Age-dependent changes related to reproductive development in the odor preference of blowflies, Phormia regina, and fleshflies, Boetteherisca peregrina.

We investigated the preference for the odor of decaying meat in a T-maze using female and male blowflies, Phormia regina, with one of two nutritional histories (protein-containing or protein-free diet), and compared them with fleshflies, Boetteherisca peregrina. The preference showed age-dependent changes, which differed according to sex and nutritional history. Females in both nutrition groups showed a high preference for the odor. The preference of protein-fed females showed cyclic variations corresponding to the ovarian cycle, while the protein-deficient group, which never oviposited having immature eggs, did not exhibit cyclic changes and their preference remained high. These results suggest that the preference for the odor may be associated with the ovarian cycle. In males, both nutrition groups showed significant changes with age. The preference of protein-deficient males changed similarly to that of females, whereas protein-fed males were not attracted by the odor. This also suggests that the preference for the odor may be related to reproductive development. With B. peregrina, which has different reproductive natures from P. regina, the age-dependent changes in the preference did not differ so markedly with sex and nutritional history as with P. regina.