An instance of intergeneric copulation in the family Rhopalidae (Heteroptera): structure, functioning and congruence of the genitalia in two different species from the standpoint of the lock-and-key hypothesis

D.A. Gapon

Abstract. An event of mating between specimens of Corizus hyoscyami and Rhopalus parumpunctatus, registered in the Novgorod Province of Russia is considered. The structure of the aedeagi in their completely inflated state and the female genitalia, as well as the functioning of the genitalia, are described and illustrated. The process of unfolding and swelling of the aedeagi is traced using the method of hydraulic inflation of the membranous parts with glass microcapillaries. The congruence of the genitalia is discussed for each species, and also for the interspecific crosses in both combinations of sexes and species. Structures of insect terminalia are divided into three groups according to their functions: 1) auxiliary structures; 2) structures providing the mutual fixation of the genitalia; and 3) structures directly performing the function of transferring seminal fluid. It is shown that in the considered variants of interspecific crosses, the parts of the genitalia belonging to the second group have almost the same structure and functioning, and most likely cannot perform the function of structural isolation. The structures of the third group have taxon-specific morphological and functioning traits and a high degree of congruence within each species. Schemes of the functioning of the genitalia in interspecific crosses, speculatively showing the impossibility of normal insemination, are proposed.
Key words: genitalia, aedeagus, gynatrium, functioning, congruence, structural reproductive isolation, lock-and-key hypothesis, insects, Heteroptera, Rhopalidae

Zoosystematica Rossica, 2019, 28(1): 3–18  ▪  Published online 7 March 2019   ▪  Open full article  

Electronic supplementary material

    Fig. 13, Fig. 14, Fig. 15, Fig. 16. Additional photographs of mating Corizus hyoscyami (male) and Rhopalus parumpunctatus (female), Novgorod Province. Photographs by E.Yu. Kirtsideli.


Dufour L. 1844. Anatomie générale des diptères. Annales des Sciences Naturelles. Troisième série. Zoologie, 1: 244–264.

Eberhard W.G. 1985. Sexual selection and animal genitalia. Cambridge: Harvard University Press. 244 p.

Gapon D.A. 2001. Inflation of Heteropteran aedeagi using microcapillaries (Heteroptera, Pentatomidae). Zoosystematica Rossica, (2000), 9(1): 157–160.

Gapon D.A. 2007. Structure, function, and morpholo­gical conformity of the male and female genitalia in the true bug genus Pyrrhocoris Fall. (Heteroptera, Pyrrhocoridae). Entomologicheskoe Obozrenie, 86(4): 729–741. (In Russian. English translation: Entomological Review, 2007, 87(9): 1099–1108.

Konstantinov F.V. & Gapon D.A. 2005. On the structure of the aedeagus in shield bugs (Heteroptera, Pentatomidae): 1. Subfamilies Discocephalinae and Phyllocephalinae. Entomologicheskoe Obozrenie, 86(2): 334–352. (In Russian. English translation: Entomological Review, 2005, 85(3): 221–235).

Masly J.P. 2012. 170 years of “lock-and-key”: genital morphology and reproductive isolation. International Journal of Evolutionary Biology, 2012: 1–10.

Mayr E. 1963. Animal Species and Evolution. Cam­bridge: Belknap Press of Harvard University Press. 797 p.

Pluot D. 1970. La spermathèque et les voies genitals femelles des Pyrrhocoridés (Hemiptera). Annales de la Société entomologique de France, 6(4): 777–807.

Putshkov V.G. 1986. Poluzhestkokrylye semeystva Rhopalidae (Heteroptera) fauny SSSR [Bugs of the family Rhopalidae (Heteroptera) of the fauna of the USSR]. Opredeliteli po Faune SSSR, 146. Leningrad: Nauka. 132 p. (In Russian).

Shapiro A.M. & Porter A.H.  1989. The lock-and-key hypothesis: evolutionary and biosystematic inter­pretation of insect genitalia. Annual Review of Entomology, 34:  231–245.

Štys P. 1961. Morphology of the abdomen and fe­male ectodermal genitalia of the Trichophorous Heteroptera and bearing on their classification. In: Strouhal H. & Beier M. (Eds). XI. Internaionaler Kongress für Entomologie, Wien, 17. bis 25: verhandlungen, 1: 37–43. Wien : Organisa­tionskomittee des XI. Internationalen Kongresses für Entomologie.

Ueshima N. 1979. Hemiptera II: Heteroptera. In: John B. (Ed.). Animal cytogenetics, 3(6). Berlin & Stuttgart: Gebrüder Borntraeger. 113 p.

Volume, Year:
Vol. 28. 2019
Vol. 27. 2018
Vol. 26. 2017
Vol. 25. 2016
Vol. 24. 2015
Vol. 23. 2014
Vol. 22. 2013
Vol. 21. 2012
Vol. 20. 2011
Vol. 19. 2010
Vol. 18. 2009
Vol. 17. 2008
Vol. 16. 2007
Vol. 15. 2006
Vol. 14. 2005
Vol. 13. 2004
Vol. 12. 2003
Vol. 11. 2002
Vol. 10. 2001
Vol. 9. 2000
Vol. 8. 1999
Vol. 7. 1998
Vol. 6. 1997
Vol. 5. 1996
Vol. 4. 1995
Vol. 3. 1994
Vol. 2. 1993
Vol. 1. 1992
Suppl. 2. 2018