VARIATION IN BODY SIZE ALONG GEOGRAPHICAL GRADIENTS IN GROUND BEETLES (THE CASE STUDY IN CARABUS GRANULATUS L.)

We tried to clarify Bergmann Rule for ectotherms taking as the model ground beetle Carabus granulatus. Carabid beetles are known as a fair and representative group, sensitive to environmental factors, suitable for ecological researches. We sampled beetles by pitfall traps in 8 large regions of Russia and abroad, the territory of investigations lied between 42.8 and 56.8 degrees from South to North and between 17.6 and 86.1 from West to East. In total 6172 specimens we measured by 6 linear traits. Linear and polynomial trends showed that elytra length, elytra width and pronotum width decreased in latitude gradient when using linear regression or showed hump-shaped variation in elytra width – when using polynomial regression. No variation in traits value was revealed in longitude gradient when using linear regression but polynomial regression curves were distinctly U-shaped for head length and distance between eyes in latitude gradient and hump-shaped – in longitude one. Variation in traits diversity (CV) was not significant in any traits. Our studies do not confirm the presence of a direct correlation between the variability of the sizes of individual traits and the variability of their coefficient of variation in the latitudinal gradient, which has been shown for some animals.