The Cricotopus (Oliveiriella) (Diptera: Chironomidae) of the High Altitude Andean Streams, with Description of a New Species, C. (O.) rieradevallae

The genus Oliveiriella (Chironomidae, Orthocladiinae) was erected by Wiedenbrug & Fittkau (1997). The adults have characteristic black spots on their wings and other characteristics similar to the genus Cricotopus. Pupal skins are very characteristic with strong short spines in the anal lobe instead of setae, while larvae are distinguishable by the long anal papillae and the intense blue color of their body. However, Andersen et al (2013) consider Oliveiriella as a subgenera of Cricotopus. In this paper, using the sequences of the cox1 gene, we conclude that Oliveiriella should be considered a subgenus within Cricotopus, confirming its status in Andersen et al (2013). Furthermore, we describe Cricotopus (Oliveiriella) rieradevallae Prat & Paggi sp. n. from the Saltana river (Ecuador). The adult males, females, and preimaginal stages of the two species of subgenus Oliveiriella known from South America Cricotopus (O.) almeidai n. comb. from Peru, Brazil, and Argentina and Cricotopus (O.) sanjavieri n. comb. from Argentina are compared with those of Cricotopus (O.) rieradevallae sp. n. from Ecuador. The differences allow the distinction of the three species. The cox1 gene reveals that at least three different undescribed species of the same subgenus are present in the high-altitude tropical Andes. The morphology of the available pupae and pupal exuviae reveals the presence of several morphotypes that are candidates to be described as new species. A key used to distinguish these pupal morphotypes is provided, including the three described species. Additionally, the distribution of the subgenus is discussed.

Germline-specific labeling of the somatic chromosomes by protein phosphatase 2A and histone H3S28 phosphorylation in Acricotopus lucidus

Additional chromosomes limited to the germline (=Ks) were established as a special form of germline-soma differentiation in the Orthocladiinae, a subfamily of the Chironomidae (Bauer and Beermann in Z Naturforsch 7b: 557-563, 1952). The Ks together with the somatic chromosomes (=Ss) pass through a complex chromosome cycle with elimination at mitosis and a monopolar migration of all Ks. The dissimilar behavior of Ks and Ss in these exceptional mitoses initiated the search for differential chromosome marks in the orthocladiid Acricotopus lucidus. The search, using immunofluorescence, revealed that in metaphases of male gonial mitoses, and both meiotic divisions, the Ss are fully labeled by protein phosphatase 2A (PP2A) and histone H3S28ph, while in metaphases of somatic cells both marks were detected only at the centromeres of the Ss. In another orthocladiid, Psectrocladius obvius, the same labeling pattern of the Ss as in A. lucidus was established for H3S28ph, but not for PP2A, which was localised solely at the centromeres. In Chironomus nuditaris, a species possessing no Ks, PP2A and H3S28ph signals were always restricted to the centromeres. High levels of H3K4me3, a marker of transcriptionally competent chromatin, were detected on the Ss in metaphases I of C. nuditaris, while in both orthocladiids, the Ss in metaphases I were devoid of H3K4me3 signals. This strongly supports an earlier idea of a silencing of the Ss in male meiosis of A. lucidus suggesting the possibility of extending this concept to the Orthocladiinae. The germline-soma differentiation in A. lucidus is not only made apparent by the occurrence of Ks but also by a germline-specific labeling of the Ss by PP2A and H3S28ph.

Why on the snow? Winter emergence strategies of snow-active Chironomidae (Diptera) in Poland

A long-term study of adult non-biting midges (Chironomidae) active in winter on the snow in mountain areas and lowlands in Poland yielded 35 species. The lowland and mountain communities differed significantly in their specific composition. The mountain assemblage was found to be more diverse and abundant, with a substantial contribution from the subfamily Diamesinae, whereas Orthocladiinae predominated in the lowlands. Orthocladius wetterensis Brundin was the most characteristic and superdominant species in the winter-active chironomid communities in both areas. Only a few specimens and species of snow-active chironomids were recorded in late autumn and early winter. The abundance of chironomids peaked in late February in the mountain and lowland areas with an additional peak in the mountain areas in early April. However, this second peak of activity consisted mainly of Orthocladiinae, as Diamesinae emerged earliest in the season. Most snow-active species emerged in mid- and late winter, but their seasonal patterns differed between the 2 regions as a result of the different species composition and the duration of snow cover in these regions. Spearman's rank correlation coefficient tests yielded positive results between each season and the number of chironomid individuals recorded in the mountain area. A positive correlation between air temperature, rising to +3.5 °C, and the number of specimens recorded on the snow in the mountain community was statistically significant. The winter emergence and mate-searching strategies of chironomids are discussed in the light of global warming, and a brief compilation of most important published data on the phenomena studied is provided.

A review of Norwegian Gymnometriocnemus (Diptera, Chironomidae) including the description of two new species and a new name for Gymnometriocnemusvolitans (Goetghebuer) sensu Brundin

Examination of the syntypes of Metriocnemusvolitans Goetghebuer, 1940 revealed that these specimens belong to the genus Chaetocladius and are not con-specific with Gymnometriocnemusvolitans (Goetghebuer, 1940) sensu Brundin (1956) and Sæther (1983). A literature search showed that Gymnometriocnemuskamimegavirgus Sasa & Hirabayashi, 1993 fits well with the species figured and diagnosed by Brundin (1956) as well as with specimens of this species from Norway. We present arguments for Chaetocladiusvolitans (Goetghebuer) comb. n. and for the use of Gymnometriocnemuskamimegavirgus for Gymnometriocnemusvolitans sensu Brundin. In addition, we provide DNA barcode data that indicate the presence of at least seven Gymnometriocnemus species in Norway of which six are collected as male adults. Two of these, Gymnometriocnemus (Gymnometriocnemus) pallidussp. n. and Gymnometriocnemus (Raphidocladius) autumnalissp. n. are regarded as new to science and diagnosed based on adult male morphology and DNA barcodes. The species Gymnometriocnemus (Gymnometriocnemus) marionensis Sæther, 1969 is re-established and a key to all Holarctic species is provided.

Distribution, Abundance and Molecular Analysis of Genus Barbadocladius Cranston & Krosch (Diptera, Chironomidae) in Tropical, High Altitude Andean Streams and Rivers

The distribution of the genus Barbadocladius Cranston & Krosch (Diptera: Chironomidae), previously reported from Chile to Bolivia, has extended northwards. Larvae, pupae and pupal exuviae of this genus have been found in the high mountain tropical streams of Peru to 9°22'56″, but are restricted to very high altitude streams (altitudes over 3,278 m asl) compared to the lower altitude streams (below 1,100 m asl) in which the genus is reported in Chile and Argentina. Based on morphological studies, both described species in the genus, Barbadocladius andinus Cranston & Krosch and Barbadocladius limay Cranston & Krosch, have been found in Peru as pupae or pupal exuviae. Morphological analysis of the larvae and pupae revealed no differences between the two described species from Patagonia and Peru, which are of similar size and with a similar armament of hooklets and spines in pupal tergites and sternites. However, molecular analysis of larvae and pupae revealed that in Peru, there are at least two different evolutionary lines, one distributed widely and another restricted to one site. Phylogenetic analysis (using cox1 mitochondrial sequences) of all available sequences of Barbadocladius shows that the Chilean and Argentinean material differs from that of Peru. Therefore, a total of four molecular segregates are identified, although morphologically, neither larvae nor the pupae may be differentiated.