Drivers of diversity and altitudinal distribution of chironomids (Diptera: Chironomidae) in the Ecuadorian Andes / Controladores de diversidad y distribución altitudinal de quironómidos (Diptera: Chironomidae) en los Andes ecuatorianos

Introduction: Chironomids (Diptera: Chironomidae) are the most globally diverse and widely distributed aquatic insects. Despite their prevalence in lotic systems, little is known about the ecology and diversity of tropical species relative to other aquatic insect taxa, particularly at the immature stages. Objective: Characterize chironomid diversity across an elevational gradient in Southwestern Ecuador and water quality parameters associated with their composition. Methods: Samples were collected using a Surber net in forty rivers within four watersheds in the Ecuadorian Andes comprised of montane and dry lowland forest and spanning an elevational gradient of 3 120 m.a.s.l. Various physic chemical variables were measured including oxygen, conductivity, total dissolved solids, temperature, and pH. Results: Generally, environmental variables were strongly correlated with the composition of chironomid communities. Variation in the chriomid communities was most strongly associated with oxygen, conductivity and pH. The presence of Parametriocnemus, Cricotopus f4, Cricotopus sp3., Cricotopus (Isocladius), Oliveiriella, Onconeura, Alotanypus and Pentaneura was associated with lower temperatures, high dissolved oxygen and low conductivity while assemblages of Cricotopus sp., Rheotanytarsus, Tanytarsus, and Chironomus were associated with high conductivity and low concentrations of dissolved oxygen. The RELATE analysis showed that local environmental characteristics are determine the composition of the chironomid community. Conclusions: Similarity among local environmental factors was strongly correlated to similarity among Chironomidae assemblages, especially with variables such as oxygen concentration, pH and conductivity, whose variables are highly correlated to land use and dominant vegetation in the watersheds sampled.

Introducción: Los quironómidos (Diptera: Chironomidae) son los insectos acuáticos de mayor diversidad y distribución mundial. A pesar de su prevalencia en los sistemas lóticos, se sabe poco acerca de su ecología y diversidad, especialmente de especies tropicales en relación con otros taxones de insectos acuáticos, particularmente en etapas inmaduras. Objetivo: Caracterizar la diversidad de quironómidos a través de un gradiente altitudinal en el suroeste de Ecuador, además de identificar los parámetros fisicoquímicos asociados con su composición. Métodos: Las muestras se recolectaron utilizando una red Surber en cuarenta ríos dentro de cuatro cuencas hidrográficas en los Andes Sur del Ecuador, en ecosistemas de bosques montanos y secos de tierras bajas abarcando un gradiente altitudinal de 3 120 m.s.n.m. Se midieron las variables fisicoquímicas: oxígeno, conductividad, sólidos disueltos totales, temperatura y pH. Resultados: En general, las variables ambientales se correlacionaron fuertemente con la composición de las comunidades de quironómidos. La variación en la comunidad de quironómidos se asoció fuertemente con el oxígeno, la conductividad y el pH. La presencia de los géneros Parametriocnemus, Cricotopus f4, Cricotopus sp3, Cricotopus (Isocladius), Oliveiriella, Onconeura, Alotanypus y Pentaneura se asoció a temperaturas bajas, alto oxígeno disuelto y baja conductividad, mientras que Cricotopus sp., Rheotanytarsus, Tanytarsus y Chironomus se asociaron con alta conductividad y bajas concentraciones de oxígeno disuelto. El análisis RELATE mostró que las características ambientales locales determinan la composición de la comunidad de quironómidos. Conclusiones: La similitud entre los factores ambientales locales se correlacionó fuertemente con la similitud entre los conjuntos de Chironomidae, especialmente con variables como la concentración de oxígeno, el pH y la conductividad, cuyas variables están altamente correlacionadas con el uso de la tierra y la vegetación dominante en las cuencas hidrográficas muestreadas.

Clave para la determinación de exuvias pupales de los quironómidos (Diptera: Chironomidae) de ríos altoandinos tropicales / Key to chironomid pupal exuviae (Diptera: Chironomidae) of tropical high Andean streams

. The Chironomidae is a cosmopolitan family of Nematoceran flies with more than 20 000 species described. However the diversity of genera and species of the family in the Andean region beyond the 2 000m.a.s.l are scarcely known. We conducted faunal surveys and biomonitoring research in different streams of Colombia, Ecuador and Peru from May 2005 to October 2011. Based on specimens collections, and a taxonomic key was developed to identify pupae and pupal exuviae of 46 genera of midges (Diptera, Chironomidae) collected from streams at high altitude areas on the Andean tropical mountains. We included illustrations and brief taxonomic descriptions for all genera, of which several ones have not yet been formally described; in this latter case we used the nomenclature of Roback & Coffman (1983). For two genera, Cricotopus and Genus 1, keys to the most common morphospecies were provided. Results showed that in this area the chironomid assemblages are dominated by the members of the subfamily Orthocladiinae (22 genera) followed by the Chironominae (13). Six genera of Tanypodinae were identified, while only three and two genera were present from subfamilies Podonominae and Diamesinae. This key may be very useful for both studies about drift in streams, and for biomonitoring purposes. Rev. Biol. Trop. 62 (4): 1385-1406. Epub 2014 December 01.

Chironomidae es una familia cosmopolita de dípteros nematóceros que comprende más de 20 000 especies descritas. Sin embargo, la diversidad de géneros y especies presentes en la región andina del Neotrópico es poco conocida. Por tal motivo se desarrolló una clave taxonómica para identificar las pupas y exuvias pupales de 46 géneros de la familia Chironomidae presentes en ríos de alta montaña ubicados en la cordillera de los Andes por encima de los 2 000msnm. Se utilizó material de colección obtenido de levantamientos faunísticos y estudios de biomonitoreo en diferentes ríos y quebradas de Colombia, Ecuador y Perú. La clave incluye ilustraciones y breves descripciones taxonómicas de todos los géneros incluyendo algunos que aún no han sido descritos formalmente. Para estos últimos se siguió la nomenclatura usada por Roback & Coffman (1983). Para los géneros Cricotopus y Género 1 se incluyen claves para la determinación de las morfoespecies más comunes. En el ensamblaje de quironómidos de la región altoandina domina la subfamilia Orthocladiinae (22 géneros) seguida por Chironominae (13 géneros), patrón que contrasta con la dominancia de Chironominae en las zonas de menor altura de la región Neotropical. Se encontraron seis géneros pertenecientes a la subfamilia Tanypodinae, mientras que para Podonominae y Diamesinae estuvieron presentes tres y dos géneros respectivamente. Esta clave podría llegar a ser muy útil en estudios de la deriva y programas de biomonitoreo de los ríos altoandinos neotropicales.

Barbadocladius Cranston & Krosch, a new genus of Orthocladiinae (Diptera: Chironomidae) from South America

Barbadocladius n. gen. is erected and described in larval, pupal and adult stages for two species: B. andinus sp. nov. and B. limay sp. nov., from Andean streams. The larva is distinctive by virtue of the very large ventromental 'beard' and the anterior parapods with a 'sleeve' of hooklets in addition to apical pectinate claws. The pupa has hooklets on some tergal and sternal intersegmental membranes. The adult, reported only in teneral specimens has hairy eyes, no antennal apical strong seta, no acrostichals, bare and unmarked wings, cylindrical 4th tarsomere subequal in length to the 5th, pulvilli about half the claw length, and hypopygium with anal point, lacking a virga. Molecular phylogenetic analysis eliminates relationships directly to the Eukiefferiella complex (which also have pupal hooklets), or to the Cricotopus group (adults also with hairy eyes), suggesting instead a sister group relationship to a suite of predominantly austral genera of Orthocladiinae.

Riethia manauara n. sp., an Amazonian Chironomid (Diptera: Chironomidae) from Brazil

One new species of Riethia Kieffer, Riethia manauara n. sp., is described and figured as male, pupa and larva. The generic diagnosis for pupae and larvae are emended. The specimens were collected from water systems in the Amazon Rainforest in northern Brazil.

A new species of Metriocnemus van der wulp (diptera: chironomidae) with a tentative phylogeny of the genus

The male and female of the new species Metriocnemus puna sp. n from the Argentinean Puna are described and illustrated. A parsimony analysis including 24 well-described species of the genus plus the new species based on the adult male was conducted in order to access the phylogenetic position of the new species and to provide the first phylogenetic hypothesis for the genus.

New species of Tanytarsus van der Wulp (Diptera: Chironomidae) from São Paulo state, Brazil

Tanytarsus lenyae sp. n., T. giovannii sp. n., T. fittkaui sp. n. and T. alfredoi sp. n. from São Paulo State (Brazil) are described and diagnosed, the first as adult male and pupa, and the remaining as male, pupa and larva. The species were collected in areas of Cerrado, at the boundaries of São Carlos city. Complete diagnoses and drawings of the species are given. The imagos can be separated from other species of Tanytarsus van der Wulp mainly by differences in the antennal ratio, dorsomedian extension of the eyes, the thorax and wing setation, the shape of anal tergal bands, the anal point armament and the shape of superior volsella, digitus and median volsella. The pupae are characterized by the thoracic horn armament, the arrangement of the precorneals, the shape of anal comb and the abdominal setation. The larvae can be separated by differences in the antennal pedestal, the sclerotization of the second antennal segment, the size of Lauterborn organ pedicels, the shape of the clypeal seta S3 and the sclerotization of the mentum. Apparently, the four new species are not closely related, and the anal point armament alone would be enough to separate one species from the other.

First record of the genus Colosmittia Andersen & Sæther (Chironomidae: Orthocladiinae) from the Neotropical region / Primeiro registro do gênero Colosmittia Andersen & Sæther (Chironomidae: Orthocladiinae) para a região Neotropical

Colosmittia brasileira sp. n. from São Paulo state, Brazil, is described and illustrated based on a male imago. The genus Colosmittia Andersen & Sæther was described based on a single species, C. clavata Andersen & Sæther, from the West Usambara Mountains, Tanzania, East Africa. The discovery of the new species shows that Colosmittia has an Afro-Brazilian distribution pattern.

Colosmittia brasileira sp. n., proveniente do estado de São Paulo, é descrita e ilustrada com base no macho. O gênero Colosmittia Andersen & Sæther foi descrito com base em uma única espécie, C. clavata Andersen & Sæther, de "West Usambara Mountains" na Tanzânia, leste da África. A descoberta de C. brasileira sp. n. indica que o gênero Colosmittia possui padrão de distribuição geográfica do tipo afro-brasileira.

Sponge-dwelling chironomids in the upper Paraná river (Brazil): little known but potentially threatened species / Chironomidae habitantes de esponjas de água doce no alto Rio Paraná (Brasil): espécies pouco conhecidas, mas potencialmente ameaçadas

Neste estudo é apresentada uma lista de espécies de Chironomidae habitantes de esponjas de água doce coletados no Alto Rio Paraná e é chamada a atenção para o problema de substituição de grandes áreas cobertas por esponjas de água doce por bancos da espécie invasora Limnoperma fortunei (mexilhão dourado). Também é descrita uma nova espécie de Oukuriella com base em adulto macho e feita uma descrição informal de uma larva de Chironomidae que provavelmente pertence ao complexo Stenochironomus.

In this paper, we provide a checklist of chironomids living in freshwater sponges in the upper Paraná River (Brazil) and we call attention to the problem of complete substitution of extensive areas covered by freshwater sponges by banks of the invasive alien species Limnoperna fortunei (golden mussel). We describe a new species of Oukuriella based on male adults and also describe an unusual larva of Chironomidae that probably belongs to the Stenochironomus complex.

Redescription of Chironomus salinarius (Diptera: Chironomidae), nuisance midges that emerged in brackish water of Jinhae-man (Bay), Kyongsangnam-do, Korea

Huge numbers of non-biting midges emerged from brackish water which were made at the harbor construction field in Jinhae City, Kyongsangnam-do, Korea in late summer in 2005, and caused a serious nuisance to villagers. The midges were collected and identified as Chironomus salinarius (Kieffer, 1921). Although this species was recorded in Korea for the first time in 1998, the morphological descriptions were so brief and simple. A full redescription is made with detailed illustrations for ecological and control workers of this nuisance midge.

Sobre uma nova espécie neotrópica do gênero Djalmabatista Fittkau, 1968 (Diptera, Chironomidae) / On a new neotropical species of the genus Djalmabatista Fittkau, 1968 (Diptera, Chironomidae)

On a new tropical species of the genus Djalmabatista Fittkau, 1968 (Diptera, Chironomidae) - A new non-biting midge for the genus Djalmabatista Fittkau, 1968 (Tanipodinae, Chironomidae) from Brazil is described

Sobre um novo gênero neotrópico da subfamília Tanypodinae (Diptera, Chironomidae) / On a new neotropical genus of the subfamily Tanypodinae (Diptera, Chironomidae)

On a new tropical genus of the subfamily Tanypodinae (Diptera, Chironomidae) - A new neotropical genus and a new species of a non-biting midge for the subfamily Tanypodinae from Brazil are described. The new genus is near Tanypus Meigen, 1803 and Procladius Skuse, 1889, but differs of both by wings and male terminalia

Sobre uma nova espécie neotrópica do gênero Tanypus Meigen, 1803 (Diptera: Chironomidae, Tanypodinae) / On a new neotropical species of the genus Tanypus Meigen, 1803 (Diptera: Chironomidae, Tanypodinae)

On a new neotropical species of the genus Tanypus Meigen, 1803 (Diptera: Chironomidae, Tanypodinae) - A new neotropical species of the genus Tanypus Meigen, 1803, misidentified by Oliveira (1944) as Tanypus stellatus Coquillett, 1902, is described