Phylogenetic reclassification and genitalic morphology of the small water strider genus Nesidovelia Andersen & Weir and allied Microveliinae (Hemiptera:Veliidae)

Abstract

Phylogenetic analyses of the Australasian Microveliinae is given, including a reanalysis of Andersen and Weir (2003) dataset and an analysis of a new dataset of 46 morphological characters and 42 taxa. Analyses focused on pregenital, genital and postgenital structures of males and females, including putative male grasping and female antigrasping structures. Phylogenetic analyses resulted in a redefinition of the genus Nesidovelia Andersen & Weir, with Microvelia (Austromicrovelia) and Microvelia (Barbivelia) erected as junior synonyms, and 29 species included in Nesidovelia, with all but the type species in new combination. Nilsvelia gen. nov. is described to include two species, N. milleri and N. ventrospinosa, both formerly assigned to M. (Austromicrovelia). In addition, we report on the recognition of Papuavelia, Pseudovelia and Tanyvelia as valid genera, distinct from Nesidovelia. We diagnose and describe Nilsvelia, and redescribe Nesidovelia, and provide checklists of the included species for both genera.

Group mating in Cretaceous water striders

“…Sexual conflict, specifically sexual coercion, may drive the striking morphological modification and dimorphism [ 21 , 34 , 48 , 49 ]. For example, it is believed that copulatory struggles have driven the evolution of male grasping structures to overcome female resistance in water striders and relatives [ 27 , 33 , 34 , 50 , 51 ]. The new fossils exhibit conspicuous sexual dimorphism in the protibia: (1) the protibia is slightly curved in males ( figure 2 b,d ; electronic supplementary material, figure S4 b,c ), whereas in females, the protibia is straight ( figure 2 e ; electronic supplementary material, figure S2 a ); (2) the protibia of males is armed with 15–17 discontinuous clusters of pegs along the innermost edge, consisting of 2–12 in each cluster ( figure 2 b–d ; electronic supplementary material, figures S2 c,d and S4 b,c ), forming a comb-like structure that is absent in females ( figure 2 e ; electronic supplementary material, figure S2 a ).…”

“…Various specialized grasping traits, including modified pregenital abdominal segments and external genital structures [27,50,[52][53][54], equipped and thickened profemora [2,27,32], and highly specialized antennae and hind legs that form clamps [2,33], have evolved in male gerrid species primarily for grasping and fighting during mating. In the related 'Veliidae', males commonly possess protibial combs as a clasping device [2,34,51]. The primary difference in protibial combs between the new fossil and most 'Veliidae' is that the pegs are continuously distributed in the latter.…”

Oviposition and refractory periods of the small water strider Microvelia horvathi (Heteroptera: Veliidae) after a single mating event

“…Recently, some studies have reported secondary sexual traits, mating behavior, and sexual dimorphism in Veliidae, the sister family of Gerridae (e.g. Cassis et al 2018;Toubiana & Khila 2019). As there are only a few studies related to the reproductive ecology of Veliidae, it is not completely understood.…”