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The feeding habits of Chironomidae in hill streams in the pampean region have not been described. In this study, we analyzed the gut contents of this insect family with an aim at establishing their diet in an intermittent stream in the Ventania-Hill system. We sampled three sites with different habitat characteristics (i. e., altitude, substrate type, and current velocity). Of the total of nine taxa were recorded, the only one present at all sites was Corynoneura sp. 1. The food items found were detritus, diatoms, filamentous chlorophytes, euglenophytes, vascular plants, fungi, and animal remains. Most of the taxa could be classified as gathering collectors, with those having a higher proportion of detritus in the gut contents although the guts of Pentaneura nr. cinerea, Cricotopus sp. 1, and Onconeura analiae included high proportions of animal remains. No differences in the feeding habits were attributable to the location in the stream. This research contributes to our understanding of the trophic habits of Chironomidae in an intermittent hill stream system of South America.

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We report a new species of Macropelopia discovered in southern Brazil, with detailed illustrations and descriptions of all life stages. In addition, we provide an identification key specific to males of neotropical Macropelopia species, together with an amendment to the generic diagnosis.

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Studies of the relationships between the temporal variation of biological phenomena and environmental factors are essential to understanding the dynamics of communities. Phenology is a structuring element and, together with voltinism, is related to timing of reproductive activities. The aim of this study is to ascertain the structure and composition of the Chironomid assemblage and its emergence patterns in relation to the environmental variables through the use of the Chironomid pupal exuviae technique using the Neotropical streams as a model. The streams presented similar species compositions. The highest density of pupal exuviae was recorded during spring and the greatest richness in late summer and early autumn. Chironominae presented greater prevalence throughout the year with oscillations for Orthocladiinae and Tanypodinae. Chironominae and Tanypodinae presented emergence peaks in spring-summer and Orthocladiinae in autumn-winter. Rainfall, photoperiod and water and air temperatures structured the Chironomid assemblage, influencing emergence. Univoltine, bivoltine and multivoltine species were recorded. The species presented interspecific synchronization in emergence peaks at different times of the year.

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A new monotypic genus and species of predaceous midge from the southernmost area of the Argentinean Yungas, Yungahelea australis Spinelli and Ronderos, is described and illustrated from male and female adults. It belongs to a group containing the Ceratopogonini genera Parabezzia Malloch, Diaphanobezzia Ingram and Macfie, Spinellihelea Borkent, Grogan and Picado, Leptohelea Wirth and Blanton, and Fittkauhelea Wirth and Blanton. Phylogenetic interpretation indicates that Yungahelea is the sister group of Spinellihelea or the clade composed by Parabezzia and Diaphanobezzia.

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ABSTRACT A new monotypic genus and species of predaceous midge from the southernmost area of the Argentinean Yungas, Yungahelea australis Spinelli and Ronderos, is described and illustrated from male and female adults. It belongs to a group containing the Ceratopogonini genera Parabezzia Malloch, Diaphanobezzia Ingram and Macfie, Spinellihelea Borkent, Grogan and Picado, Leptohelea Wirth and Blanton, and Fittkauhelea Wirth and Blanton. Phylogenetic interpretation indicates that Yungahelea is the sister group of Spinellihelea or the clade composed by Parabezzia and Diaphanobezzia.

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El estudio del material tipo de Chironomus (Polypedilum) griseistriatum Edwards, 1931 de Patagonia nos permite transferir formalmente la especie a Apedilum Townes, 1945 como una nueva combinación, y la cría de un especimen nos permite describir su pupa. Sobre la base de varias larvas pertenecientes a Apedilum colectadas en las proximidades de las localidades en las cuales fueron encontrados los adultos y las pupas, describimos tentativamente el estadio larval. Cápsulas de larvas subfósiles de la misma especie fueron encontradas en la Laguna Stibnite a 46°S en Chile datadas en aproximadamente 2.500 años atrás y en Puerto Blest, Lago Nahuel Huapi a 41°S en Argentina datadas en aproximadamente 2.000 años atrás. Discutimos el hábitat de la especie basados en el material moderno y subfósil. Se provee además de claves de identificación del cuarto estadio larval, pupa y adulto macho

The study of the type material of Chironomus (Polypedilum) griseistriatum Edwards, 1931 described from Patagonia lead us to formally transfer the species to Apedilum Townes, 1945 as a new combination, and a reared specimen allows us to describe its pupa. Based on several larvae belonging to Apedilum collected in the proximity of the localities in which the adults and pupae were found, we tentatively describe the larval stage. Subfossil larval head capsules of the same species were found in Laguna Stibnite at 46°S in Chile dated to about 2,500 years ago and in Puerto Blest, Lago Nahuel Huapi at 41°S in Argentina dated about 2,000 years ago. We discuss the habitat of the species based on both modern and subfossil material. Identification keys to male adult, pupae and fourth instar larvae are also provided

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El estudio del material tipo de Chironomus (Polypedilum) griseistriatum Edwards, 1931 de Patagonia nos permite transferir formalmente la especie a Apedilum Townes, 1945 como una nueva combinación, y la cría de un especimen nos permite describir su pupa. Sobre la base de varias larvas pertenecientes a Apedilum colectadas en las proximidades de las localidades en las cuales fueron encontrados los adultos y las pupas, describimos tentativamente el estadio larval. Cápsulas de larvas subfósiles de la misma especie fueron encontradas en la Laguna Stibnite a 46°S en Chile datadas en aproximadamente 2.500 años atrás y en Puerto Blest, Lago Nahuel Huapi a 41°S en Argentina datadas en aproximadamente 2.000 años atrás. Discutimos el hábitat de la especie basados en el material moderno y subfósil. Se provee además de claves de identificación del cuarto estadio larval, pupa y adulto macho(AU)

The study of the type material of Chironomus (Polypedilum) griseistriatum Edwards, 1931 described from Patagonia lead us to formally transfer the species to Apedilum Townes, 1945 as a new combination, and a reared specimen allows us to describe its pupa. Based on several larvae belonging to Apedilum collected in the proximity of the localities in which the adults and pupae were found, we tentatively describe the larval stage. Subfossil larval head capsules of the same species were found in Laguna Stibnite at 46°S in Chile dated to about 2,500 years ago and in Puerto Blest, Lago Nahuel Huapi at 41°S in Argentina dated about 2,000 years ago. We discuss the habitat of the species based on both modern and subfossil material. Identification keys to male adult, pupae and fourth instar larvae are also provided(AU)

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Three new species of Pseudosmittia Edwards from the Neotropical region, P. satheri, P. larga and P. trapezoidea, are described and figured as males. Allocladiusfortispinatus (Edwards), A. globosus Andersen et al. and A. quadrus Andersen et al. are redescribed on the basis of new material and their geographical distribution updated. A phylogenetic analysis was performed in order to assess the phylogenetic relationships of the new species. As a result, the species P. sœtheri and P. larga are found to be sister species belonging to the angusta group. The species P. trapezoidea is the sister group of the clade ((P. propetropis (P. tropis--P. lamellata)) and belongs to the brevifurcata group sensu lato.

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Trichomycetes, mainly from nonbiting midge (Chironomidae), mosquito (Culicidae) and black fly (Simuliidae) larvae (Insecta: Diptera), are reported from diverse freshwater environments principally from previously unexplored areas of Argentina. Four new species of Harpellales are described: Austrosmittium patagonicum, A. lenticum, Smittium basiramosum and Legeriomyces lichtwardtii. This is the first report of Austrosmittium spp. from the Americas and the first report of a Legeriomyces from South America. Two other species (Simuliomyces sp. and Harpella sp.) are described but not named. Fourteen previously described species were recovered, and their geographical distribution and host ranges have been extended for Argentina, with Sm. phytotelmatum, Stachylina lentica, St. lotica and St. penetralis being new records for the country.

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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.

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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.

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Harpellales (Zygomycota: Trichomycetes) fungi are cosmopolitan obligate inhabitants of the gut of immature insects. A biweekly survey of gut fungi associated with chironomid (Chironomidae: Diptera) larvae living in the impounded water from Eryngium cabrerae (Apiaceae) phytotelmata from Punta Lara forest, Argentina, was done Jan 2003-Dec 2004. Two species of Harpellales were associated with chironomid larvae, Smittium phytotelmatum in the hindgut of Polypedilum sp. and Stachylina lentica in the midgut of both Polypedilum sp. and Metriocnemus eryngiotelmatus. No statistically significant differences were recorded in the prevalence of these Harpellales between seasons. Environmental variables (temperature, rainfall and relative humidity), impounded water volume, pH and chironomid larval density did not have an effect on the prevalence of the Trichomycetes.

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The identity and activity of an entomopathogenic fungus belonging to the Entomophthora muscae species complex and infecting Musca domestica in poultry houses from La Plata, Argentina, is reported. Entomophthora caused natural infections between September 2001 and September 2003. Primary conidia of this fungus were on average 29.5 +/- 1.2 x 23.4 +/- 2.4 microm and contained, on average, 10.5 +/- 0.1 nuclei (range: 7-15) with an average diameter of 4.8 +/- 0.1 microm. This fungus is identified as E. ferdinandii Keller (this specific epithet includes a nomenclaturally required spelling correction); this is a first record of E. ferdinandii in South America and of any member of the E. muscae species complex from flies in Argentina.

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