A microscopy investigation of the complex problem of infertility of insect hybrids. Studies on the reproductive systems, eggshells, and karyotypes of the representatives of the genus Platymeris (Heteroptera, Reduviidae) and their hybrids.

Hybridisation is still a widely studied phenomenon that allows us to look at some processes differently. However, obtaining fertile hybrids, which we might consider in the long term as precursors of a new species, is still a field that requires research. Much of the research done so far indicates that hybrids are sterile - either sex or both. It is influenced by various mechanisms, both prezygotic and postzygotic reproductive isolation. Thanks to the use of light and transmission electron microscopy, our research has made it possible to understand, at least partially, the causes of infertility in male hybrids resulting from the crossing of two Afrotropical species of the genus Platymeris Laporte, 1833. The analysis of microscopic images showed that one of the possible causes of the infertility of hybrids might be spermatogenesis, during which sperm cells were not formed. In turn, the use of scanning electron microscopy revealed potential abnormalities in the structure of the hybrid eggshell. Moreover, karyotyping analyses suggest possible causes of infertility at the genetic level.