Submitted to: Naturwissenschaften
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 10, 2003
Publication Date: N/A
Interpretive Summary: Natural sources are being investigated in search of new leads for insect repellents. In the course of this research, it was learned that some monkeys in the wild apparently collect, crush and smear certain kinds of millipedes onto their fur so as to cover themselves with a secretion from the millipede that repels mosquitoes. Experiments were performed verifying that naive monkeys born and raised in captivity perform this behavior with millipedes or paper towels treated with synthetic chemicals mimicking the natural secretion. Separate tests were conducted showing that the synthetic chemicals actually do effectively repel mosquitoes. This information is of interest to scientists because it shows that natural extracts are potential sources for insect repellents and that, in at least some kinds of monkeys, recognition of potentially useful chemicals is innate rather than learned.
Many mammals and birds smear fruits, leaves, arthropods or other odorous materials onto their integuments. Some investigators suggest that these anointing behaviours serve to appropriate chemicals that deter ectoparasites. Recent observations of free-ranging wedge-capped capuchin monkeys (Cebus olivaceus) in Venezuela reveal that they rub the millipede, Orthoporus dorsovittatus, onto their pelage, and it has been hypothesized that they use the defensive secretions of this myriapod's numerous segmental glands to repel mosquitoes. We demonstrate here that the two known secretory components of O. dorsovittatus, 2-methyl 1-1,4-benzoquinone (toluquinone) and 2-methoxy-3methyl-1, 4-benzoquinone, deter contact and feeding by mosquitoes. These compounds, which are the predominant glandular products of the orders Julida, Spirobolida, and Spirostrepida occur in an approximately 1:1 ratio in the glandular exudate of O. dorsovittatus. We also report that these benzoquinones elicit anointing in capuchin monkeys (Cebus spp). Our study is unique in identifying naturally occurring compounds that both deter ectoparasitic arthropods and elicit anointing in mammals.