Change in sex pheromone expression by nutritional shift in male cockroaches

Environmental conditions during sexual maturation impact sexual signal expression, but little is known about how individual histories of changing environmental conditions affect the intensity of male sexual advertisement. We investigated the effects of shifting dietary nutrient composition (protein vs. carbohydrates) in male Nauphoeta cinerea cockroaches on consumption, final lipid reserves, and sex pheromone levels subsequent to completing sexual maturation on a specific diet, at high and low concentration of dietary nutrients. Consumption, lipid reserves, and sex pheromone levels were highly affected by dietary nutrient composition with higher values on carbohydrate-biased diet, and males had significantly higher and lower levels of consumption, lipid reserves, and sex pheromones when shifted to a carbohydrate-biased and a protein-biased diet, respectively, compared with males maintained on either initial diet throughout the experiment. Males shifted to a carbohydrate-biased diet at high nutrient concentration fully recouped their sex pheromone levels, attaining levels that were not significantly lower than those in males maintained on carbohydrate-biased diet at high nutrient concentration throughout the experiment. Our study shows that male sexual display in N. cinerea is plastic and highly affected by present as well as previous dietary conditions. Signaling of adaptive quality through male sex pheromones can therefore vary dynamically within the early adult life of a male in response to the nutritional composition of food that is available to ingest. This contrasts morphological sexual traits in arthropods that are affected during development and are fixed at adulthood