|Zarbin, P.h.g. - Universidade Federal Do Parana|
Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/14/2014
Publication Date: 12/15/2013
Citation: Aldrich, J.R., Zhang, A., Zarbin, P. 2013. Exocrine secretion of wheel bugs (Heteroptera: Reduviidae: Arilus spp): clarification and chemistry. Journal of Chemical Ecology. 68(11):522-526.
Interpretive Summary: Except for the blood-sucking kinds of assassin bugs that transmit disease, assassin bugs (family Reduviidae), are highly beneficial predators of many pest insects. Despite their importance as predators and disease vectors, little is know about the chemicals reduviids use to communicate. Wheel bugs (genus Arilus) are among the largest and most widespread of all assassin bugs. We discovered that these predators possess a gland that has been mistakenly assumed (in the North American species) to serve a defensive role in adult males and females. Actually, this gland is present in only females and likely produces an aroma (a pheromone) that attracts males. This information expands the knowledge of chemical communication in this group of predacious insects, which will be useful to researchers interested in using behavior-modifying chemicals for husbandry of assassin bugs.
Technical Abstract: Assassin bugs (Heteroptera: Reduviidae) in the genus Arilus are among the largest of the New World reduviids, and can inflect extremely painful bites. The most common North American species, A. cristatus (the “wheel bug”), possesses eversible osmeterial glands that reportedly produce an obnoxious odor when the adults are disturbed. The South American species, A. carinatus (known as “stegosaur”) possesses a similar osmeterial gland; however, this gland reportedly occurs only in adult females and gives off a pleasant, orange-like aroma. In fact, only adult females of A. cristatus possess an osmeterial gland, as in A. carinatus. However, when molested, Arilus spp. simultaneously release secretion from another set of exocrine glands common to most assassin bugs (the so-called Brindley’s glands), which produce extremely rancid smelling secretions. Here we correct this semiochemical confusion regarding the exocrine glands of Arilus spp., and present chemical evidence suggesting that the female-specific osmeterial glands of Arilus, at least in A. carinatus, produce a sex pheromone.