10 - Perception and olfaction of cuticular compounds

Summary

When humans communicate with each other, we rely on an arsenal of acoustic sounds and signals, as well as words and body language. Just as the simple words themselves tell only part of the story for humans, so, too, in the insect world, species-specific single- or few-component chemical messaging (i.e. sex pheromones) do not convey all the needed information. Our intonation, tone, intensity, gesturing and posture all combine to allow our fellow humans greater perception and analysis of the larger meaning we are trying to convey. In a comparable way, the chemosensory systems of insects also release mixtures of multiple compounds forming larger patterns for con-specifics to interpret. The communication among insects, like that of humans, has the ability to receive both selectively and collectively. Furthermore, the chemical information, when sent to the central nervous system, is integrated with other information or referred to memorized information, until, finally, it affects behavior. In this chapter, we will focus on the sensory system in cuticular hydrocarbon (CHC) perception.

We can find a variety of chemosensory organs on insect antenna, mouth and other body parts, such as tarsus and wing. In Heterotermes tenuis and Periplaneta americana, some antennal sensory organs have been demonstrated to respond to CHCs by electroantennogram (EAG) or gas chromatography-electroantennographic detection (GC-EAD) (Batista- Pereira et al., 2004; Saïd et al., 2005). In Schistocerca gregaria, it was suggested that stimulation of antennae by CHCs induced intracellular IP₃ synthesis via some chemoreceptors (Heifetz et al., 1997).