An enigmatic Chironomidae (Diptera): first larval description for Nandeva Wiedenbrug, Reiss and Fittkau and evidence for phylogenetic position in Tanytarsini

Peter S Cranston

doi:10.5324/cjcr.v0i32.3308

Abstract

The previously unknown larva of the genus Nandeva Wiedenbrug, Reiss and Fittkau (Chironomidae: Chironominae) is suggested to be a candidate from tropical northern Australia belonging to the tribe Tanytarsini. The basis for the assumption is DNA analysis showing maximum values of Bayesian posterior probability and Bootstrap support for an exclusive sister relationship of the unreared larva with a male of Nandeva from South America. The monophyly of Nandeva has high support as a member of the subtribe Tanytarsina, although its precise relationships within this subtribe lack support. Larval morphology is described and illustrated, and conforms to the subtribe Tanytarsina in tribe Tanytarsini. The historical tempo is discussed in relation to fossils and dating of pertinent nodes and the term ‘pseudo-gondwanan’ is used to described an extant restricted austral range, but with fossils showing a wider past distribution in the north.

Highlights

Since the ‘Holarctic Chironomidae’ project (Wiederholm 1983, 1986, 1989), it has been desirable to incorporate morphology of immature stages in descriptive studies, faunal guides and classifications
Continuing unknown immature stages often are associated with atypical and under-sampled life histories such as terrestrial habitats or immersed wood (e.g. Cranston 2003, 2006) and/or from infrequently surveyed and remote places, such as New Zealand’s subantarctic islands (e.g. Sublette and Wirth 1980). Amongst such genera with the larva unknown yet clearly aquatic is Nandeva Wiedenbrug, Reiss and Fittkau (1988) that is documented from diverse lotic pupal exuviae but until now with no associated larva
Pupal exuviae were intercepted in drift from 6 streams in north-eastern Queensland between latitudes 16° to 18°S

Summary

Introduction

Since the ‘Holarctic Chironomidae’ project (Wiederholm 1983, 1986, 1989), it has been desirable to incorporate morphology of immature stages in descriptive studies, faunal guides and classifications. Continuing unknown immature stages often are associated with atypical and under-sampled life histories such as terrestrial habitats or immersed wood Sublette and Wirth 1980) Amongst such genera with the larva unknown yet clearly aquatic is Nandeva Wiedenbrug, Reiss and Fittkau (1988) that is documented from diverse lotic pupal exuviae but until now with no associated larva. Further undescribed species suggest an extensive distribution in southern America, with an adult known from as far north as Panama. Near simultaneously, this ‘neotropical’ genus was found in tropical northern Australian streams, with the sole species described as Nandeva fittkaui by Cranston (1999). Despite intensive conventional searching using kick and drift nets and breaking immersed wood, no candidate for the larval Nandeva was found

Methods

Results

Conclusion