| Affiliation: | (1) Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel;(2) Department of Entomology, Institute of Plant Protection, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel;(3) Tzrifin, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel;(4) Institut für Organische Chemie , Universität Hamburg, Hamburg, Germany |
| Abstract: | Summary. Worker policing in honeybees predicts theevolution of a mechanism to discriminate between queenandworker-born eggs. Although it has been postulated thatthis discrimination is based on an egg recognitionpheromone, neither the chemistry nor the glandular sourcewere elucidated. To verify whether egg discrimination mightbe based on structural differences, we compared the ultrastructuresurface of queen-laid diploid and haploid eggs tothat of worker-laid eggs using SEM. Only small differencesbetween the different types of eggs were found. Thus, atleast based on the fine structure of the egg surface, queeneggs are indistinguishable from worker-laid eggs.To explore the chemosensory hypothesis for egg discrimination,we conducted a detailed comparative chemicalanalysis of the different egg types. The coating of all eggtypes was dominated by linear alkanes, but queen eggs,diploid and haploid, differed from those of workers on twoaccounts: 1. The diversity of compounds found on queenlaideggs was much greater than found on worker-laid eggs,mainly due to the number of hydrocarbons. 2. Acetates ofsome fatty alcohols, alkenes and especially monomethylalkaneswere characteristic to queen eggs. The origin of thetwo latter substances and the acetates is still unknown.Whether these compounds constitute the signal that enablespolice workers to discriminate between queen- and workerborneggs remains to be investigated. |
