Honeybees Dufour's gland - idiosyncrasy of a new queen signal

Dufour's gland (DG) secretion of queens in Apis mellifera is normally caste specific. In queenright (QR) workers it is composed of odd n alkanes, while in queens it also possesses long chain esters. However, glandular expression is plastic since queenless (QL) workers produce a queen-like secretion. Moreover, QR gland incubated in vitro produced these esters, indicating that glandular activity is regulated. We tested the hypothesis that the secretion is an egg marking pheromone. Chemical analysis of the egg coating revealed minute amounts of the queen esters, but neither queen secretion nor the synthetic esters were able to protect worker-laid eggs from policing, refuting the hypothesis. Analysis of abdominal tips further revealed that Dufour's egg secretion is also smeared on the abodominal cuticle, suggesting that its presence on egg surface may be due to passive contamination. Next, we tested the hypothesis that the secretion serves as a queen signal. Indeed queens, but not worker glandular secretion were attractive to workers

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In-nest environment modulates nestmate recognition in the ant Camponotus fellah Abstract Multiple behavioral and chemical studies indicate that ant nestmate recognition cues are low-volatile substances, in particular hydrocarbons (HCs) located on the cuticular surface. We tested the hypothesis that in the ant Camponotus fellah, nest environment, in particular nest volatile odors, can modulate nestmate-recognitionmediated aggression. Workers were individually confined within their own nest in small cages having either a single mesh (SM = limited physical contact permitted) or a double mesh (DM = exposed to nest volatiles only) screen. Individual workers completely isolated outside their nest (CI) served as control. When reintroduced into a group of 50 nestmates, the CI workers were attacked as alien ants after only 2 weeks of separation, whereas the SM workers were treated as nestmates even after 2 months of separation. Aggression towards DM ants depended on the period of isolation. Only DM workers isolated for over 2 months were aggressed by their nestmates, which did not significantly differ from the CI nestmates. Cuticular HC analyses revealed that the profile of the nonisolated ants (NI) was clearly distinct from that of CI, SM and DM ants. Profile differences matched the aggressive response in the case of CI ants but were uncorrelated in the case of SM or DM ants. This suggests that keeping the ants within the nest environment affected nestmate recognition in additional ways than merely altering their HC profile. Nest environment thus appears to affect label-template mismatch by modulating aggressive be-T. Katzav-Gozansky ( ) )