The effect of diet and sex on the gustatory behavioral response of the blow fly, Lucilia sericata (Diptera: Calliphoridae), to amino acids associated with decomposition

Blow fly members of the family Calliphoridae, specifically Lucilia sericata, often are important to forensic investigations by aiding in the determination of a post mortem interval, or the time elapsed since the expiration of a living organism. Attracted to the volatile organic compounds (smells) released by decaying material up to a distance of twenty kilometers, L. sericata alters its behavior to fly to and feed on the decaying source of protein. It is known that a protein meal is essential for sexual maturation in female blow flies, but the nutritional role in males has yet to be determined. Despite this fact, it is typical to find both males and females near, and in many cases, on decomposing material. Seeking to understand the role sex and diet in the attraction of blow flies to different nutritive sources, both male and female adult blow flies were raised from emergence on diets of either honey water only, or honey water and a broad-spectrum protein source (bovine liver), after which the flies were tested with decomposition-related amino acids to determine if diet affects behavior. Six decomposition-related amino acids and two sugar sources were tested for gustatory response, utilizing the proboscis extension reflex (PER) assay to determine differences in the behavior of the sexes associated with the stimulus. Results demonstrate that there is a statistically significant age-, sex-, and diet-related difference associated with attraction to, and gustatory interest in the amino acids and sugars tested.