Altitudinal variation of sexual size dimorphism in ground beetle Carabus odoratus Shill.

Abstract

Samples of Carabus odoratus barguzinicus Shil. сollected in different altitudes of Barguzin Mountain Range at the northeast part of Baikal Lake (N 54° 20'; E 109° 30', Russia). In total eight populations were analyzed, two in each belt: Coast, Low-, Middle-and High Mountains (455-460, 500-700, 701-1300, 1301-1700 m above sea level). Morphometric measurements included six traits (elytra length and width, pronotum length and width, head length, and the distance between eyes) of 1300 specimens. Sexual size dimorphism (SSD) in Carabus odoratus was female-biased. Its value was significant and more pronounced in Low-and High mountains and varied from 0.01 to 0.1 in different traits and at different altitudes. The largest values of SSD was at Low-and High mountains. The latter considered the most favorable biotopes to the species studied. RMA II method resulted in positive Intercepts in most traits treated. That demonstrated the higher sensitivity of females to environmental conditions and that Carabus odoratus follows the opposite Rensch′s rule.