A Five-Year Study of the Flying Beetles (Coleoptera) from a Grassland and an Adjacent Woods in Southern Québec (Canada)

During the entire snow-free season (April or May to October) in 2006-2010, we collected with four flight interception traps a total of 34 629 individuals of 848 Coleoptera species belonging to 60 families in southern Québec (Canada). We catched mainly phytophagous and zoophagous beetles. The majority of species (621 or 73,2%) were represented by less than 10 adults over the five years; however, we collected at least 100 adults for 48 species, including four major species: Meligethes nigrescens Stephens (15,9% of the total catches), Longitarsus luridus (Scopoli) (10,6%), Eusphalerum pothos (Mannerheim) (9,1%) and Acidota subcarinata Erichson (5,9%). Between 39 and 47% of species from a trap were collected in one month only over the five years; whereas E. pothos and M. nigrescens flew mainly in May and June, and adults of A. subcarinata and L. luridus were collected mainly in September and October. Over 2006-2010, we catched a total of 9214 individuals of 439 species in the grassland, 7503 individuals of 519 species at the woods edge, 5943 individuals of 356 species in the woods, and 11969 individuals of 468 species near a ditch parallel to the woods. We consider that the curve of the cumulative number of species for each trap over 33 months in five years may indicate a good estimation of the flying beetle species richness in a site. Seven species were dominant in at least one trap over 2006-2010: A. subcarinata, Bradycellus nigrinus (Dejean), Cercyon assecla Smetana, E. pothos, Isochnus rufipes (LeConte), L. luridus and M. nigrescens. In a window trap, some dominant and subdominant species showed considerable fluctuation in percentage from year to year, particularly E. pothos, L. luridus and M. nigrecens. Also, we believe that, in the future, it will be important to explore variations of beetle biodiversity on long time.