1Institute of Applied Biochemistry, University of Tsukuba, 1-1-1 Ten-nou dai, Tsukuba, Ibaraki, 305-8572 Japan.
2PRESTO, Japan Science and Technology Corporation (JST), c/o National Institute of Sericultural and Entomological Sciences (NISES), 1-2 Oowashi, Tsukuba, Ibaraki, 305-8634 Japan.
Differences in mandibular glands components between honey bee castes have attracted an special interest because of their distinctive functional differences and of their structural similarity: Queen substances (9-oxo-2-decenoic acid, 9-hydroxy-2-decenoic acid, etc.) from queen Apis mellifera function as sex attractants towards drones, suppresser of ovary development against workers and more. On the other hand, functions of 10-hydroxy- 2-decenoic acid and 10-hydroxydecanoic acid from worker mandibular glands are not so clear as queen substances. In the course of our study on semiochemicals in honey bees in Asia, (R)-3-hydroxyoctanoic acid was identified as a forager specific predominant component in worker mandibular glands of Apis cerana japonica. GC and GC/MS analyses of honey bees (A. mellifera, A. cerana japonica, A. c. cerana, A. c. indica, A. c. himalaya, A. andreniformis, A. laboriosa, A. dorsata) and bumble bees (Bombus terrestris, B. hypocrita hypocrita, B. ignitus, B. diversus ) revealed that 2-alkanones 2-heptanone and 2-nonanone) and 3-hydroxy fatty acids (C8-C10) were present in the worker mandibular glands as common components among four subspecies of A. cerana and bumble bees. 2-Heptanone is known as one of the alarm pheromone in Apis spp. A solitary parasitic wasp was found to secrete a mixture of 2- and 3-alkanones as allomonal signals. 3-Hydroxy fatty acids were identified as antifungal agents from leaf cutting ant, Myrmica atta. A key to the sociality lies in the signal proccessings in CNS to give meanings to the ubiquitous chemicals such as alkanones and hydroxylated fatty acids, does it ?