Effects of gamma-radiation on the organisation of polytene chromosomes ofGlyptotendipes salinus Michailova (Chironomidae,Diptera)

A series of laboratory experiments onGlyptotendipes salinus were carried out in order to assess cytogenetic effects of different doses of gamma-radiation on polytene chromosomes, isolated from salivary glands. Chrinonomid larvae (III–IV larval stage) were irradiated with doses varying from 0.05 to 1.00 Gy (5–100 rad) and were bred under laboratory conditions until the fourth larval stage. Cytogenetic slides were analyzed for an estimation of occurrence of changes in the organization of the polytene chromosomes caused by gamma-radiation. A specific heterochromatin effect was found in certain chromosomes of the investigated species after 1.00 Gy irradiation. Decondensation of the centromeric heterochromatin and increased functional activity of Balbiany ring 2 were observed in the fourth (G) chromosome. Regression of the nucleolus of the first (AB) chromosome was detected.     

Four‐year successive rearing of Glyptotendipes tokunagai Sasa (Diptera: Chironomidae) under laboratory condition

The dipteran Chironomidae have been commonly used as water quality indicators and toxicity test organisms. Two chironomids, Chironomus riparius Meigan and C. tentans Fabricius, are standard test organisms for toxicity (OECD), but their distribution is limited in Korea. The purpose of this study was to establish a Korean native chironomid species as a toxicity test organism. Glyptotendipes tokunagai Sasa, distributed widely in Korean streams, was selected and reared successively under laboratory conditions for over 30 generations over 4 years. Four G. tokunagai egg masses were collected from the Jungrang stream in Seoul, Korea in April 2007 and introduced to the laboratory for rearing. Room temperature (23.5 ± 3.2°C), larval and adult rearing cages, mating cages, and larval food were appropriately modified from conventional chironomid rearing methods. The number of eggs in an egg mass, hatching rate, and adult body sizes (head width, thorax width, wing width and length, and body length) were monitored every generation. As a result, the number of eggs in an egg mass decreased rapidly in early generations, and then tended to stabilize after the fourth generation (p < 0.05). The mean hatching rate was higher than 75% in all generations. The gender ratio (no. of females/total no. of adults) was 0.24–0.52. The adult body size became significantly reduced in the initial three generations and tended to be stabilized in the following generations (p < 0.05), although it depended on food supply and larval density. This is the first case of chironomid domestication in Korea that has been successfully reared longer than 4 years under laboratory conditions. This reared population of G. tokunagai can be used for various environmental studies such as bioassays, ecological risk assessments, and environmental monitoring.     

Contribution to the knowledge of female west palaearctic Glyptotendipes Kieff. (Diptera, Nematocera, Chironomidae)

The characters of the genitalia of the females of Glyptotendipes glaucus (Meigen, 1818), Glyptotendipes pallens (Meigen, 1804), Glyptotendipes paripes (Edwards, 1929), Glyptotendipes gripekoveni (Kieffer, 1913), Glyptotendipes aequalis (Kieffer, 1922), Glyptotendipes barbipes (Staeger, 1839) and Glyptotendipes salinus Michailova, 1987 are described. A key for the identification of these species is given.The taxonomic status of Glyptotendipes aequalis is discussed.     

Chironomid flies of the genus Glyptotendipes Kieffer (Diptera: Chironomidae) from India with a short account of their biology

Three new species, Glyptotendipes (Glyptotendipes) fumilatus, G. (G.) ingenius and G. (G.) validens are described. A short account of habitat, construction of dwellings, food and feeding of the larva and emergence of the adult has also been appended. A new dichotomous key to the Indian species is provided.     

In situ localization of the evolutionary conserved Cpy/Cty gene in the subfamily Chironominae (Chironomidae, Diptera): establishment of chromosomal homologies

The homologous sites on the salivary gland chromosomes of 13 species from three genera: Chironomus, Glyptotendipes, Kiefferulus have been mapped by means of fluorescent in situ hybridization using the evolutionary conserved gene Cpy/Cty (clone Cla1.1). In all species of genus Chironomus and genus Kiefferulus , the Cty/Cpy gene is located on arm F of chromosome EF. The relocation of the gene among the species of genus Chironomus can be done by simple or complex homozygous inversions which occurred during the divergent evolution of the chromosome of the species. In the genus Glyptotendipes , the Cty/Cpy gene was localized in arm E of chromosome EF. Since the banding patterns of salivary gland chromosomes between genus Chironomus and genus Glyptotendipes cannot be compared directly, in situ hybridization with clone of conservative gene was performed to be established some homologous chromosomes. The results obtained indicate that the chromosome arm F of Chironomus and chromosome arm E of Glyptotendipes may be homologous.     

Qiniella,a new orthoclad genus from China (Diptera: Chironomidae)

Quiniella lii gen. nov., sp. nov. from China is describedas male imago. The genus share bare eyes, wing and squama and extended costa with most members of the Parakiefferiella group sensu S\sgmaelig;ther (1983), and the absence of a scutaltubercle, hump or microtrichial tuft and strongly developedvirga with Krenosmittia Thienemann & Krüger, but isamong other distinguished by a unique trifid gonostylus. This revised version was published online in July 2006 with corrections to the Cover Date.     

Homoeology of banding sequences and centromeres of Glyptotendipes paripes Edwards, 1929 and G. glaucus meigen, 1818 (Diptera, Chironomidae)

The karyotype analysis of the Glyptotendipes paripes Edwards, 1929 from water reservoirs of Saratov region has been conducted. In the studied population, the following combination of banding sequences predominated: A1.1, B1.1 and G1.1. The frequency of larvae with heterozygous inversions was 72.9 %, the average number of heterozygous inversions per specimen was 0.667, and the most frequent heterozygous inversions were B1.2 (39.5%) and D1.2 (29.2%). Localization of centromeres in the polytene chromosomes G. paripes was defined with the help of C-banding. Homoeology of polytene chromosomes of two chironomidae species (G. paripes and G. glaucus Mg.) has been analyzed and redesignation of chromosomes arms G. paripes has been offered: instead of par D--par A, instead of par C--par B, instead of par A--par D and instead of par B--par C.     

Boreoheptagyia phoenicia sp.n. (Diptera,Chironomidae, Diamesinae) from a Lebanese mountain spring

The male imago ofBoreoheptagyia phoenicia sp.n. (Diptera, Chironomidae) is described from material collected in Lebanon-Mount in the headwaters of the coastal river Awwaly.     

Incipient speciation revealed in Anastrepha fraterculus (Diptera; Tephritidae) by studies on mating compatibility, sex pheromones, hybridization, and cytology

It has long been proposed that the nominal species Anastrepha fraterculus is a species complex and earlier studies showed high levels of pre-zygotic isolation between two laboratory strains from Argentina and Peru. Further experiments were carried out on the same populations and on their reciprocal hybrids, including pre- and post-zygotic isolation studies, pheromone analysis, and mitotic and polytene chromosome analysis. A high level of pre-zygotic isolation had been maintained between the parental strains despite 3 years of laboratory rearing under identical conditions. The level of pre-zygotic isolation was reduced in matings with hybrids. There were also differences in other components of mating behaviour. There were quantitative and qualitative differences in the sex pheromone of the two strains with the hybrids producing a mixture. The pre-zygotic isolation barriers were complemented by high levels of post-zygotic inviability and sex ratio distortion, most likely not due to Wolbachia , although there was evidence of some cytoplasmic factor involved in sex ratio distortion. Analysis of polytene chromosomes revealed a high level of asynapsis in the hybrids, together with karyotypic differences between the parental strains. The combined results of the present study indicate that these two strains belong to different biological entities within the proposed A. fraterculus complex.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 152–165.     

Allergens of non-biting midges (Diptera: Chironomidae): a systematic survey of chironomid haemoglobins

Various genera of non-biting midges (Diptera: Chironomidae) possess haemoglobins in larvae and adults. For certain species, these haemoglobins have been implicated in human allergic disease in several countries. The present study confirms and extends observations that haemoglobin is present in many species of Chironomidae, establishes that it is retained from the larval to the adult stage and shows that haemoglobin persists both in live and in dead dry flies. Previous suggestions that Chironomidae should be seen as important environmental and occupational allergens are clearly substantiated.     

The evolutionary history of two species of Orthocladiinae (Diptera: Chironomidae) from Lake Baikal (Eastern Siberia)

The evolutionary history of two species belonging to the genus Orthocladius van der Wulp, 1874 van der Wulp, F.M. (1874), ‘Dipterologische Aanteekneningen’, Tijdschrift voor Entomologie, 17, 109–148. [Google Scholar] (Diptera: Chironomidae) from Lake Baikal was investigated using the mitochondrial gene coding the first subunit of the cytochrome c oxidase (CO1 mtDNA). The phylogenetic analysis indicated that the Baikal Orthocladius species were divided into two well-defined clades where O. (Orthocladius) gregarius Linevitsh, 1970 was a sister species to Palaearctic O. (Orthocladius) nitidoscutellatus Lundstrom, 1915 and the O. (Eudactylocladius) sp. was a sister species to Nearctic O. (Eudactylocladius) subletteorum Cranston, 1998 Сranston, P.S. (1998), ‘Nearctic Orthocladius Subgenus Eudactylocladius Revised (Diptera: Chironomidae)’, Journal of the Kansas Entomological Society, 71(3), 272–295.[Web of Science ®] , [Google Scholar]. Divergence time estimates indicated that these species had been evolving independently for about 18 Ma (Neogene, Early Miocene), while emergence of the most recent common ancestors of the modern O. (Orthocladius) gregarius and O. (Eudactylocladius) sp. was dated to about 3.5 Ma (Neogene, Pliocene). The evolution of Baikal orthoclads occurred from the rheophilic fauna under conditions of global climate change during the geological history of the Baikal Depression in the Tertiary Period.     

Mariambera,a new genus of Orthocladiinae from Brazil (Insecta: Diptera,Chironomidae)

The genus Mariambera is erected based on the males of M. amazonica n. sp. from Amazonas and M. mariae n. sp. from Minas Gerais. The new genus is easily recognized by the distinctive anal point which has a rounded dorsal lobe with microtrichia and a triangular ventral lobe with very strong, marginal setae, in combination with bare eyes and wing membrane, squama with setae, antenna without strong apical seta, and apparently few, short, very weak, hair-like acrostichals in anterior 1/3 of scutum.     

Distribution and production of chironomids (Diptera: Chironomidae) in a shallow, alkaline lake (Neusiedler See, Austria)

From July 1990 to July 1991 the benthic community of the open water zone of Neusiedler See, one of the largest shallow lakes in central Europe, was studied with special reference to the chironomids. Only 16 spp. of chironomids inhabited the sediment of the open water zone. The numerically dominant species were Tanypus punctipennis, Procladius cf. choreus, Microchironomus tener and Cladotanytarsus gr. mancus. Most invertebrates showed a distinct horizontal distribution. Species richness and abundance were highest on muddy and organically rich substrates near the reed belt. Chironomid densities in this area reached 54,000 ind m^–2 and biomass was 2.0 g dw m^–2. The two tanypod species accounted for more than 90% of the standing stock of the macrozoobenthos near the reed belt. The sediment of the open lake and of the eastern part of Neusiedler See was composed of compact clay and sand as a result of the erosion of fine material due to strong waves and currents. Individual densities in these areas were much lower. Production of the numerically dominant species T. punctipennis was estimated using the increment-summation method, whereas production of the remaining species was estimated using an empirically derived multiple regression. Mean annual production of chironomids exceeded 6 g dw m^–2 yr^–1 near the reed belt, but it reached only 0.55 g dw m^–2 yr^–1 in the open lake. These values are rather low compared with other lakes and can be explained by unfavourable sediment conditions due to wave action and by physiological stress due to the water chemistry.     

Cytogenetic characteristics of a population of Chironomus riparius Meigen 1804 (Diptera, Chironomidae) from a polluted Po river station

A population of Chironomus riparius from a Po river station near Moncalieri (a trace-metal polluted station) was studied. In this population was established a great variability of band structure of polytene chromosomes as well as paracentric heterozygous inversions, deletions, deficiencies, partial breaks, diploid chromosome fragments, and changes in functional activity and appearance of heterochromatin. In arms A through F, some bands had an increased size compared to the standard chromosomic map. Some bands appeared in a heterozygous or normal homozygous state or were amplified. In all arms, many condensed stable bands appeared in the decondensed state when compared to the standard map. Asynaptic zones in arms E and G as well as heterozygous Balbiani rings and NORs were established. Very often the 4th chromosome was almost completely heteropycnotic and looded like a pompon chromosome. For the first time in this species, a high frequency of ectopic pairings of different arms was observed. Telomeric regions involved in ectopic pairings had a granular appearance, as did some centromeres. The hypothesis is advanced that such a high frequency of structural rearrangements could be correlated with genomic distribution of specific mobile elements.     

Chironomidae (Diptera) of Baldwin Lake,Illinois, a cooling reservoir

The chironomid fauna of Baldwin Lake, a closed-cycle cooling reservoir for a power plant, was sampled monthly to semi-monthly for one year at four stations, two in the discharge channel and two in the main basin. Qualitative samples were also taken elsewhere and with multiple-plate samplers. Twenty-four species were collected. Annual mean population density was less than 100 larvae m^–2 in the channel, 1037 M^–2 in the main basin. Three species of Tanypodinae formed over 96 percent of the larval population in the main basin: Tanypus stellatus Coquillett, Procladius bellus (Loew), and Coelotanypus concinnus (Coquillett). The principal species on the multiple-plate samplers were Dicrotendipes nervosus (Staeger), Glyptotendipes lobiferus (Say), and Parachironomus monochromus (Wulp). Temperatures of 35°C or more in the channel virtually eliminated the chironomids, whereas temperatures up to 32°C in the main basin increased the number of generations of T. stellatus from the usual two to four at Station 3 and three at Station 4. Station 3 had almost 1,000 degree-days more heat than Station 4.     

The identity of Dactylocladius commensalis (Diptera: Chironomidae) revealed

A new dipteran species, Parapsectra wagneri sp. n. (Chironomidae), is described from emergence traps on Breitenbach, Schlitz, Germany. It differs in antennal ratio and characteristics of the genitalia from the three known species.     

Analysis of chlordane-impacted streams using chironomid pupal exuviae (Diptera: Chironomidae)

A method of rapidly assessing streams and rivers using chironomid pupal exuviae was tested on a chlordane-impacted stream near St. Louis, Missouri. Various concentrations of chlordane were found in sediments of Grand Glaize Creek, most likely resulting from soil runoff around housing and business developments throughout the stream's course. Chironomid pupal exuviae and sediment samples were collected concurrently from Grand Glaize Creek on two separate occasions, once in 1988 and again in 1990. Cluster analysis of samples at sites, based on the percent abundances of taxa within habitats and by subfamilies, produced two distinct clusters; one grouping samples with lower chlordane concentrations and the other grouping samples with higher chlordane concentrations. Further analysis showed a trend towards lower percent abundances of taxa living in depositional and transitional/depositional zones (Chironominae and some Tanypodinae) at the higher chlordane site, while the lower chlordane sites had lower percent abundances of taxa within erosional and erosional/transitional zones (Orthocladiinae and some Tanypodinae). These findings support the hypothesis that taxa living in close association to fine organic sediments will be exposed to higher concentrations of chlordane in the stream and more negatively affected than taxa feeding and living in habitats removed from chlordane-bound sediments. Comparisons from the present study were made to related studies revealing similar patterns among the Chironomidae.