Pupal Exuviae Research Articles

The Chironomidae (Diptera) fauna of Greece: ecological distributions and patterns, taxalist and new records

For the first time, a faunistic list of the Chironomidae fauna of Greece is presented along with its ecological distribution. Chironomidae larvae and pupal exuviae were collected from 61 locations in mainland Greece during 2006–2008. 76 taxa (genera to species) were recorded. The genera Potthastia , Brillia , Euorthocladius , Synorthocladius , Tvetenia and Xenochironomus are recorded for the first time from Greece. Furthermore, 12 species are new for Greece and five are new for mainland Greece. Chironomidae collected from running waters were analysed with ordination techniques. The results revealed that Chironomidae assemblages were distinguished into three ecoregions with distinct climatic, geological and hydrochemical features. Running waters in Northwestern Greece were generally dominated by species tolerant to water acidification. Chironomids typical of eastern uplands preferred relatively slow current and soft bottom sediments. Assemblages of the southern Peloponnese Peninsula were represented by species of relatively fast flowing, warm streams. However, these are only preliminary results and many more data are needed to justify this ecological distinction of Chironomidae assemblages. This is the first study contributing to the knowledge of a rather neglected insect group of the Greek fauna. It is expected that more species remain to be identified and recorded and future works will contribute to this initial faunal list.

Diversity and distribution of Chironomidae (Insecta: Diptera) of protected areas in North Tunisia

In North Africa seasonal streams called wadi are an unique habitats with serve hydrological and thermal regime. Non-biting midges take an important part of freshwater biodiversity in North Africa. We present new data on the distribution and diversity of Chironomidae in North Tunisia. Larvae, pupal exuviae and adult males of chironomids were collected from a various freshwater ecosystems from May 2005 till April 2006. The aim of this study was to recognize the pattern of midge diversity in North Tunisia to estimate ecological value of running waters in the region. In total, 79 taxa were identified. Nearly all of the taxa were typical representatives of the Palaearctic and Mediterranean complexes. The majority of the investigated sites belonged to the protected areas in North Tunisia, such as the Ichkeul National Park, the Kroumerie Mountains and the El Feija National Park, part of the Intercontinental Reserve of the Mediterranean Biosphere. Altitudinal zonation of the communities composition was found in the lowland (<250 m a.s.l.) and upland zone (>250 m a.s.l.) with maximum of 760 m. Whereas among the data 39 species are recorded from Tunisia for the first time, the species richness of Chironomidae is higher than previously estimated.

Wing geometry of Culex coronator (Diptera: Culicidae) from South and Southeast Brazil

BackgroundThe Coronator Group encompasses Culex coronator Dyar & Knab, Culex camposi Dyar, Culex covagarciai Forattini, Culex ousqua Dyar, Culex usquatissimus Dyar, Culex usquatus Dyar and Culex yojoae Strickman. Culex coronator has the largest geographic distribution, occurring in North, Central and South America. Moreover, it is a potential vector-borne mosquito species because females have been found naturally infected with several arboviruses, i.e., Saint Louis Encephalitis Virus, Venezuelan Equine Encephalitis Virus and West Nile Virus. Considering the epidemiological importance of Cx. coronator, we investigated the wing shape diversity of Cx. coronator from South and Southeast Brazil, a method to preliminarily estimate population diversity.MethodsField-collected immature stages of seven populations from a large geographical area in Brazil were maintained in the laboratory to obtain both females and males linked with pupal and/or larval exuviae. For each individual female, 18 landmarks of left wings were marked and digitalized. After Procrustes superimposition, discriminant analysis of shape was employed to quantify wing shape variation among populations. The isometric estimator centroid size was calculated to assess the overall wing size and allometry.ResultsWing shape was polymorphic among populations of Cx. coronator. However, dissimilarities among populations were higher than those observed within each population, suggesting populational differentiation in Cx. coronator. Morphological distances between populations were not correlated to geographical distances, indicating that other factors may act on wing shape and thus, determining microevolutionary patterns in Cx. coronator. Despite the population differentiation, intrapopulational wing shape variability was equivalent among all seven populations.ConclusionThe wing variability found in Cx. coronator populations brings to light a new biological problem to be investigated: the population genetics of Cx. coronator. Because of differences in the male genitalia, we also transferred Cx. yojoae to the Apicinus Subgroup.

A contribution towards a revision of West Palaearctic Procladius Skuse (Diptera:Chironomidae)

A key is given for the known pupal exuviae of West Palaearctic Procladius (Holotanypus).

Palpomyia ryszardi sp. n. from Peru (Diptera: Ceratopogonidae)

ABSTRACT A new species of the Palpomyia tibialis group, Palpomyia ryszardi, is described from male and female specimens and from their pupal exuviae from material collected in the vicinities of Iquitos in Peruvian Amazonia. The adult is compared with the most similar Neotropical congener, Palpomyia pseudolacustris SPINELLI &amp; DIPPOLITO, and the pupa with the American species Palpomyia subaspera (COQUILLETT). Descriptions are accompanied by photographs and ink illustrations.

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 3,278m asl) compared to the lower altitude streams (below 1,100m 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.

Chironomid (Diptera) species recorded from UK lakes as pupal exuviae

An inventory of chironomid species (Diptera, Chironomidae) data collected from 221 lake basins or reservoirs is detailed together with major physical and chemical characteristics of these waterbodies. Aquatic species of Chironomidae must rise to the water surface for adult emergence. Floating exuviae are transported by wind and water currents to lakeshores. Species data were obtained by collecting lake marginal floating pupal exuviae representing juvenile stages dwelling from across the lake. Among the 450 species found, several were new records for the British Isles.

A new species of Stilobezzia Kieffer from the neotropical region (Diptera, Ceratopogonidae)

A new species from the Neotropical Region, Stilobezzia (Stilobezzia) pseudopunctulata Cazorla & Ronderos, is described and illustrated based on male and female adults and pupal exuviae. Adults were collected in the Argentinian provinces of Chaco, Formosa, Corrientes and Buenos Aires, and in Santa Cruz, Bolivia. The pupa was collected from mats of floating aquatic macrophytes in a lagoon in Ilha da Marchanteria, in the vicinities of Manaus, Brazil. This new species is compared with its similar congener Stilobezzia punctulata Lane, from which it can be mainly distinguished by the wing with only two dark spots, the parameres longer and hook-shaped, the pupal respiratory organ with 11-12 pores and the very short apicolateral processes of the anal segment.

Non-destructive DNA extraction from Chironomidae, including of fragile pupal exuviae, extends analysable collections and enhances vouchering

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Out with the garbage: the parasitic strategy of the mantisfly Plega hagenella mass-infesting colonies of the eusocial bee Melipona subnitida in northeastern Brazil

Between April and June of 2012 mantisflies (Plega hagenella) were found to be extensively parasitizing the nests of two groups of managed colonzies of eusocial stingless bees (Melipona subnitida) in the semi-arid region of northeastern Brazil. The mantisfly larvae developed inside closed brood cells of the bee comb, where each mantispid larva fed on the bee larva or pupa present in a single brood cell. Mature mantispid larvae pupated inside silken cocoons spun in place within their hosts' brood cells then emerged as pharate adults inside the bee colony. Pharate adults were never attacked and killed by host colony workers. Instead, colony workers picked up the pharates and removed them from the nest unharmed, treating them similar to the way that the general refuse is removed from the nest. Adult mantispids subsequently eclosed from their pupal exuviae outside the nest. Manipulative experiments showed that post-eclosion adult mantispids placed back within active bee colonies were quickly attacked and killed. These observations demonstrate that pharate and post-eclosion adults of P. hagenella are perceived differently by colony workers and that delayed adult eclosion is an important functional element in the parasitic life strategy of P. hagenella, allowing adults to escape without injury from the bee colonies they parasitize.

New species of Paratanytarsus Thienemann &amp; Bause 1913 (Diptera: Chironomidae) from the Mediterranean Region (Corsica, southern France and Lebanon)

Three new species of Paratanytarsus are described, from Corsica, southern France and Lebanon, based on the adult males and associated pupal exuviae. These descriptions increase the number of western Palaearctic species in the genus to 23. The pupal exuviae of the new species resemble those of P. bituberculatus (Edwards). Main diagnostic characters as well as additional illustrations of P. bituberculatus are also presented. Characters are given for distinguishing the adult males and the pupal exuviae from other related species. A key to the adult males and pupal exuviae of the described species is provided.doi: 10.5324/fn.v31i0.1372.Published online: 17 October 2012.

Rheotanytarsus dactylophoreus, a new mountain species from streams in the Eastern Pyrenees and Corsica (Diptera: Chironomidae)

The description of Rheotanytarsus dactylophoreus sp. nov. is based on adult males, pharate males and pupal exuviae collected in low and middle mountain streams located in the Eastern Pyrenees and Corsica is presented. The most distinctive character in the adult male is the unusually long, finger-like, digitus and in the pupal exuviae is the thoracic horn which is spinulate laterally (extending from swollen base into tapered apical half). The distribution of R. dactylophoreus sp. nov. indicates that this pyreneocorsican species is a Tyrrhenian faunal element which spread westwards to mountain streams of the Eastern Pyrenees perhaps during the repeated waves of migration from the Paleocene (Montian) till the late Miocene.doi: 10.5324/fn.v31i0.1375.Published online: 17 October 2012.

Time-Efficiency of Sorting Chironomidae Surface-Floating Pupal Exuviae Samples from Urban Trout Streams in Northeast Minnesota, USA

Collections of Chironomidae surface-floating pupal exuviae (SFPE) provide an effective means of assessing water quality in streams. Although not widely used in the United States, the technique is not new and has been shown to be more cost-efficient than traditional dip-net sampling techniques in organically enriched stream in an urban landscape. The intent of this research was to document the efficiency of sorting SFPE samples relative to dip-net samples in trout streams with catchments varying in amount of urbanization and differences in impervious surface. Samples of both SFPE and dip-nets were collected from 17 sample sites located on 12 trout streams in Duluth, MN, USA. We quantified time needed to sort subsamples of 100 macroinvertebrates from dip-net samples, and less than or greater than 100 chironomid exuviae from SFPE samples. For larger samples of SFPE, the time required to subsample up to 300 exuviae was also recorded. The average time to sort subsamples of 100 specimens was 22.5 minutes for SFPE samples, compared to 32.7 minutes for 100 macroinvertebrates in dip-net samples. Average time to sort up to 300 exuviae was 37.7 minutes. These results indicate that sorting SFPE samples is more time-efficient than traditional dip-net techniques in trout streams with varying catchment characteristics.doi: 10.5324/fn.v31i0.1380.Published online: 17 October 2012.

Trait-based surveillance of flood channel effects on the River Thames

An artificial anabranch was opened to the main River Thames by the end of 2001. Chironomid pupal exuviae have been sampled from sites along the main river since 1977 including sites above and below the anabranch. Two sites on the anabranch have also been surveyed since its opening. Long-term surveillance of the chironomid assemblage prior to construction of the anabranch provided a reference state by which its impact could be assessed. Feeding and habitat preferences were attributed to chironomid taxa while additional environmental -tolerance traits were derived from the long-term data of the Thames. Canonical Correspondence Analysis, with spatial variation partialled out, was used to select temporal environmental variables explaining chironomid taxa distribution. Taxa with significant t-values in the regression with selected environmental variables were then included in the subsequent analysis of variance of traits by General Linear Modelling. From 1977 up to 2001 lower Thames sites, above and below the anabranch, showed no significant changes in any of the traits investigated. Four surveys from 2002 to 2009 have revealed some significant changes downstream of the anabranch, both in comparison with before-construction and between sites. These changes suggest the anabranch is providing a sink for poor-quality sediments. Immediately downstream of the anabranch fine sediment-dwelling chironomids have declined within the Thames, chironomids sensitive to ammonia have increased while chironomids tolerant of organic pollution have decreased.doi: 10.5324/fn.v31i0.1360.Published online: 17 October 2012.

Stygocladius multisetosus gen. nov., sp. nov., a rheophilic element, inhabiting basaltic and karstic helocrenes in France and Algeria (Diptera: Chironomidae)

Diagnoses and descriptions of the adults and pupal exuviae of Stygocladius multisetosus gen. nov., sp. nov., are provided based primarily on male and female pharates collected in temporary basaltic and karstic helocrenes in southern France and Algeria. Features on the adult male, female and pupa indicates that it belongs to the Heterotrissocladius group of genera and is probably most closely related to Paratrissocladius Zavřel. The immature stages of the new species are stygobiontic.doi: 10.5324/fn.v31i0.1363.Published online: 17 October 2012.

Redescription of the pupa of Mallochohelea termophila (Diptera: Ceratopogonidae)

The pupal exuvia of Mallochohelea termophila (Spinelli) is redescribed, photographed and illustrated mainly based on the type-series. Pupae of the type-series were collected with forceps from a thermal stream and were attached to rocks about 200 m from the spring head. Pupae from Uruguay were collected with a dipper in lotic and lentic environments. They were reared to adults in the laboratory. This is the first detailed pupal description of a species of Mallochohelea, and the first record of this species from Uruguay. Similarities and differences with the pupae of Neobezzia are provided.

A rapid bioassessment tool for the evaluation of the water quality of transitional waters

The term transitional waters encompasses a wide variety of ecosystems with highly variable environmental conditions and naturally impoverished biological communities. These characteristics have led to a considerable delay in the design and implementation of ecological assessment tools within the European Water Framework Directive. Chironomids are a very important faunal group of transitional waters in terms of relative abundance and species richness. In the present investigation a water quality index based on the chironomid pupal exuviae assemblages was developed. Thirty-seven sites were surveyed along the Catalonian coast (North-East Spain) for their Chironomid pupal exuviae. The index registered a significant response to the causes of eutrophication and its symptoms. Different taxonomic resolution levels were tested and a final tool is proposed based on a genus level identification of chironomid taxa and a classification system based on sensitive/tolerant taxa abundances. The tool has the advantage of being cost-effective (cheap, involving low time-consumption and easy to use) and of integrating all the habitats within the ecosystem.

Transient gut retention and persistence of Salmonella through metamorphosis in the lesser mealworm, Alphitobius diaperinus (Coleoptera: Tenebrionidae)

This study was undertaken to determine the retention of Salmonella through Alphitobius diaperinus metamorphosis and its contribution, through defecation, to external contamination. Insects were exposed to a tagged Salmonella enterica and evaluated for external elimination. (i) Each day for 3 weeks, a filter collected frass from a restrained insect for analysis. (ii) Exposed larvae in a closed container were followed through pupation, and newly emerged adults were examined for their retention of marker bacteria. Exposed adults and larvae produced Salmonella-positive frass for an average of 8 days, ranging from 6 to 11 days and 6 to 12 days, respectively. Nineteen per cent of the larvae carried Salmonella through metamorphosis and eclosion, with 5% of the pupal exuviae being positive as well. Many sources of foodborne pathogens within the poultry production facilities, including reservoir populations, currently go unrecognized. This diminishes the ability of producers to mitigate the transfer of pathogens between animals, humans and the environment. Poultry management standards accept the reutilization of litter. Alphitobius diaperinus survive between flock rotations on the reutilized litter, and it was demonstrated in this study that the Salmonella they carry can survive with them.

Microsatellite-Based Parentage Analysis ofAedes aegypti(Diptera: Culicidae) Using Nonlethal DNA Sampling

To track Aedes aegypti (L.) egg-laying behavior in the field in Iquitos, Peru, we developed methods for 1) sampling DNA from live mosquitoes and 2) high through-put parentage analysis using microsatellite markers. We were able to amplify DNA extracted from a single hind leg, but not from the pupal exuvia. Removal of a leg from teneral females caused no significant changes in female behavioral or life history traits (e.g., longevity, blood feeding frequency, fecundity, egg hatch rate, gonotrophic cycle length, or oviposition behavior). Using a panel of nine microsatellite markers and an exclusion-based software program, we matched offspring to parental pairs in 10 Ae. aegypti test families in which parents originated from natural development sites in Iquitos. By mating known individuals in the laboratory, retaining the male, sampling the female's DNA before release, and collecting offspring in the field, the technique we developed can be used to genotype large numbers of Ae. aegypti, reconstruct family relationships, and track the egg-laying behavior of individual Ae. aegypti in nature.

Diversity and distribution of chironomids (Diptera, Chironomidae) in pristine Alpine and pre-Alpine springs (Northern Italy)

The diversity and distribution of chironomids (Diptera, Chironomidae) were studied in relation to environmental factors in 81 springs under pristine conditions in the Italian Prealps and Alps (Trentino and Veneto, NE-Italy, 46°N, 10-11°E). Each spring was surveyed once, between May and November, in 2005 or in 2007-2008, within 50 m of the spring's source (eucrenal). A total of 173 macroinvertebrate samples were collected, in which 26,871 chironomids (including larvae, pupae, pupal exuviae and adults) were counted. Five subfamilies (Tanypodinae, Diamesinae, Prodiamesinae, Orthocladiinae and Chironominae), 54 genera and 104 species/groups of species were identified. As expected, Orthocladiinae accounted for a large part of specimens (82%), followed by Diamesinae (10%), Chironominae Tanytarsini (6%) and Tanypodinae (2%). Together the Chironominae Chironomini and Prodiamesinae contributed less than 0.05% of the fauna. Larvae represented 97.5% of specimens, mostly juveniles (62.6%). Maximum richness and diversity occurred at intermediate altitudes (ca 900-2100 m a.s.l.). Most taxa were found in a small proportion of sites, and frequencies declined gradually for more widely distributed species. A high number (67%) of rare (= present in less than 10% of sites) taxa were found. Three to 27 taxa were identified per spring. The rheocrene/rheo-helocrene springs were richest in taxa (generally &gt;15 taxa), the mineral spring was poorest, with only three taxa. Most taxa were crenophilous, including lentic, rheobiontic and bryophilous taxa. A Principal Component Analysis (PCA) was performed including 98 taxa. Axes were interpreted calculating the correlation coefficients between site scores and 24 environmental factors. The species with the highest scores were Pseudokiefferiella parva, Corynoneura sp. A, Metriocnemus eurynotus gr., Paratrichocladius skirwithensis and Tvetenia calvescens. Five clusters of sites were identified with K-means analysis on the basis of the first and second PCA axes and a Discriminant Analysis was used to detect environmental factors discriminating the clusters: altitude, canopy cover, hydrological regime, pH, and granulometry as percentage of cobbles and stones. The highly individual nature of springs was highlighted; within the same river basin, between springs and within a single spring. These results suggest that prudent and conservative land management should assume that all springs sheltering such unique faunal assemblages need protection.