PHYSIOLOGICAL STUDIES ON HONEY BEES (APIS MELLIFERA L.) UNDER VARROA PARASITISM ( VARROA JACOBSONIOUD.)

Abstract

The gresent study was carried out by using Craniolian hybrid to study; 1- Effect.of the parasite Varroa jacobsorii on some morphological systems and glands of honey bees. 2- The histopathological effects of the parasite,on some systems and glands of honey bees. • 3- The physiological effects of the parasite on some haemolymph components of the workers. The obtained results are summarized as follows;

1- The mornhological studies. 1- Honey'beworkers: Under different degrees ofVarroa infested workers by 1-3, 4- .. 6 & up to 7 mites/ cell and deformed bees. The results indicated that; 1- clearly • decreased in the mean body weight in infested and deformed workers. 2- obviously decreased in length and width of the alimentary canal of infested and deformed bees. 3- markedly decreased in number of the hypopharyngeal gland 's lobvles and their measurements. 4- The mandibles and their mandibular glands were decreased in state of Varroa infestatio.n. 5- Negative effects in the measurements of the four wax glands and venom acid gland in infested worker with Varroa mites. 6- Markedly decreased in length of the ventral nerve cord of infested and deformed newly workers was parallel with decrease measurements of the nerve ganglia and interganglionic connectives length. 7- Length and width of fore and hind wings were clearly decreased in infested worker, while sharply decreased in length and width of the hind wing was detected in deformed bees. 8- The mean number of the longitudinal and vertical indirect wing muscles of healthy worker were 177.31 & 156, while they were 167.16, 144.5 & 155.13, 147.64 in infested and deformed worker,respectively. 2- Honey bee drones:. The obtained results revealed that 1- Reared drones in Varroa infested colonies showed markedly decreased in the mean body weight, and measurements of the reproductive system (testis, seminle vesicle & mucus glands). 2- Sharply decreased in length of the ventral nerve cord and size of their ganglia as well as lower length of the interganglionic connective nerve. 3- The mean number . of the longitudinal and vertical indirect wing muscles in non-infested newly emerged drones were 341.28 & 308.5, respectively while in case of Varroa infestation they were 268.5 & 246.75, respectively. 3- Honey bee queens: 1- Naturally or artificially rearing queens in Varroa infested colonies caused decrease in acceptance percent of grafted queen larvae (in the artificially rearing), number of capped queen cells; number & weight of the reproductive system (ovary and spermatheca)& measuremenfs of the virgin queen produced. 2- Newly naturally mated queens w•hich reared in Varroa infested colonies under 10% of infestation level indicated markedly decreased in the measurements of the reproductive system (length, width, volume, weight of the ovary and weight and volume of the spermatheca). 3- clearly decreased in some of thebiological activities (egg laying daily and capped brood worker area inc2 .