Evaluating Carniolan honey bee (Apis mellifera carnica) lines under contrasting ecological zones

Abstract

This study evaluates four breeding lines of the Carniolan honey bee, Apis mellifera carnica, across distinct ecological zones of Serbia and Montenegro. The objective was to assess phenotypic, morphometric, and isoenzyme polymorphism of local populations adapted to contrasting climatic and altitudinal conditions. Two Serbian lines (lowland Vršac and mountainous Vranje) and two Montenegrin lines (mountainous Bijelo Polje and coastal Sutomore) were examined. The material consisted of worker bees and queens from 40 honey bee colonies. Analyses included colony strength, brood development, honey and beebread storage, hygienic behavior, winter food consumption, queen reproductive performance, morphometric traits, and isoenzyme polymorphism based on six enzyme systems (MDH-1, ME, EST-3, ALP, PGM, and HK). Nei’s (1972) genetic distance, Ward's cluster analysis, and Neighbor-Joining algorithm were applied. The lines exhibited high morphological homogeneity with low genetic differentiation. Mountain populations showed lower winter food consumption and adaptive traits for high-altitude environments, whereas lowland lines displayed more intensive colony development. Two stable clusters corresponding to mountainous and lowland populations formed irrespective of national origin, confirming the decisive role of environmental factors in shaping A. m. carnica population structure and emphasizing the importance of preserving the local gene pool.