Seasonal variations of colony activities linked to morphometric and glands characterizations of hybrid Carniolan honey bee (Apis mellifera carnica Pollmann) workers

Abstract

Objectives: The activity and productivity of the honey bee colony depend upon many factors operating simultaneously and reacts to some environmental conditions. We aimed to study the morphometric characteristics and glands development of nurse and forager of hybrid Carniolan honey bee (Apis mellifera carnica Pollmann) workers in relation to activities of the colony during the different seasons. Methods: The study was conducted during spring, summer, fall, then winter in 2020/2021. Ten colonies of hybrid Carniolan honey bees, every colony with about 14,000 bees, were utilizedz. The seasonal variations of foraging activity, hoarded pollen area, and sealed brood area were determined. Also, the body weight, some morphometric characteristics, and development of glands of nurses and foragers bees were measured. Results and conclusions: The highest numbers of foragers and pollen foragers/colony/min., stored pollen area, and worker sealed brood area were recorded in May. Measurements of nurses reared during spring were larger than nurses and foragers of other seasons for body weight, mandibular and hypopharyngeal glands (HPGs), length and width of the 2nd wax mirror. The highest proboscis and corbicula lengths were found in foragers reared during spring, without significant differences between worker castes. It can be concluded that the performance of the colony, morphometric characteristics, and development of glands were dependent on the time of the year. Beekeepers in Kafrelsheikh province and similar environmental condition areas should provide the colonies with pollen substitutes or supplements during April, June, and October to February to maintain the strength of the colonies.

Keywords

• Brood
• Foragers
• Hypopharyngeal glands
• Mandibular glands
• Nurses
• Wax glands