Cryptic species in the nuisance midge Polypedilum nubifer (Skuse (Diptera: Chironomidae) and the status of Tripedilum Kieffer

Abstract

Polypedilum nubifer (Skuse, 1889), originally described from Australia, is an apparently widespread species of Chironomidae (Diptera) that can attain nuisance densities in some eutrophic water bodies. Appropriate management depends upon the identity and ability to distinguish from potential cryptic taxa. A morphological study of larvae, pupae and adults of both sexes confirmed P. nubifer as widely distributed and frequently abundant, but also revealed two previously cryptic species of limited distribution in northern Australia. These species are described as new and illustrated in all stages here. Polypedilum quasinubifer Cranston sp. n. is described from north-west Queensland, Australia and also from Thailand and Singapore. Polypedilum paranubifer Cranston sp. n. is known only from retention ponds of a uranium mine in Northern Territory, Australia. Unusual morphological features of P. nubifer including alternate Lauterborn organs on the larval antenna, cephalic tubules on the pupa and frontal tubercles on the adult head are present in both new species as well. Newly slide-mounted types of Polypedilum pelostolum Kieffer, 1912 (lectotype designated here) confirm synonymy to Chironomus nubifer Skuse, 1889, examined also as newly-slide mounted types. Reviewed plus new evidence does not support recognition of Tripedilum Kieffer, 1921 as a separate taxon; therefore, Tripedilum is returned to junior synonymy with Polypedilum s. str.

Phytophagy in a Polypedilum (Diptera: Chironomidae) species new to Australia and Japan: taxonomy and expanded Asian distribution

“…() and Cranston et al . (), amongst others. A provisional illustrated key to immature stages of Australian Polypedilum (Cranston , ) needs updating following new descriptions (Cranston ) and ongoing updating of coded taxa with formal names (e.g.…”

“…; Cranston et al . ). Many descriptions are of single species based on the adult male alone, but synthesis and reconciliation with immature stages has progressed, e.g.…”

“…Polypedilum is a worldwide genus that includes at least 440 described species (Andersen et al 2015) with an internal classification system of subgenera that is unstable and not fully validated from phylogeny (e.g. Kawai et al 2012;Cranston et al 2016). Many descriptions are of single species based on the adult male alone, but synthesis and reconciliation with immature stages has progressed, e.g.…”

“…In Asia, studies of adults predominate (e.g. Niitsuma 1991;Kawai et al 1998;Zhang et al 2016), but immature stages are included in Tang et al (2014) and Cranston et al (2016), amongst others. A provisional illustrated key to immature stages of Australian Polypedilum (Cranston 1996(Cranston , 2000a) needs updating following new descriptions (Cranston 2000b) and ongoing updating of coded taxa with formal names (e.g.…”

Review of the Japanese Microtendipes (Diptera: Chironomidae: Chironominae), with description of a new species

“…For a morphologically defined but somewhat variable species with such a wide range, we can assume that molecular data will show geographically discrete populations or cryptic species, as with Polypedilum nubifer (Cranston et al 2016). However, sampling across such a wide range is time consuming, impractical and well beyond the scope of this study.…”