n-Pentacosane Acts as both Contact and Volatile Pheromone in the tea Weevil, Myllocerinus aurolineatus.

Insect cuticular hydrocarbons (CHCs) play important roles in chemical communication, as well as having ecological and physiological roles. The use of CHCs for mate recognition has been shown in many insect genera, but little is known about their use in the tea weevil Myllocerinus aurolineatus. Here, we provide evidence that CHCs on the surface of sexually mature M. aurolineatus females act as contact sex pheromones, facilitating mate recognition and eliciting copulatory behavior in male weevils. Using gas chromatography-mass spectrometry, we identify n-pentacosane and n-heptacosane as two potential contact pheromone components. Results from arena bioassays showed that n-pentacosane is a component of a contact pheromone of M. aurolineatus. Further results from the Y-tube olfactometer bioassays showed that n-pentacosane also acts as a volatile attractant. Our results greatly improve our understanding of the chemical ecology of M. aurolineatus.