INFLUENCE OF THE NUMBER OF ATTENDANT WORKERS ON THE NUMBER OF SPERMATOZOA ENTERING THE SPERMATHECA OF INSTRUMENTALLY INSEMINATED QUEENS KEPT OUTDOORS IN MATING NUCLEI
J. WOYKE AND Z. JASINSKI
A total of 160 queens were, instrumentally inseminated with 8 nun3 of semen. The queens were introduced to l- or 4-comb mating nuclei containing 8 different numbers of workers, ranging from 0 to 1000. The nuclei were placed outdoors and the temperature was measured three times a day. Two days after insemination, 5 out of 20 queens without any attendant workers had died, and all the others had some semen still in their oviducts. Almost all queens attended by 100 or more workers had oviducts clear of semen. The lowest numbers of spermatozoa (1'4 and 1'2 million) entered the spermatheca of queens kept in land 4-comb nuclei without any workers. Presence of 50 workers doubled the number of spermatozoa entering the spermatheca to 2'6 and 2'7 million. Further increase up to 200 workers only slightly increased the number of spermatozoa in the spermatheca, but an increase up to 350 attendants resulted in 3'7 and 3'6 million spermatozoa in the spermatheca, 3 times as many as in queens without workers, and 1'4 times as many as in queens attended by 50 workers. Further increase of the number of workers up to 1000 gave little or no increase in the number of spermatozoa in the spermatheca (means 3'95 and 3'68 million, but difference not significant). The gradual increase of the population of attendant workers raised the temperature in the bee cluster from 18'0 to 31·6°C. It is concluded that, to get normal numbers of spermatozoa in the spermatheca, at least 350 workers should attend instrumentally inseminated queens kept outdoors in mating nuclei.