Influence of ecoregion and river type on neotropical Chironomidae (Diptera) from humid mountain to semiarid lowland

Introduction: Chironomidae (Diptera) is the most widespread and abundant aquatic insect family in freshwater ecosystems. Chironomids are considered good indicators of water quality but are seldom identified at the genus level in broad spatial scale studies. Objective: To identify environmental conditions associated with chironomids in an altitudinal gradient. Methods: We compared ecoregions, river types, and seasons, for chironomids in neotropical streams and rivers (18 river sites; 2014-2018; Yungas rainforest and Western Chaco dry forest, Argentina). We used non-metric multidimensional scaling, dissimilarity, envfit analysis and rank-abundance curves. Results: Chironomid "assemblages''matched both ecoregions and river types. However, ecoregions presented a better fit with species composition. The stenothermal taxa of Orthocladiinae were dominant at high elevations and the eurythermal Chironominae in lowland rivers. Altitude, water temperature and conductivity were important. Seasonal differences were smaller than ecoregional differences. Conclusions: Ecoregions, altitude, water temperature and conductivity correlated with chironomid communities. Orthocladiinae were dominant at high elevations and Chironominae in lowland rivers.

Introducción: Chironomidae (Diptera) es la familia de insectos acuáticos más extendida y abundante en los ecosistemas dulceacuícolas. Los quironómidos se consideran buenos indicadores de la calidad del agua, pero rara vez se identifican a nivel de género en estudios de amplia escala espacial. Objetivo: Identificar las condiciones ambientales asociadas a los quironómidos en un gradiente altitudinal. Métodos: Comparamos ecorregiones, tipos de ríos y estaciones para quironómidos en arroyos y ríos neotropicales (18 sitios en ríos; 2014-2018; en un bosque tropical de Yungas y un bosque seco del Chaco Occidental, Argentina). Utilizamos escalamiento no métrico multidimensional, disimilitud, análisis de envfit y curvas de rango-abundancia. Resultados: Los "ensamblajes''de quironómidos coincidieron tanto con las ecorregiones como con los tipos de ríos. Sin embargo, las ecorregiones presentaron un mejor ajuste con la composición de especies. Los taxones estenotérmicos de Orthocladiinae fueron dominantes en las elevaciones altas y los euritermales de Chironominae en los ríos de las tierras bajas. La altitud, la temperatura del agua y la conductividad fueron importantes. Las diferencias estacionales fueron menores que las diferencias ecorregionales. Conclusiones: las ecorregiones, la altitud, la temperatura del agua y la conductividad se correlacionaron con las comunidades de quironómidos. Orthocladiinae fue dominante en los sitios altos y Chironominae en los ríos de tierras bajas.

A new madicolous species of Nilotanypus Kieffer (Diptera: Chironomidae) from Amazon region, northwestern Brazil.

A new species of Nilotanypus Kieffer is described and illustrated based on male, pupa and larva. Nilotanypus yanomami sp. n. was collected at madicolous system in a mountainous region of northern Amazonia. Additionally, the identification key for males is updated and a distribution map for the Neotropical species is provided.

Revision of the Chinese Macropelopia (Diptera: Chironomidae: Tanypodinae), with description of a new species.

The Chinese species of Macropelopia Thienemann are reviewed. A new species belonging to the subgenus Macropelopia, M. (M.) pergrandis sp. n., is described based on the adult male and pupa. Macropelopia grandivolsella Wang, Cheng et Wang and M. rotunda Wang, Cheng et Wang are synonymized with M. (M.) paranebulosa Fittkau and M. (M.) kibunensis (Tokunaga) respectively, based on reexamination of the type materials. Macropelopia galbina Wang, Cheng et Wang is transferred to the genus Brundiniella, and the male holotype is redescribed.

An unusual new species of Pentaneura Philippi (Diptera: Chironomidae) from northeastern Brazil, with an emended diagnosis to the genus.

Pentaneura herbeti sp. nov. is described and illustrated based on male, female, pupa and larva collected in Northeastern region of Brazil. In addition, an amendment in the adult, pupal and larval diagnosis of Pentaneura is provided.

Review of the genus Amnihayesomyia Niitsuma (Diptera: Chironomidae: Tanypodinae), with descriptions of three new species from China.

Three new species of Amnihayesomyia are described from China: A. vittata sp. n. and A. tibetica sp. n. each based on the male and female adults, and A. subflava sp. n. based on the male adult. In addition, a key to the known males of this genus is provided.

Three new neotropical species of Ablabesmyia Johannsen, 1905 (Diptera: Chironomidae).

Three new species of Ablabesmyia are described from Brazil: A. akemiae sp. n. based on the male, female, pupa and larva; A. adamantis sp. n. based on the male, pupa and larva; and A. monticola sp. n. based on the adult male. Ablabesmyia akemiae sp. n. immatures were collected in a small river associated to aquatic vegetation, A. adamantis sp. n. larva was collected in a first order stream associated with accumulated fallen leaves, and adults of A. monticola sp. n. were collected with light-traps, in a mountainous region at about 1000 m altitude.

Procladius travassosi (Oliveira, Messias Silva-Vasconcelos, 1992) regarded as a new junior synonym of Procladius stroudi Roback 1982 (Diptera: Chironomidae: Tanypodinae).

Although recent years have seen increased activity regarding chironomid systematics in the Neotropical region (e.g. Oliveira et al. 2011, 2013, Trivinho-Strixino et al. 2013, 2015, Amora et al. 2015, Parise Pinho 2016, Andersen et al. 2017, Silva Song 2018, Trivinho-Strixino Silva 2018), particularly concerning the subfamily Tanypodinae (e.g. Oliveira Silva 2011, Silva Wiedenbrug 2015, Silva et al. 2014a,b; Siri et al. 2015, Silva Oliveira 2016, Silva Ferrington 2018), when it comes to some species-rich groups, such as Djalmabatista Fittkau, Larsia Fittkau and Procladius Skuse, the taxonomic knowledge remains fragmentary, with only a few species recorded to the Neotropics.

Hábitos alimentarios de quironómidos (Diptera: Chironomidae) en lagos del páramo de Chingaza, Colombia / Feeding habits of chironomids (Diptera: Chironomidae) of paramo lakes, Chingaza, Colombia

Resumen Los lagos tropicales de alta montaña presentan condiciones ambientales únicas donde los quironómidos tienen un papel importante en el funcionamiento del ecosistema. Las características de estos ambientes podrían favorecer el solapamiento de dietas y por ende una alta competencia interespecífica. En este estudio se describen los hábitos alimentarios de géneros de quironómidos, se identifica si los hábitos alimenticios son especializados o generalistas y se analiza el solapamiento en la dieta de los géneros. Entre abril y mayo de 2016 se colectaron larvas de Chironomidae de cuatro lagos del páramo de Chingaza. Se evaluó la dieta de larvas, mediante el análisis de contenido estomacal. Se ubicó cada género en gremios tróficos (carnívoro, detritívoro y alguívoro) y se estimó el solapamiento de las dietas entre los géneros mediante el índice de Pianka. Se colectó un total de 1 003 individuos y se identificaron nueve géneros. Las larvas consumieron principalmente materia orgánica particulada fina (MOPF), algas, fragmentos de macrófitas, macroinvertebrados y tejido animal. La MOPF fue la fuente principal de alimento de detritívoros. El análisis de dietas mostró una alta afinidad de cada género con un único gremio trófico y la mayor parte de los géneros son generalistas en el uso de recursos. En todos los lagos se observaron valores altos de solapamiento en la dieta entre los géneros y los gremios tróficos, principalmente entre los detritívoros. Los resultados sugieren que las larvas de Chironomidae presentan hábitos tróficos bien diferenciados, ocurriendo un moderado solapamiento de dietas entre géneros de detritívoros y carnívoros.

Abstract Tropical high mountain lakes show unique environmental conditions where chironomids play an important role in ecosystem functioning. The characteristics of these environments could favor diet overlap and therefore a high interspecific competition. This study described the dietary habits of chironomid genera, identified whether the dietary habits were specialized or generalist, and analyzed the diet overlap in the genera. Chironomidae larvae were collected from four lakes of the Chingaza paramo during the dry season, between April and May of 2 016. The feeding habits of larvae were evaluated by analyzing gut contents following standard methods. Each genus was assigned to trophic guilds (carnivore, detritivore and algivore) and the diet overlap was estimated using the Pianka's index. A total of 1 003 individuals were collected and nine genera were identified. Larvae consumed mainly fine particulate organic matter (FPOM), algae, macrophyte fragments, macroinvertebrates, and animal tissues. FPOM was the main feeding resource of detritivores. The analysis of diets showed a high affinity of each genus for a single trophic guild and most of the genera were generalist in the use of resources. For all lakes, high levels of diet overlap were observed among genera and trophic guilds, mainly among detritivores. Our results suggested that Chironomidae larvae of these lakes presented well differentiated trophic habits, and showed a moderate diet overlap within detritivores and carnivores. Rev. Biol. Trop. 66(1): 136-148. Epub 2018 March 01.

Monopelopia Fittkau, 1962 (Diptera: Chironomidae) from the Neotropical region: five new species, new records and updated keys.

Five new species of Monopelopia from Brazil are described and illustrated, four of which are based on all life stages and one on adult male and pupa. The immature stages of Monopelopia edentata sp. nov. were collected in bromeliad phytotelmata, while the other species were collected associated with aquatic vegetation. New records for M. boliekae Beck & Beck and M. caraguata Mendes, Marcondes & Pinho are provided, as well as updated identification keys for males and immatures of the Nearctic and Neotropical Monopelopia species.

Two new Neotropical species of Djalmabatista Fittkau (Diptera: Chironomidae).

Two new species of Djalmabatista from northern Brazil are described and illustrated, Djalmabatista patamona sp. nov. based on adult male and pupa and Djalmabatista wapixana sp. nov. based on adult male only.

Notes on the genus Conchapelopia Fittkau (Diptera: Chironomidae: Tanypodinae) from southern China, with description of a new species.

Two interesting species, Conchapelopia togamaculosa Sasa & Okazawa and a new species, Conchapelopia brachiata sp. n., were collected from southern China. The male, pupa and larva of the new species are described, and new distributions of the former species are noted. Although the male of the new species is very distinct from that of the former in the hypopygial median volsella, the pupa and larva stunningly resemble those of the former.

Denopelopia amicitia, a new Tanypodinae from Brazil (Diptera, Chironomidae).

A new species of Denopelopia from Brazil is described based on adult male and pupa. The male of the new species can be distinguished from all other species of the genus by the genitalia and fore-tibial spur morphology. The pupa is very similar to those of Denopelopia atria, but it can be distinguished by the absence of distinct constrictions in the respiratory atrium of the thoracic horn. Generic diagnosis to male and pupa of Denopelopia is emended and keys to male and pupae of known species are provided.

Records of the Genus Paramerina (Diptera: Chironomidae: Tanypodinae) from Eastern Himalaya and Satpura Hill Regions of India.

The pupa and the male imago of Paramerina valida n. sp. and the larva of Paramerina inficia Chaudhuri & Debnath are described and illustrated along with a brief re-description of the adult of P. inficia from the Eastern Himalaya and Satpura hill regions of India. A key to the adult males of the Indian species of the genus Paramerina Fittkau is provided. The notes on ecology of the two species are also provided.

A new species of Djalmabatista Fittkau (Chironomidae, Tanypodinae) from Mato Grosso, Brazil / Uma nova espécie de Djamabatista Fittkau (Chironomidae, Tanypodinae) do Estado do Mato Grosso, Brasil

Djalmabatista scopulata sp. n. is described and figured as male imago, based on material collected in a light trap in Mato Grosso, Brazil. The new species groups with Djalmabatista ivanyae Fittkau, 1968 by having a projection with apical brush on the inner margin of the gonocoxite; it can be separated from D. ivanyae on the banded abdomen.

Djalmabatista scopulata sp. n. é descrita e ilustrada com base no macho adulto de material coletado em armadilha luminosa no Estado do Mato Grosso, Brasil. Esta nova espécie se aproxima de Djalmabatista ivanyae Fittkau, 1968 pela projeção de pelos na margem interna do gonocoxito, da qual pode ser separada com base no padrão de coloração do abdomen.