The karyotype, morphology and ecology of <i>Glyptotendipes aequalis</i> Kieffer (Diptera, Chironomidae)

Abstract

The karyotype, morphology of adult, pupae and larvae, and the ecology of Glyptotendipes aequalis Kieffer (1922) are described from material from Finland, and a neotype from the (probably) original German material is designated. 2n = 8. Ist, IInd and IIIrd chromosomes are metacentric, IVth acrocentric. The IVth chromosome has a nucleolus and a Balbiani ring. G. aequalis is karyologically closely related to G. caulicola, differing by a simple inversion step.

Notes and recommendations on taxonomy and nomenclature of Chironomidae (Diptera)

“…Some of the latter may be related to body size -the holotype being at the very short end of the range of exuvial lengths reported by Hirvenoja & Michailova -but this does not cover differences such as the absence of the "extensive small granulation" (Langton & Visser, 2003) on the thorax. Also noteworthy here is an apparent discrepancy in adult male morphology: Hirvenoja & Michailova (1991) and Contreras-Lichtenberg (2001) describe the superior volsella as apically strongly hooked (and apparently invariably so), whereas Kieffer (1922d) gave it with the "distal half weakly curved, apex slightly narrower". In the original determination letter (at ZSM) exchanged with Thienemann, Kieffer placed G. aequalis "close to C. scirpi " Kieffer, 1915, for which Contreras-Lichtenberg (2001 indeed describes the superior volsella as only "curv-ZOOTAXA ing", not hooked, and "distally abruptly narrowed".…”

“…Glyptotendipes (Caulochironomus) aequalis (Kieffer). Hirvenoja & Michailova (1991) redescribed G. aequalis based in part on the sole pupal exuviae reported by Lenz (in Goetghebuer & Lenz, 1937-1962, and designated this specimen as the neotype. However, this exuviae undoubtedly is part of the holotype, as evidenced by Thienemann's unique sample identifier ("Insula") on the label with the exuviae, and a remark on his corresponding register sheet (at ZSM) that only two adults emerged from this sample rearing: one G. aequalis, the other an Endochironomus.…”

“…However, this exuviae undoubtedly is part of the holotype, as evidenced by Thienemann's unique sample identifier ("Insula") on the label with the exuviae, and a remark on his corresponding register sheet (at ZSM) that only two adults emerged from this sample rearing: one G. aequalis, the other an Endochironomus. Hirvenoja & Michailova (1991: fig. 1G, and p. 93) placed this exuviae at one end of a rather wide range of morphological variation, but saw no grounds for taxonomic separation anywhere in their material.…”

“…On the other hand, the uniformity in their larval karyology results could be due to the corresponding specimens having come from only one of the several populations represented in their morphological data. Contreras-Lichtenberg (2001) and Langton & Visser (2003) apparently did not examine this holotype for their interpretation of G. aequalis, and they do not discuss the issue of variation raised by Hirvenoja & Michailova (1991). Some of the latter may be related to body size -the holotype being at the very short end of the range of exuvial lengths reported by Hirvenoja & Michailova -but this does not cover differences such as the absence of the "extensive small granulation" (Langton & Visser, 2003) on the thorax.…”