Download “lock-and-key” mechanism in the genitalia of the Apamea moths

Is there a “lock-and-key” mechanism in the genitalia of the Apamea moths (Lepidoptera,
Noctuidae)?
Sei-Woong Choi
Department of Ecology and Systematics, Division of Population Biology, P. 0. Box 17 (P.
Rautatiekatu 13), FIN-00014 University of Helsinki, Finland
The existence of a lock-and-key mechanism of insect genitalia was proposed about 150 years ago
by Dufour who examined dipteran species and concluded that genitalia had a great interspecific
variability, and they worked as a mechanical isolating mechanism. After his paper, however, this
hypothesis has become a highly disputable hypothesis in systematics and ecology. One of the
weakest points of this theory is that it is phenetic, because the hypothesis mainly deals with the
morphological characters of the genitalia. In addition to this, it seems that mechanical isolating
mechanisms are often superseded by other mechanisms (e.g. behavioural, physiological).
This study was carried out by examining the correlation of mechanical fitting parts of male and
female internal genital organs of 24 Apamea moths (including 4 ssp.) and the correlation between
body size and male genitalia to test a selection pressure. Furthermore, I made the different
phylogenetic trees with Hennig86 from male and female genital morphological characters and
compared these trees to prove compatibility.
Edward proposed the ‘plural view’ for explaining genital evolution. Different groups of animals
may have totally different selective pressures on their mode of copulation. Similarly, a given
species may be subject to more than one selective pressure promoting genital differentiation.