Variation in Hygienic Behavior and Its Associations with Colony-Performance and Wing Morphometric Traits Among Honey...

Honey bee hygienic behavior is an important colony-level defense trait with potential relevance to selective breeding. The aim of this study was to evaluate variation in hygienic behavior among honey bee colonies from five apiaries in Kazakhstan and to examine its associations with colony-performance traits and wing morphometric characteristics. Hygienic behavior was assessed in 50 colonies using the pin-killed brood assay, with brood removal recorded 24 h after treatment. Significant differences in hygienic behavior were observed among the five studied apiaries (p < 0.001), with the highest mean brood-removal efficiencies recorded in the Nurik and KazNARU apiaries and the lowest in the Baizhigitov apiary. Principal component and hierarchical clustering analyses revealed multivariate differentiation among colonies based on behavioral, performance, and morphometric characteristics. Although the cubital index was strongly correlated with hygienic behavior in the pooled analysis, the within-apiary association was not statistically significant after accounting for apiary identity (β = 9.42, 95% CI: -2.82 to 21.65, p = 0.128), indicating that the overall relationship was primarily attributable to differences among apiaries. However, because apiary identity is associated with ecological conditions as well as potentially differing management practices and honey bee population backgrounds, these patterns should not be interpreted as independent causal effects of ecological conditions. The findings provide baseline information on variation in hygienic behavior and associated phenotypic traits in honey bee colonies from Kazakhstan and support further studies incorporating broader environmental, management, and genetic characterization before their potential application in selective breeding programs.