A photographic catalog of Ceraphronoidea types at the Muséum national d’Histoire naturelle, Paris – our latest open access publication

Screen Shot 2019-02-28 at 1.41.14 PM

Trietsch C, Mikó I, Deans AR (2019). A photographic catalog of Ceraphronoidea types at the Muséum national d’Histoire naturelle, Paris (MNHN), with comments on unpublished notes from Paul Dessart. European Journal of Taxonomy 0(502). DOI: 0.5852/ejt.2019.502

Abstract.—The majority of Ceraphronoidea (Insecta: Hymenoptera) species were described in the late 1800s and early 1900s, with most of these early descriptions relying on text alone. Few type specimens have been illustrated and even fewer have been photographed, posing a challenge to taxonomists working on the group today. Here, we attempt to remove the barriers obstructing Ceraphronoidea research by creating a photographic catalog of the type specimens present at the Muséum national d’Histoire naturelle (MNHN) in Paris, France. We discuss the history of the ceraphronoid specimens present in the collection and provide comments on unpublished species notes from former Ceraphronoidea taxonomist Paul Dessart. We synonymize Ceraphron myrmecophilus Kieffer, 1913 syn. nov. with Aphanogmus abdominalis (Thomson, 1858) (Hymenoptera: Ceraphronidae) based on the male genitalia morphology, body shape and presence of foveae on the median length of the mesoscutellum. We also report the discovery of the missing male holotype of Ceraphron testaceus (Risbec, 1953) (Hymenoptera: Ceraphronidae) and several potential types of Aphangomus aphidi (Risbec, 1955) (Hymenoptera: Ceraphronidae).

Revision of Trassedia (Hymenoptera: Ceraphronidae), an evolutionary relict with an unusual distribution – our latest publication

Screen Shot 2018-12-11 at 11.24.33 AM

Mikó I, Trietsch C, van de Kamp T, Masner L, Ulmer JM, Yoder MJ, Zuber M, Sandall EL, Baumbach T, Deans AR (2018) Revision of Trassedia (Hymenoptera: Ceraphronidae), an evolutionary relict with an unusual distribution. Insect Systematics and Diversity 2(6): 4 DOI: 10.1093/isd/ixy015

Abstract.—Ceraphronoidea is composed of two, seemingly well-defined families, Ceraphronidae and Megaspilidae. The position of Trassedia Cancemi 1996 within the superfamily is unclear, as this genus shares characteristics of both families. For instance, Trassedia possess both the pterostigma form characteristic of Megaspilidae, and the Waterston’s evaporatorium, a structure unique to Ceraphronidae. Trassedia was known only from a single specimen of T. luapi Cancemi 1996 from Madagascar. We describe nine new species: Trassedia australiensis Mikó and Masner sp. nov. (Australia), Trassedia yanegai Mikó and Trietsch sp. nov. (Thailand), Trassedia brasiliensis Masner and Mikó sp. nov. (Brazil), Trassedia nigra Masner and Mikó sp. nov. (Brazil), Trassedia nigrorufus Mikó and Masner sp. nov. (Panama), Trassedia guianensis Mikó and Masner sp. nov. (French Guiana), Trassedia angustioculus Mikó and Masner sp. nov. (French Guiana), and Trassedia pilosus Masner and Mikó sp. nov. (Costa Rica), and Trassedia gauldi Mikó and Masner sp. nov. (Costa Rica and Brazil). To illuminate the morphological concepts presented here, we provide SR-µCT and confocal laser scanning microscopy (CLSM)-based 3D reconstructions. The Waterston’s organ is sexually dimorphic in Trassedia; it is unpaired in males and paired in females. We describe modifications of the metasoma apex that align with the enlarged hind tarsi, a leg phenotype peculiar to Trassedia and the unique subdivision of the first valvifer. We report the presence of the occipital depression in Trassedia and describe how this structure is involved in a secondary articulation between the head and the mesosoma. We discuss the possible function and phylogenetic relevance of the pterostigma in Ceraphronoidea. Based on its Southern Hemisphere distribution we hypothesize that Trassedia’s presence predates the break-up of Gondwana.

The Insect Collectors’ Code – our latest publication


A vehicle outfitted for fieldwork, primarily to collect Odonata, from a 1959 sampling trip by George H. and Alice F. Beatty. Photo probably by the Beattys

Check out our latest publication, in American Entomologist:

Trietsch C, Deans AR (2018) The Insect Collectors’ Code. American Entomologist 64(3): 156–158 DOI: 10.1093/ae/tmy035

Can’t access the article? See a preprint here: https://scholarsphere.psu.edu/downloads/s1r66j3568 (123KB PDF)

A new megaspilid wasp from Eocene Baltic amber – our latest open access publication


Mikó I, van de Kamp T, Trietsch C, Ulmer JM, Zuber M, Baumbach T, Deans AR. (2018A new megaspilid wasp from Eocene Baltic amber (Hymenoptera: Ceraphronoidea), with notes on two non-ceraphronoid families: Radiophronidae and StigmaphronidaePeerJ 6:e5174 https://doi.org/10.7717/peerj.5174

Abstract.—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 – our latest open access publication

the male genitalia of this wasp species are large and unusual

Ulmer JM, Miko I, Deans AR (2018) Ceraphron krogmanni (Hymenoptera: Ceraphronidae), a new species from Lower Saxony with unusual male genitalia. Biodiversity Data Journal 6: e24173. DOI: 10.3897/BDJ.6.e24173


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

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

Unique extrication structure in a new megaspilid – our latest open access publication

wasp glued to a point made from cardstock

Trietsch C, Mikó I, Notton D, Deans A (2018) Unique extrication structure in a new megaspilid, Dendrocerus scutellaris Trietsch & Mikó (Hymenoptera: Megaspilidae). Biodiversity Data Journal 6: e22676. https://doi.org/10.3897/BDJ.6.e22676

Abstract.—A new species, Dendrocerus scutellaris Trietsch & Mikó (HymenopteraMegaspilidae), is described here from male and female specimens captured in Costa Rica. This species is the only known ceraphronoid wasp with a straight mandibular surface and raised dorsal projections on the scutellum, called the mesoscutellar comb. It is hypothesised that the function of the mesoscutellar comb is to aid the emergence of the adult from the host, especially since the mandibles lack a pointed surface to tear open the pupal case. The authors also provide phenotypic data in a semantic form to facilitate data integration and accessibility across taxa and provide an updated phenotype bank of morphological characters for megaspilid taxonomic treatments. In updating this phenotype bank, the authors continue to make taxonomic data accessible to future systematic efforts focusing on Ceraphronoidea.

Translucent cuticle and setiferous patches in Megaspilidae – our latest open access publication


Trietsch C, Mikó I, Ulmer JM, Deans AR (2017) Translucent cuticle and setiferous patches in Megaspilidae (Hymenoptera, Ceraphronoidea). Journal of Hymenoptera Research 60: 135-156. DOI: 10.3897/jhr.60.13692

Abstract.—All Ceraphronoidea have metasomal patches of translucent cuticle and setae that have never been investigated before, despite their potential behavioral and phylogenetic relevance. To understand the internal and external morphology of these structures, specimens were examined using a broad array of histology-based methods, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) and serial block-face scanning electron microscopy (SBFSEM). For the first time, the setiferous patches are shown to be associated with exocrine glands in Ceraphronoidea. The proposed glandular function is the secretion of pheromones, with the setae above the pore openings serving as a surface for evaporation. The translucent cuticle is morphologically distinct from the setiferous patches; structures resembling lamellar bodies were found underneath the translucent cuticle, and may be associated with photoreceptors or endocrine glands. The locations of translucent cuticle on the metasoma are unique to different families and genera within Ceraphronoidea, and could be useful for inferring phylogenetic relationships. The character distribution suggests that the genera Trassedia and Masner are more closely related to Ceraphronidae than Megaspilidae. We found similar structures containing translucent cuticle in Orussidae and Ichneumonoidea, indicating that these structures are potentially a rich character system for future phylogenetic analysis in Hymenoptera.