Preprint Article Version 1 Preserved in Portico This version is not peer-reviewed

Corrections and Additions to Descriptions of Some Species of the Subgenus Orthocladius s. str. (Diptera, Chironomidae, Orthocladiinae)

Version 1 : Received: 7 December 2021 / Approved: 9 December 2021 / Online: 9 December 2021 (08:39:58 CET)

A peer-reviewed article of this Preprint also exists.

Rossaro, B.; Marziali, L.; Magoga, G.; Montagna, M.; Boggero, A. Corrections and Additions to Descriptions of Some Species of the Subgenus Orthocladius s. str. (Diptera, Chironomidae, Orthocladiinae). Insects 2022, 13, 51. Rossaro, B.; Marziali, L.; Magoga, G.; Montagna, M.; Boggero, A. Corrections and Additions to Descriptions of Some Species of the Subgenus Orthocladius s. str. (Diptera, Chironomidae, Orthocladiinae). Insects 2022, 13, 51.

Journal reference: Insects 2022, 13, 51
DOI: 10.3390/insects13010051

Abstract

The larvae of some species of the subgenus Orthocladius s. str. (Diptera, Chironomidae) are here described for the first time with corrections and additions to the descriptions of adult males and pupal exuviae. The identification of larvae is generally not possible without association with their pupal exuviae and/or adult males, so the descriptions here are based only on reared material or on pupae with the associated larval exuviae. Usually, Chironomidae larvae can be separated on the basis of morphometric characters, and the most discriminant characters ones are: 1- the ratio between the width of median tooth of mentum (Dm) and the width of the first lateral tooth (Dl) = mental ratio (DmDl), 2- the ratio between the length of the first antennal segment (A1) and the combined length of segments 2-5 (A(2-5)2-5) = antennal ratio (AR). The shape of mandible, maxilla, and other body parts are almost identical in all the species considered in this study. The larva of Orthocladius (Symposiocladius) lignicola is very characteristic and can be separated by the shape of mentum and the larvae of all the known species of Symposiocladius are characterized by the presence of large Lauterborn organs on antennae and of tufts of setae on abdominal segments. The larvae of Orthocladius (Orthocladius) oblidens and Orthocladius (Orthocladius) rhyacobius can be distinguished from other species basing on their large Dm and to each other by AR. A principal component analysis was carried out using 5 characters: 1- Dm, 2- Dl, 3- length of A1, 4- width of A1 (A1W), 5- combined length of segments 2-5 (A2-5). The most discriminant characters were Dm and A1, confirming that DmDl and AR can be used to separate species at larval stage, but the large superposition of morphometric characters in different species confirms that association with pupal exuviae is in any case needed to identify larvae. In future perspective, the development of reference DNA barcodes from specimens identified by specialists is recommended since possibly the best tool for larvae identification, but association of barcodes with morphotypes is in any case fundamental.

Keywords

Chironomids; taxonomy; morphometry; principal component analysis

Subject

BIOLOGY, Entomology

Comments (0)

We encourage comments and feedback from a broad range of readers. See criteria for comments and our diversity statement.

Leave a public comment
Send a private comment to the author(s)
Views 0
Downloads 0
Comments 0
Metrics 0


×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.
We use cookies on our website to ensure you get the best experience.
Read more about our cookies here.