The true bugs, or heteropterans, are known for their widespread production of anti-predator chemicals and alarm pheromones in scent glands, a derived trait that constitutes one of the defining characters of the suborder Heteroptera and a potential novel trait that contributed to their diversification. We investigated whether symbiotic bacteria could be involved in the formation of these chemicals using Thasus neocalifornicus, a coreid bug that produces semiochemicals frequently found in other bugs. Using DNA phylogenetic methodology and experiments using antibiotics coupled with molecular techniques, we identified Wolbachia as the microorganism infecting the scent glands of this bug. Decreasing the level of Wobachia infection using antibiotics was correlated with a diminution of heteropteran production of defensive compounds and alarm pheromones, suggesting that this symbiotic bacterium might be implicated in the formation of chemicals.

The authors wish to emphasize that they are not claiming that the defensive chemicals and alarm pheromones of all Heteropterans are produced by symbiotic bacteria. They worked with a single species, Thasus neocalifornicus, and it remains to be determined whether the chemical defenses of other Heteropterans also are produced partly or wholly by symbionts. The online version of the original article can be found at http://dx