Evolution of reproductive structures for in-flight mating in thynnine wasps (Hymenoptera: Thynnidae: Thynninae).

Thynnine wasps have an unusual mating system that involves concurrent in-flight copulation and nuptial feeding of wingless females by alate males. Consequently, thynnine genitalia play a multifunctional role and have likely been subject to various different selective pressures for both reproductive success and food provisioning. Here, we present a new molecular phylogeny for the Australian Thynninae and use 3D-geometric morphometrics and comparative methods to investigate the morphological evolution of select genital structures across the group. We found significant morphological integration between all male and female structures analysed, which is likely influenced by sexual selection, but also reproductive isolation requirements and mechanical constraints. The morphology of the primary male and female coupling structures was correlated with female body size, and female genitalia exhibited strong negative size allometry. Those male and female coupling structures have evolved at similar evolutionary rates, whereas female structures appear to have evolved a higher degree of morphological novelty over time. We conclude that the unique reproductive strategies of thynnine wasps have resulted in complex evolutionary patterns in their genital morphology, which has likely played a central role in the extensive diversification of the subfamily across Australasia and South America. Our study reinforces the need to treat composite characters such as genitalia by their component parts, and to consider the roles of both male and female reproductive structures in evolutionary studies.

A comprehensive and user-friendly framework for 3D-data visualisation in invertebrates and other organisms.

Methods for 3D-imaging of biological samples are experiencing unprecedented development, with tools such as X-ray micro-computed tomography (µCT) becoming more accessible to biologists. These techniques are inherently suited to small subjects and can simultaneously image both external and internal morphology, thus offering considerable benefits for invertebrate research. However, methods for visualising 3D-data are trailing behind the development of tools for generating such data. Our aim in this article is to make the processing, visualisation and presentation of 3D-data easier, thereby encouraging more researchers to utilise 3D-imaging. Here, we present a comprehensive workflow for manipulating and visualising 3D-data, including basic and advanced options for producing images, videos and interactive 3D-PDFs, from both volume and surface-mesh renderings. We discuss the importance of visualisation for quantitative analysis of invertebrate morphology from 3D-data, and provide example figures illustrating the different options for generating 3D-figures for publication. As more biology journals adopt 3D-PDFs as a standard option, research on microscopic invertebrates and other organisms can be presented in high-resolution 3D-figures, enhancing the way we communicate science.

Species delimitation in asexual insects of economic importance: The case of black scale (Parasaissetia nigra), a cosmopolitan parthenogenetic pest scale insect.

Asexual lineages provide a challenge to species delimitation because species concepts either have little biological meaning for them or are arbitrary, since every individual is monophyletic and reproductively isolated from all other individuals. However, recognition and naming of asexual species is important to conservation and economic applications. Some scale insects are widespread and polyphagous pests of plants, and several species have been found to comprise cryptic species complexes. Parasaissetia nigra (Nietner, 1861) (Hemiptera: Coccidae) is a parthenogenetic, cosmopolitan and polyphagous pest that feeds on plant species from more than 80 families. Here, we implement multiple approaches to assess the species status of P. nigra, including coalescence-based analyses of mitochondrial and nuclear genes, and ecological niche modelling. Our results indicate that the sampled specimens of P. nigra should be considered to comprise at least two ecotypes (or "species") that are ecologically differentiated, particularly in relation to temperature and moisture. The presence of more than one ecotype under the current concept of P. nigra has implications for biosecurity because the geographic extent of each type is not fully known: some countries may currently have only one of the biotypes. Introduction of additional lineages could expand the geographic extent of damage by the pest in some countries.