Effects of Varroa destructor on sugar levels and their respective carbohydrate hydrolase activities in honey bee drone prepupae
Krystyna Zóltowska, Zbigniew Lipinski and Malgorzata Dmitryjuk
Varroa mite feeding caused a significant decrease in glycogen and trehalose levels during the prepupal stage of drone honey bees (Apis mellifera carnica). At the same time, the two groups were not statistically different with regards to free glucose concentration. Concentrations of glycogen, trehalose and total sugars in varroa-infested drone prepupae were (32.4 mg/g, 15.4 mg/g, and 66.8 mg/g), respectively, while levels in uninfested prepupae were (49.3 mg/g, 21.3 mg/g and 114.5 mg/g, respectively). The activities of glucoamylase (0.84 u/mg) and trehalase (1.37 u/mg) in varroa-infested prepupae were also significantly higher in the infested prepupae than in non-infested controls (0.54 u/mg and 0.78 u/mg, respectively). Interestingly, the activity of invertase was significantly lower in infested prepupae.