The Waterston’s evaporatorium of Ceraphronidae (Ceraphronoidea, Hymenoptera): A morphological barcode to a cryptic taxon

Jonah M Ulmer,Andrew R Deans,Lars Krogmann,István Mikó

doi:10.3897/jhr.85.67165

Jonah M Ulmer, Andrew R Deans + Show 2 more

Open Access

https://doi.org/10.3897/jhr.85.67165

Copy DOI

Abstract

The Waterston’s evaporatorium (=Waterston’s organ), a cuticular modification surrounding the opening of an exocrine gland located on metasomal tergite 6, is characterized and examined for taxonomic significance within the parasitoid wasp family Ceraphronidae. Modification of the abdominal musculature and the dorsal vessel are also broadly discussed for the superfamily Ceraphronoidea, with a novel abdominal pulsatory organ for Apocrita being discovered and described for the first time. Cuticular modification of T6, due to the presence of the Waterston’s evaporatorium, provides a character complex that allows for genus- and species-level delimitation in Ceraphronidae. The matching of males and females of a species using morphology, a long standing challenge for the group, is also resolved with this new character set. Phylogenetic analysis including 19 Waterston’s evaporatorium related characters provides support for current generic groupings within the Ceraphronidae and elaborates on previously suggested synapomorphies. Potential function of the Waterston’s organ and its effects on the dorsal vessel are discussed.

Highlights

Ceraphronoidea is a cosmopolitan group of parasitoid wasps consisting of two extant families: Ceraphronidae and Megaspilidae
The Waterston’s evaporatorium* (WE) = (Waterston’s organ) (Fig. 3B) is a cuticular specialization corresponding to a putative exocrine gland orifice present on the acrotergite of metasomal tergite 6
We use the name Waterston’s evaporatorium to refer to the cuticular modification following Mikó et al (2009) due to the cuticular structure not falling within the definition of an organ as a multi-tissue structure

Summary

Introduction

Ceraphronoidea is a cosmopolitan group of parasitoid wasps consisting of two extant families: Ceraphronidae and Megaspilidae. The phylogenetic placement of Ceraphronoidea within Apocrita remains unresolved, with current molecular studies indicating a position as sister to Ichneumonoidea (Peters et al 2017) or as sister to Evaniidae, in a clade that is sister to Aculeata (Tang et al 2019). The presence of numerous plesiomorphic traits, including the presence of a median mesoscutal sulcus, well developed pterostigma, two apical spurs of the foretibia, musculated harpes in the male genitalia, and the presence of T10 among others (Gibson 1985; Mikó et al 2013), suggest Ceraphronoidea might retain more plesiomorphic features than most other Apocrita

Methods

Results

Conclusion