Neotrolga. Credit Dr Kazunori Yoshizawa, Hokkaido University

Gender bending Brazilian cave insects have reversed genitalia

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Four years ago, Japanese researchers found insects in a Brazilian cave that have reversed sex organs: the females possess penises and the males retain vaginal-like pouches. They now say the two species of cave-dwelling insects have evolved these genitals independently of each other as the size and shape of the penises are significantly different. In order to have sex, the females anchor their penis-like organ into the male vagina-like pouch for 40-70 hours while they receive large volumes of semen from the male.

Journal/conference: Biology Letters

Link to research (DOI): 10.1098/rsbl.2018.0533

Organisation/s: Hokkaido University, Japan

Media Release

From: The Royal Society

Independent origins of female penis and its coevolution with male vagina in cave insects (Psocodea: Prionoglarididae) 

The cave psocid tribe Sensitibillini (Afrotrogla, Neotrogla and Sensitibilla) is of special interest because of its possession of reversed copulatory organs:, i.e., females of Afrotrogla and Neotrogla have a penis-like organ. We present the first molecular phylogeny of Sensitibillini and show that the female penis has evolved twice independently. A correlated evolutionary pattern between male and female genitalia was also detected. This coevolution of genitalia may suggest that sexual conflict or cryptic “male” choice drove the diversity of the female penis, as is the case of male penile diversity in animals with conventional genitalia.


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