From the back or front: The courtship position is a matter of smell and sight in Drosophila melanogaster males

Abstract

During courtship, Drosophila melanogaster males usually position themselves behind the target female. To decipher the sensory cues that guide the males to the courting position, we quantitatively analyzed male locomotion traces within a circular observation chamber, at the center of which an immobilized virgin female was placed as a courtship target. Wild-type males preferentially stayed behind the female under not only daylight but also dark conditions, indicating that vision is dispensable for orientation by males. By contrast, olfaction-defective Or83b² homozygous males often positioned themselves in front of a female to court under dark but not daylight conditions. We conclude that vision and olfaction redundantly guide the male fly to move behind the female to perform courtship actions. The visual and olfactory features that provide a male with cues for differentiating between the front and back end of a female are yet to be determined.

Keywords:

• Fruit fly
• innate behavior
• mating
• olfaction
• vision

Acknowledgements

We thank M. Noll for the Or83b² fly strain and M. Suyama for secretarial assistance.

Declaration of interest

The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.

This work was supported by Grant-in-Aids for Scientific Research (Nos. 1802012, 23220007, and 24113502 to D. Y. and 24570081 to K.-I. K.) from MEXT.

Supplementary material available online

Supplementary Figure 1.