The model organism Drosophila melanogaster has become a focal system for investigations of rapidly evolving genital morphology as well as the development and functions of insect reproductive structures. To follow up on a previous paper outlining unifying terminology for the structures of the male terminalia in this species, we offer here a detailed description of the female terminalia of D. melanogaster. Informative diagrams and micrographs are presented to provide a comprehensive overview of the external and internal reproductive structures of females. We propose a collection of terms and definitions to standardize the terminology associated with the female terminalia in D. melanogaster and we provide a correspondence table with the terms previously used. Unifying terminology for both males and females in this species will help to facilitate communication between various disciplines, as well as aid in synthesizing research across publications within a discipline that has historically focused principally on male features. Our efforts to refine and standardize the terminology should expand the utility of this important model system for addressing questions related to the development and evolution of animal genitalia, and morphology in general.

The model organism Drosophila melanogaster has become a focal system for investigations of rapidly evolving genital morphology as well as the development and functions of insect reproductive structures. To follow up on a previous paper outlining unifying terminology for the structures of the male terminalia in this species, we offer here a detailed description of the female terminalia of D. melanogaster. Informative diagrams and micrographs are presented to provide a comprehensive overview of the external and internal reproductive structures of females. We propose a collection of terms and definitions to standardize the terminology associated with the female terminalia in D. melanogaster and we provide a correspondence table with the terms previously used. Unifying terminology for both males and females in this species will help to facilitate communication between various disciplines, as well as aid in synthesizing research across publications within a discipline that has historically focused principally on male features. Our efforts to refine and standardize the terminology should expand the utility of this important model system for addressing questions related to the development and evolution of animal genitalia, and morphology in general.

Egg-laying is one of the key aspects of female reproductive behavior in insects. Egg-laying has been studied since the dawn of Drosophila melanogaster as a model organism. The female’s internal state, hormones, and external factors, including nutrition, light, and social environment, affect egg-laying output. However, only recently has light been shed on certain neurobiological features of egg-laying behavior in both the central and peripheral nervous systems. The central nervous system regulates egg-laying behavior and decision-making, and many studies use fruitless and doublesex, two genes in the sex determination pathway, to identify reproductively important neurons. Neuronal groups like aDNs and pC1clusters modulate egg-laying behavior in the brain, and other neurons like oviINs and oviDNs affect oviposition specifically. In the ventral nerve cord, the abdominal neuromere houses neurons that send information to and from the reproductive tract, including sex peptide abdominal ganglion neurons (SAG) and octopaminergic motor neurons. The reproductive tract itself houses sensory neurons that respond to different aspects of egg maturation and mating, including the male accessory gland products and mechanical stimuli. I conclude this review by summarizing the importance of egg-laying neuronal control in various evolutionary phenomena like cryptic female choice and highlight two Drosophila species and provide intriguing avenues for the future of the field.