterranean. To assess these, we conducted an intensive three-year (2022–2024) sampling of ants and plant-dwelling beetles at three sites along Mt. Meron’s maquis-covered western slopes (Galilee, Israel, at 550, 850, and 1050 m above sea level), with similar tree, shrub, mammal, and bird communities. Results show high inter-annual variability of beetle species (~15% of species were collected in all three years; ~ 65% only in one of the study years), and a lesser but still significant spatial variation between sites (~50% in only one of the sites; 20% in all sites). In both respects, 30 collection events have not reached 90% of the total multi-annual detected species list. In ants, similar but less pronounced results were found. These findings underscore the need for a multi-year, multi-site intensive sampling effort to compile a complete species list as a baseline for trend monitoring of the Mediterranean maquis and warrant a discussion on its methodology.