Malagasy Conostigmus (Hymenoptera: Ceraphronoidea) and the secret of scutes

A new species of the genus Ceraphron Jurine (Hymenoptera: Ceraphronidae) from India

Ceraphron initium sp. nov. is described and illustrated from Nagaland state of India based on male specimens. The genitalia of this new species is studied and compared with the closely related species C. semira Salden & Peters and C. thompsoni (Dalla Torre).

Male genitalia, hierarchical homology, and the anatomy of the bullet ant (Paraponera clavata; Hymenoptera, Formicidae)

The male genitalia of insects are among the most variable, complex, and informative character systems for evolutionary analysis and taxonomic purposes. Because of these general properties, many generations of systematists have struggled to develop a theory of homology and alignment of parts. This struggle continues to the present day, where fundamentally different models and nomenclatures for the male genitalia of Hymenoptera, for example, are applied. Here, we take a multimodal approach to digitalize and comprehensively document the genital skeletomuscular anatomy of the bullet ant (Paraponera clavata; Hymenoptera: Formicidae), including hand dissection, synchrotron radiation microcomputed tomography, microphotography, scanning electron microscopy, confocal laser scanning microscopy, and 3D-printing. Through this work, we generate several new concepts for the structure and form of the male genitalia of Hymenoptera, such as for the endophallic sclerite (=fibula ducti), which we were able to evaluate in detail for the first time for any species. Based on this phenomic anatomical study and comparison with other Holometabola and Hexapoda, we reconsider the homologies of insect genitalia more broadly, and propose a series of clarifications in support of the penis-gonopod theory of male genital identity. Specifically, we use the male genitalia of Paraponera and insects more broadly as an empirical case for hierarchical homology by applying and refining the 5-category classification of serial homologs from DiFrisco et al. (2023) (DLW23) to all of our formalized concepts. Through this, we find that: (1) geometry is a critical attribute to account for in ontology, especially as all individually identifiable attributes are positionally indexed hence can be recognized as homomorphic; (2) the definition of "structure" proposed by DLW23 is difficult to apply, and likely heterogeneous; and (3) formative elements, or spatially defined foldings or in- or evaginations of the epidermis and cuticle, are an important yet overlooked class of homomorphs. We propose a morphogenetic model for male and female insect genitalia, and a model analogous to gene-tree species-tree mappings for the hierarchical homology of male genitalia specifically. For all of the structures evaluated in the present study, we provide 3D-printable models - with and without musculature, and in various states of digital dissection - to facilitate the development of a tactile understanding. Our treatment of the male genitalia of P. clavata serves as a basic template for future phenomic studies of male insect genitalia, which will be substantially improved with the development of automation and collections-based data processing pipelines, that is, collectomics. The Hymenoptera Anatomy Ontology will be a critical resource to include in this effort, and in best practice concepts should be linked.

Conostigmus nankunensis (Hymenoptera: Ceraphronoidea), a new species from China with a long facial sulcus

A new species of the megaspiline genus Conostigmus Dahlbom with a distinct facial sulcus is described and figured from material collected in yellow pan traps. Conostigmus nankunensis Qian and Wang sp. nov., is the fifth species of Conostigmus described from China.

Description of a new species of Conostigmus Dahlbom, 1858 (Hymenoptera: Megaspilidae) from China

One new species of the genus Conostigmus Dahlbom, 1858, Conostigmus xui Cui and Wang sp. nov., from China is described. A key to the known species of Conostigmus from China is provided.

Ants (Hymenoptera: Formicidae) from Miocene Ethiopian amber: filling gaps in the geological record of African terrestrial biota

The Early Miocene (16–23 Mya) amber of Ethiopia constitutes a new source of fossil ants for Africa, where they are otherwise poorly documented. Here we report a diversified assemblage of six subfamilies and at least 19 genera that are still predominantly alive in the Afrotropics today. In this first account, a particular reference is made to the subfamily Dolichoderinae, with the description of two new species: Technomyrmex svojtkai Perrichot & Engel sp. nov. and Ravavy goldmani Boudinot & Perrichot sp. nov. The first is illustrated and described based on synchrotron-radiation microcomputed tomography, and the second represents the first fossil record for the tribe Bothriomyrmecini and Ravavy, a Malagasy and Afrotropical genus that was hitherto monotypic. The ant composition in Ethiopian amber is congruent with the global pattern emerging across ants and showing a Neogene diversification almost exclusively within extant genera.

A new megaspilid wasp from Eocene Baltic amber (Hymenoptera: Ceraphronoidea), with notes on two non-ceraphronoid families: Radiophronidae and Stigmaphronidae

Ceraphronoids are some of the most commonly collected hymenopterans, yet they remain rare in the fossil record. Conostigmus talamasi Mikó and Trietsch, sp. nov. from Baltic amber represents an intermediate form between the type genus, Megaspilus, and one of the most species-rich megaspilid genera, Conostigmus. We describe the new species using 3D data collected with synchrotron-based micro-CT equipment. This non-invasive technique allows for quick data collection in unusually high resolution, revealing morphological traits that are otherwise obscured by the amber. In describing this new species, we revise the diagnostic characters for Ceraphronoidea and discuss possible reasons why minute wasps with a pterostigma are often misidentified as ceraphronoids. Based on the lack of ceraphronoid characteristics, we remove Dendrocerus dubitatus Brues, 1937, Stigmaphronidae, and Radiophronidae from Ceraphronoidea and consider them as incertae sedis. We also provide some guidance for their future classification.

Ceraphron krogmanni (Hymenoptera: Ceraphronidae), a new species from Lower Saxony with unusual male genitalia

Background

Male genitalia phenotypes of Ceraphron (Jurine, 1807) are informative for species delimitation, but due to their minute size, these characters have not been used extensively. Recent developments in visualisation techniques, e.g. confocal laser scanning microscopy and high resolution bright field imaging, allow for more thorough examination of these minute anatomical structures and the development of a robust, male genitalia-based taxonomic system. We also establish a character set, a template, that will facilitate future revisions of these wasps.

New information

Ceraphronkrogmanni sp. nov. is described with outsized male genitalia and multiple diagnostic traits that are unique amongst Ceraphron species.