Stimulating feeding and development of hypopharyngeal and thoracic glands of honeybees (Apis mellifera L.)

R. Shumkova1, I. Zhelyazkova2*

1Experimental Station of Stockbreeding and Agriculture, 4700 Smolyan, Bulgaria
2Department of Animal Science, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

Abstract. The effect of some stimulating products on the development of the hypopharyngeal (HPhG) and the thoracic glands (ThG) of worker bees was studied. The investigation was conducted in the spring period of 2012 at the Experimental apiary of the Experimental Station of Stockbreeding and Agriculture (ESSA) in Smolyan, Bulgaria. Products ‘Vita Feed Gold (VFG)’, ‘Apidas’, ‘Oligofosi’ and ‘Anolyte-7’ were used for stimulating feeding of bee colonies. Five groups, each of five bee colonies were formed. Samples from bees for investigation of HPhG and ThG were taken after finishing the feeding. The state of glands was determined in non-flying 5-10-day worker bees (30 from each colony). The 4-point scale of Hess (in rates, Maurizio, 1954) is used for establishing the degree of development of hypopharyngeal glands. The diameter of 10 glandular blebs of HPhG of each bee is additionally measured. Height and diameter of 10 glandular tubes are measured and their volume is calculated for determining the degree of development of the thoracic glands of each bee. Binocular loupe MBS-1 with ocular micrometer is used for measurement. It is established that with the highest degree of development are HPhG of worker bees (3.90±0.06 rates and 0.102±0.0017 mm diameter of glandular blebs), receiving with their food ‘VFG’ – respectively, 1.06 and 1.27 times more than bees from the control group. From the studied stimulating products, the preparation ‘Apidas’ (includes plant extracts) is also with well expressed positive effect on the development of HPhG of bees. The obtained values of the studied parameter in bees receiving ‘Anolyte-7’ (electrochemically activated water solution) and those of the control group are commensurable. Positive influence of preparations ‘Apidas’ and ‘VFG’ on the volume of the measured glandular tubes from the thoracic glands of worker bees is determined. The reported values for volume of glandular tubes in bees receiving with their food the indicated stimulating preparations (0.005 and 0.004 mm3) are 2.0 – 2.5 higher than the studied parameter in bees from the control group (0.002 mm3) and those fed with ‘Anolyte-7’ (0.002 mm3) and ‘Oligofosi’ (0.001 mm3).