From lanceolate to plate-like: Gross morphology, terminology, and evolutionary trends of the trichophoran ovipositor.

The ovipositor morphology of Trichophora (Hemiptera: Heteroptera) is revisited. Skeletomuscular structure of the ovipositor of selected species and outgroups is documented. Homologies of the structures are established, different homology hypotheses of previous authors are discussed and rejected. The groundplan of the trichophoran ovipositor is reconstructed, apomorphic conditions of each part of the ovipositor are documented. A standard nomenclature is proposed for muscles associated with the ovipositor and extrinsic muscles of the female inner ectodermal genital tracts. Character transformations of the ovipositor are reconstructed via cladistic analysis. The concepts of "lanceolate ovipositor" and "plate-like ovipositor", frequently used in the literature, are discussed; it is concluded that no unambiguous definition of them is possible on a morphological basis, these terms refer merely to evolutionary grades rather than strictly distinct character states. "Plate-like ovipositors" evolved at least four times within Trichophora; they exhibit considerable differences among and within these clades. It is demonstrated that the "M- or W-shaped sclerites" of Pyrrhocoridae and Urostylididae are not homologous: in Pyrrhocoridae they are expansions of the mesal face of the posterior portion of valvifers IX, whilst the superficially similar structures in Urostylididae are infoldings of the ventral rim of the mesal portion of laterotergites IX.