To be or not to be: postcubital vein in insects revealed by microtomography

Abstract

To better understand insect evolution, fossils – mainly known by their wings – must be used as terminals in phylogenetic analyses. Such analyses are, however, rarely performed because of a lack of consensus on the homology of venation in insects. Researchers do not agree with the current concept on the exact number and identity of the main veins. Here, we confirm the presence, which has been in question since the early 20th century, of an independent main postcubital vein (PCu vein) between the cubital and anal veins (29 fossil and extant examined orders; > 85% of observed insects). The PCu vein corresponds to the so‐called vein 1A or first anal vein. It is easily identified by the unique shape of its bulla. It may have several branches and be partially fused with the cubital and anal veins. Once the PCu vein was identified, we reconsidered as an example the particular case of the Phasmatodea, showing that extant stick insects have a unique venation among insects, with a reduced median vein and a simple cubital vein adjacent or fused to the PCu vein. This study is a new approach towards resolving wing vein homology issues, crucial for future large‐scale phylogenetic analyses in insects combining extant and extinct taxa.

The Paroecanthini crickets (Orthoptera: Grylloidea: Gryllidae: Oecanthinae) from French Guiana

“…The female is entertained licking the secretions and sometimes biting structures of male metanotum during copulation, meanwhile the male transfers the spermatophore to female. This behavior was already described for other crickets, including Oecanthus Serville, 1831, Truljalia Gorochov, 1985(Podoscirtinae Saussure, 1878 and phalangopsid crickets (Walker & Gurney 1967;Ono et al 2004;Prado 2006;Zefa et al 2008). Usually, metanotal structures are covered by the forewings, as shown in some Paroecanthini crickets (e.g.…”

A hangingfly (Mecoptera, Bittacidae) from the late Oligocene Fossillagerstätte Enspel, Westerwald (SW Germany)

“…We follow the wing venation terminology of Schubnel et al (2020), because it considers the presence of a PCu vein in the wings of the Mecoptera. Byers, 1997 (extant).…”

A new stem Orthoptera (Archaeorthoptera: Oedischioidea) from the Early Permian of the Saar-Nahe Basin, southwest Germany

“…We follow the classification and wing venation terminology of Béthoux and Nel (2002a) and Schubnel et al (2020) Type horizon and locality: Early Permian, Lower Rotliegend, Meisenheim Formation, Jeckenbach Subformation, Niedermoschel black shale (sensu Schindler, 1997), probably Asselian-?Sakmarian Werneburg, 2012, Schneider et al, 2020); Saar-Nahe Basin south of Sitters, Germany.…”