Contributions to the taxonomy and ecology of the <i>Chironomus plumosus</i> sibling species aggregate (Diptera: Chironomidae): the brackish water populations of Tvärminne area, Finland

Abstract

Based on pupal exuviae, two sympatric pupal forms of Chironomus plumosus auctt. are present in the museum materials collected in 1952–1962 from the brackish water near the Tvärminne Biological Station at the northern Baltic Sea. The predominating undescribed type of the pupal exuviae is called here the “Balticmarine species” (possible C. plumosus sensu Linnaeus; direct observations by Linnaeus of Tipula plumosa from freshwater are not on record). Its pupal exuviae and the associated female and male from the Tvärminne population are described. Attempts to find larvae of the genus Chironomus in the sea area of Tvärminne for the renewed and more complete studies failed during the 1980s and 1990s. Only two larvae of the undescribed species of the karyological Chironomus plumosus group were captured. The possible reasons for the supposedly changed environmental conditions are discussed.

Feeding by two closely related species of Chironomus (Diptera: Chironomidae) in south Baltic lagoons, with implications for competitive interactions and resource partitioning

“…Knowledge concerning the autecology of particular species, however, is very limited because of taxonomic difficulties in identifying larvae to species level. This is particularly true for the genus Chironomus (Hirvenoja 2006). Its larvae belong to the dominant group of the zoobenthos of the lagoons located in the south Baltic region (Ezhova et al 2005;Wolnomiejski and Witek 2013;Kornijów and Pawlikowski 2015).…”

Typical types – a swan song? Observations on chironomids in the Linnean collections, and corresponding general considerations

“…on the larval giant chromosome banding patterns), 'recent usage' (whichever way one might define this term) of the name C. plumosus can hardly be seen as anywhere near unanimous and stable. Instead, wherever identification as C. plumosus was not based on karyological determinations, and especially wherever the methods or references used to arrive at such identification were not made sufficiently clear, one cannot determine reliably to which of the species in the Chironomus plumosus sibling species aggregate (e.g., Hirvenoja 2006) the corresponding data actually apply. Incidentally, for the same reason we used to be unable to address the issues -much more interesting to the biologist than matters of nomenclature -which species Linnaeus had encountered, whether it still lives where he found it, why not if it does not, and so on.…”

“…Chironomus tentans Fabricius; paralectotype (ZMUC, Copenhagen), lateral view. The lectotype, also an adult female, has been slide-mounted(Hirvenoja 2006). Photo by M. Kotrba & M. Spies.…”