D3185: Mating effects on Tribolium castaneum alarm pheromone behavioral response

Tribolium castaneum emits an alarm pheromone, consisting of benzoquinones, as a defense function and a stress response to overcrowding. The density of the T. castaneum is a biotic factor that can modulate how the beetles respond to stress and important semiochemicals. Many studies related to density factors focus on the reaction of males and females, but do not focus specifically on mating status. We created colony densities of 10, 100, and 500 adults and removed individuals after a 72-hour mating period. Pupae were then culled out of the jars to be sexed, paired off for mating, or placed alone. The mobility of individual adults in response to concentrations of the synthetic benzoquinone alarm pheromone in the range of 0.05–3 beetle equivalents was assessed using Ethovision coupled with video-tracking. The response was compared to a control containing the solvent (acetone) only. We found that the alarm pheromone upregulated movement and resulted in taxis away from most of the tested stimuli. We also found differential expression of benzoquinones among males and females was impacted due to mating status. This study contributes to our foundational knowledge of the chemical ecology of T. castaneum and provides additional guides on how to interpret T. castaneum dispersal response.