Mating of Xenos vesparum (Rossi) (Strepsiptera, Insecta) revisited
Article first published online: 26 JUL 2005
Copyright © 2005 Wiley-Liss, Inc.
Journal of Morphology
Volume 265, Issue 3, pages 291–303, September 2005
How to Cite
Beani, L., Giusti, F., Mercati, D., Lupetti, P., Paccagnini, E., Turillazzi, S. and Dallai, R. (2005), Mating of Xenos vesparum (Rossi) (Strepsiptera, Insecta) revisited. J. Morphol., 265: 291–303. doi: 10.1002/jmor.10359
- Issue published online: 12 AUG 2005
- Article first published online: 26 JUL 2005
- University of Siena (PAR)
- Xenos vesparum;
- hypodermic insemination;
- extragenital reproduction
The controversial mating of the strepsipteran Xenos vesparum was studied to investigate the possible sperm routes for fertilization. The female, which is a neotenic permanent endoparasite of Polistes wasps, extrudes only its anterior region, the “cephalothorax,” from the host abdomen. This region has an opening where both mating and larval escape occur. Observations with scanning and transmission electron microscopy revealed spermatozoa not only in the hemocoel, but also in the “ventral canal” (an extragenital duct peculiar to strepsipteran females) and in the “genital ducts” (ectodermal invaginations connecting the ventral canal to the hemocoel) of recently mated females. Xenos vesparum spermatozoa can reach the oocytes either through the hemocoel as a result of a hypodermic insemination, or by moving along the extragenital ducts, which are later used by first instar larvae to escape. The hypothesis of hypodermic insemination is reconsidered in the light of behavioral and ultrastructural evidence. J. Morphol. © 2005 Wiley-Liss, Inc.