On the distribution and habitat use of the sub-Antarctic fly Hyadesimyia clausa Bigot (Diptera, Tachinidae) according to citizen science.

Hyadesimyia clausa Bigot is a morphologically striking tachinid that inhabits the Sub-Antarctic Ecoregion of the Magallanes Region in Chile and Tierra del Fuego province in Argentina. Much of the distributional information about this species is restricted to the Cape Horn islands, which have extreme environmental conditions, but the species' natural history, range limits, and habitat use have never been described or confirmed. Our goals were to describe the distributional limits of this sub-Antarctic fly with the help of citizen science and use this information type to describe this tachinid's habitat use and potential biological interactions with nonvascular and vascular flora. We found that citizen science significantly increased our understanding of the extent of occurrence, expanding the known distributional range by 195 km to the north and 153 km to the west. On the contrary, the values for the area of occupancy were not significant, but the occupancy overlap between different records was very low. We confirmed that H. clausa's habitat uses peatlands and although we have not provided evidence of pollination or movement of spores, we hypothesized, that the walking activity of H. clausa could help move sperm from mosses and pollen from the flowers of vascular plants, so they could act as potential pollinators. Citizen science can reduce and eliminate some scientific knowledge shortfalls and propose new ecological questions that could increase our knowledge of extreme ecosystems.

Taxonomic review of the genus Aldrichiopa Guimares, 1971 (Diptera: Tachinidae) with notes on antennal morphology and description of a new species.

A redescription of the genus Aldrichiopa Aldrich, 1934 (Diptera: Tachinidae) is provided and a new species, Aldrichiopa serrata Torres-Domnguez & Mulieri sp. nov. is described from specimens collected in Argentina and Chile. A detailed morphological description of the egg, first instar larva, and adult male and female including terminalia are presented for the first time. Exhaustive photographic records, scanning electron microscopy images, morphological detail of antennal ultrastructure, and updated geographic distributions are provided for the two species of the genus, Aldrichiopa coracella (Aldrich) and A. serrata sp. nov. An identification key based on males is provided. The taxonomic placement of Aldrichiopa to subfamily and tribe is discussed and information on the hosts of this genus of small tachinid flies is compiled.

Description of three new species of Dexosarcophaga (Diptera, Sarcophagidae) from Brazil with new information on synonyms and filling gaps in species distribution.

Three new species of DexosarcophagaTownsend, 1917 are described based on male specimens collected in Brazil, Dexosarcophaga sinoisp. nov., Dexosarcophaga autisferasp. nov., and Dexosarcophaga clavissp. nov. Male morphology is represented by photographs and detailed illustrations of terminalia. Dexosarcophaga carvalhoi (Lopes, 1980), Dexosarcophaga globulosaLopes, 1946, Dexosarcophaga limitata (Lopes, 1975), Dexosarcophaga paulistana (Lopes, 1982b), and Dexosarcophaga petraSantos, Pape and Mello-Patiu 2022 are recorded for the first time in Argentina. Also, Dexosarcophaga lenkoiLopes, 1968, Dexosarcophaga montana (Lopes, 1975), and Dexosarcophaga transitaTownsend, 1917 have their distribution expanded with new records. Dexosarcophaga transita is considered a senior synonym of Dexosarcophaga chaetosaBlanchard, 1939syn. nov., Dexosarcophaga itaquaDodge, 1966syn. nov., and Dexosarcophaga lopesiDodge, 1968syn. nov. With the addition of the new species and the new synonymies proposed, Dexosarcophaga now contains 58 species, of which 10 are recorded in Argentina and 35 in Brazil.

Improving geographic distribution data for a putatively extinct species, a test case with a disappeared fly.

Global biodiversity loss by anthropogenic impacts is an under-recognized form of global environmental change. Global defaunation is still poorly documented in the case of insects, showing a significant decrease in populations and diversity. The blowfly Neta chilensis (Walker 1837) is poorly known and presumed to be confined to southern-South America, with an unclear distributional pattern. It was last collected in 1984. We aimed, through Ecological Niche Models, to identify regions highly suitable for N. chilensis; to test the suitability of regions with doubtful records; to understand the impact that climatic change and human activities have had; and to identify regions with high chances to find it. We compiled 130 presence records from Argentina and Chile and 117 localities where it was sought but not found between 1987 and 2018. Results indicate that suitable conditions are restricted to southern and central Chile and to southwestern Argentina, that doubtful records are predicted in unsuitable areas, that N. chilensis occupies a narrow niche and that its decline is not mainly caused by climate changes but more probably to habitat loss and to the biological invasion. We identified two regions where the chances of finding the species are higher in the case that it is not extinct already.

Effect of Vegetation Types on Sarcophagidae (Diptera) in Ciervo de los Pantanos National Park, a Natural Remnant in a Highly Endangered Landscape.

Species diversity can be affected by the structure of vegetation, which may vary in height, density, and distribution of trees, shrubs, and other plant types, configuring different types of habitats. In this study, we evaluated the diversity of sarcosaprophagous Sarcophagidae communities inhabiting the remnant representative habitats protected in Ciervo de los Pantanos National Park: grasslands, forests, and wetlands. We hypothesized that the abundance and diversity of flesh flies would be higher in the grasslands and wetlands than in the forest patches. Samplings were carried out in each habitat type using baited traps during the four seasons in 2015, 2016, and 2019. We collected 585 sarcophagid flies of 17 species. Fifteen species were recorded in grasslands, twelve in the wetlands, and seven in the forests, Tricharaea (Sarcophagula) occidua (Fabricius) (Diptera: Sarcophagidae) being the most abundant (58.3% of the total sample). As expected, the highest abundance was recorded in grasslands whereas the lowest was found in forests. In addition, flesh fly abundance was affected by season. Sarcophagid assemblages differed between habitats and the overall dissimilarity was mainly explained by nestedness. This study provides important information about sarcosaprophagous sarcophagid flies in a little-studied protected natural area in Argentina, which is fundamental for their conservation and useful in forensic investigations.

Seasonal Fluctuations in Sarcophagidae (Diptera: Calyptratae) Assemblages in the Humid Chaco Ecoregion, Argentina.

The seasonal fluctuations of flesh fly (Diptera: Sarcophagidae) assemblages were investigated from March 2015 to February 2016 in five habitat types in the Humid Chaco ecoregion, Chaco Province, Argentina. Three of the habitats were anthropized: an urban area, a cattle farm, and an alfalfa crop; and two were natural: a savanna and a forest. Flesh flies were collected monthly at 25 sampling points, five per habitat. In total, 5,790 male specimens comprising 55 species distributed in 15 genera were collected. The assemblage composition of flesh flies in each habitat and season was analyzed in terms of abundance, species richness, and diversity. In addition, the correlation between these community parameters and climatic factors (precipitation 7 and 14 d before samplings, temperature, and relative humidity) were evaluated in each habitat. The highest abundance and species richness of Sarcophagidae were registered in May (autumn) and June (winter), respectively. The lowest diversity values were observed between August and September (end of winter and early spring) in all habitats. However, flesh flies were present and well represented (in terms of species richness) throughout the year in all habitat types. Fluctuations in the abundance of the most abundant species collected were analyzed. The climatic factors were correlated with diversity and species richness in the urban, cattle farm, and savanna habitats. This study revealed that flesh fly assemblages differed temporally between different types of habitats in accordance with climatic factors and microclimate conditions.

The Effect of Anthropization on Sarcophagidae (Diptera: Calyptratae) Community Structure: An Assessment on Different Types of Habitats in the Humid Chaco Ecoregion of Argentina.

Sarcophagidae (Diptera) are of great interest from a veterinary, medical, and forensic viewpoint, and are potential bioindicators for environmental impact assessments. In this study, we evaluated changes in abundance, species richness, and diversity of flesh flies in different habitat types in the Humid Chaco ecoregion of South America: 1) anthropized habitats: urban, cattle farm, and alfalfa crop, and 2) natural habitats: savanna and forest. We hypothesized that sarcophagid fly community parameters are affected by the anthropization and that spatial turnover will contribute more to the overall beta diversity than nestedness between habitats. In each habitat, samplings were conducted monthly from March 2015 to February 2016 in 25 sites, 5 per habitat, totaling 300 independent samples at the end of the study. We collected 5,790 Sarcophagidae (55 species). Community parameters of Sarcophagidae were evaluated and compared. The ecological effects of anthropization and habitat type were observed in the present study. As expected, our results showed the highest abundance, species richness, and diversity in the savanna and forest habitats (natural), whereas the lowest values were registered in the urban and alfalfa crop habitats, supporting the hypotheses of anthropization as the main driver of diversity loss. In addition, sarcophagid assemblages differed between all habitats and the overall dissimilarity was structured by spatial turnover. The main conclusion of this research is that flesh fly community structure is greatly affected by anthropization and habitat type, and this would be related to canopy cover and microclimate conditions of each environment.

Calliphoridae (Diptera) in Human-Transformed and Wild Habitats: Diversity and Seasonal Fluctuations in the Humid Chaco Ecoregion of South America.

A temporal study of the Calliphoridae fauna was conducted in five different types of habitats in the Humid Chaco ecoregion: an urban settlement, a cattle farm, an alfalfa crop, a savanna, and a forest. Research was carried out to analyze 1) how the species composition of blow fly communities changes across different types of human-modified and wild environments, 2) their seasonal fluctuations, and 3) the influence of climatic factors (relative humidity, temperature, and precipitations) on the temporal dynamics of these communities. In each habitat, five sites were selected for the collection of blow flies using bait traps, and flies were collected for 1 yr. In total, 32,100 blow flies were collected, distributed in five genera and 11 species. The native species Cochliomyia macellaria (Fabricius) (Diptera: Calliphoridae) was the most abundant, followed by the exotic Chrysomya putoria (Wiedemann) (Diptera: Calliphoridae). The abundance of exotic species represented 59.9% of the total sample, showing a reduction toward less disturbed sites. The Calliphorid communities were compared in terms of species richness, composition, and abundance between habitats and seasons. Our results showed that the habitat type and season affect the composition of blow fly communities. The alfalfa crop and the forest showed the highest diversity of species. In general, there was a decrease in blow fly activity during winter in all habitats. The climatic factors did not greatly affect the diversity of these flies. This study provides a first understanding of several ecological aspects of the Calliphoridae assemblages of the previously unsurveyed Humid Chaco ecoregion of South America.

Diversity and seasonal dynamics of an assemblage of sarcophagid Diptera in a gradient of urbanization.

Sarcophagid species inhabiting different locations in a rural-urban gradient were surveyed in the east central Argentine district of the Almirante Brown, Buenos Aires province. The main objectives of this research were to identify the most prevalent sarcophagid species and to describe community richness and diversity according to the degree of urbanization and the environmental variables measured in three locations within a rural-urban gradient sampled during two years from May 2005 to April 2007. Spatial and seasonal variations were the main factors involved in structuring the sarcophagid communities. Diversity was lower in urbanized areas than in rural ones. Bait and microhabitat preferences (sunny or shady places) and seasonal fluctuations were described for 17 sarcophagid species.

The population ecology of Muscina stabulans (Fallén) (Diptera: Muscidae), along an urban-rural gradient of Buenos Aires, Argentina.

The false stable fly, Muscina stabulans (Fallén), was surveyed along an urban-rural gradient at Almirante Brown, Buenos Aires province, Argentina. Samples were taken at monthly intervals from May 2005 to April 2007. Hourly captures of adult flies (10:00 am-04:00 pm) were taken at each sampling date with a hand net. The baits used were 250 g of rotten cow liver and 250 g of fresh dog faeces exposed in shaded and sunny areas. The entire sample accumulated 358 specimens. The number of specimens captured during the second year was higher than in the fi rst year. Muscina stabulans was more abundant at urban-suburban sites. Females showed significant preferences for cow liver. We caught more specimens in shaded areas. The hourly activity increased toward the afternoon at the three sites. The present work was the first ecological study related to a muscid species in Argentina.

The population ecology of Muscina stabulans (Fallén) (Diptera: Muscidae), along an Urban-Rural Gradient of Buenos Aires, Argentina

The false stable fly, Muscina stabulans (Fallén), was surveyed along an urban-rural gradient at Almirante Brown, Buenos Aires province, Argentina. Samples were taken at monthly intervals from May 2005 to April 2007. Hourly captures of adult flies (10:00 am - 04:00 pm) were taken at each sampling date with a hand net. The baits used were 250 g of rotten cow liver and 250 g of fresh dog faeces exposed in shaded and sunny areas. The entire sample accumulated 358 specimens. The number of specimens captured during the second year was higher than in the fi rst year. Muscina stabulans was more abundant at urban-suburban sites. Females showed significant preferences for cow liver. We caught more specimens in shaded areas. The hourly activity increased toward the afternoon at the three sites. The present work was the first ecological study related to a muscid species in Argentina.

New species and new records of Microcerella Macquart (Diptera: Sarcophagidae) belonging to the M. spinigena species-group.

A new species of the genus Microcerella Macquart, Microcerella cristiani sp. nov., is described from material obtained from Argentinean Patagonia. First records are given for Microcerella austrohartigia Pape in Argentina. Both species belong to the M. spinigena species group.

New species and new records of Microcerella Macquart (Diptera: Sarcophagidae) belonging to the M. spinigena species-group / Nueva especie y nuevos registros de Microcerella Macquart (Diptera: Sarcophagidae) pertenecientes al grupo M. spinigena

A new species of the genus Microcerella Macquart, Microcerella cristiani sp. nov., is described from material obtained from Argentinean Patagonia. First records are given for Microcerella austrohartigia Pape in Argentina. Both species belong to the M. spinigena species group.

Una nueva especie del género Microcerella Macquart, Microcerella cristiani sp. nov., es descripta a partir de material colectado en la Patagonia argentina. Se registra po primera vez para la Argentina a Microcerella austrohartigia Pape. Ambas especies pertenecen al grupo de especies M. spinigena.

Flesh flies species (Diptera: Sarcophagidae) from a grassland and a woodland in a Nature Reserve of Buenos Aires, Argentina

Temporal changes of flesh flies abundance were simultaneously recorded at monthly intervals during a year in a woodland and in a grassland at the "Reserva Ecológica Costanera Sur" (RECS), Buenos Aires city, Argentina. Samples were taken at monthly intervals (February 2004-January 2005). Hourly captures of adult flies (10:00 am - 04:00 pm) were taken each sampling date with a hand net. Temperature was recorded at each hourly capture. The baits used were 200 g of rotten cow liver and 200 g of fresh dog faeces. Records of abundance included only species whose abundance was ≥30 individuals accumulated during the whole sampling period. Considering overall abundance, a non-parametric Chi-square test was used to estimate deviations of an expected habitat and bait preference ratios of 1:1. The same criterion was applied to include species in a contingency table to describe their seasonality. The final matrix included four species whose associations to seasons were analyzed by using a Correspondence Analysis. To normalize the data, a log 10(n+1) transformation was applied prior to the analysis of correlation. Pearson product-moment correlations were used to examine the relationship between flesh-fly abundance with temperature and habitat preference. The entire sample accumulated 1 305 individuals and 18 species. The flies were more abundant in the grassland than in the woodland. Microcerella muehni, Oxysarcodexia paulistanensis, O. varia and Tricharaea (Sarcophagula) occidua exhibited the higher relative abundance, representing the remaining species less than 8 % of the entire sample. Most of the recorded species showed preference for faces as bait. Concerning the dominant species, all of them but M. muehni, a suggestively termophobic species, prevailed in late spring-summer. The observed species arrangement at both sites indicates low species diversity and equitability and high information per individual in the average. The referred community traits would indicate the possible effects of environmental disturbance due to the proximity of study sites to dense urban settlements. Rev. Biol. Trop. 56 (3): 1287-1294. Epub 2008 September 30.

Variaciones numéricas de especies de Sarcophagidae (Diptera) se registraron durante un año a intervalos mensuales (febrero 2004-enero 2005), en un pastizal y un bosque de la "Reserva Ecológica Costanera Sur" (RECS) de la ciudad de Buenos Aires. Se realizaron capturas horarias (10:00 am - 04:00 pm) en cada fecha de muestreo. La muestra de todo el año acumuló 1 305 individuos y 18 especies. Estos dípteros fueron más abundantes en el pastizal que en el bosque. Las especies más numerosas fueron: Microcerella muehni, Oxysarcodexia paulistanensis,O. varia y Tricharaea (Sarcophagula) occidua, en tanto que las restantes representaron menos de 8 % del total. La mayoría de las especies mostraron preferencia por las heces como cebo. Las especies dominantes, con excepción de la especie termofóbica M. muehni, prevalecieron en la primavera tardía y en el verano. La alta dominancia específica observada podría ser indicativa del desorden ecológico provocado por la influencia de asentamientos urbanos adyacentes a los sitios de muestreo.

Flesh flies species (Diptera: Sarcophagidae) from a grassland and a woodland in a Nature Reserve of Buenos Aires, Argentina.

Temporal changes of flesh flies abundance were simultaneously recorded at monthly intervals during a year in a woodland and in a grassland at the "Reserva Ecológica Costanera Sur" (RECS), Buenos Aires city, Argentina. Samples were taken at monthly intervals (February 2004-January 2005). Hourly captures of adult flies (10:00 am - 04:00 pm) were taken each sampling date with a hand net. Temperature was recorded at each hourly capture. The baits used were 200 g of rotten cow liver and 200 g of fresh dog faeces. Records of abundance included only species whose abundance was > or = 30 individuals accumulated during the whole sampling period. Considering overall abundance, a non-parametric Chi-square test was used to estimate deviations of an expected habitat and bait preference ratios of 1:1. The same criterion was applied to include species in a contingency table to describe their seasonality. The final matrix included four species whose associations to seasons were analyzed by using a Correspondence Analysis. To normalize the data, a log 10 (n+1) transformation was applied prior to the analysis of correlation. Pearson product-moment correlations were used to examine the relationship between flesh-fly abundance with temperature and habitat preference. The entire sample accumulated 1 305 individuals and 18 species. The flies were more abundant in the grassland than in the woodland. Microcerella muehni, Oxysarcodexia paulistanensis, O. varia and Tricharaea (Sarcophagula) occidua exhibited the higher relative abundance, representing the remaining species less than 8% of the entire sample. Most of the recorded species showed preference for faces as bait. Concerning the dominant species, all of them but M. muehni, a suggestively termophobic species, prevailed in late spring-summer. The observed species arrangement at both sites indicates low species diversity and equitability and high information per individual in the average. The referred community traits would indicate the possible effects of environmental disturbance due to the proximity of study sites to dense urban settlements.

Winter survival of immature instars of Mansonia indubitans Dyar & Shannon and Mansonia titillans Walker (Diptera: Culicidae), in Buenos Aires, Argentina.

We conducted a whole year research on the ecology of Mansonia indubitans and Ma. titillans in Macáes Pond, Costanera Sur Reserve, Buenos Aires, Argentina. The usage of different floating plants by immature instars and their overwintering was analyzed. The percentage of usage of the available floating macrophytes (Pistia, Limnobium, and Salvinia) by the larvae and pupae was studied. Also, we defined positivity (P+) as the percentage of plants with immature instars for each plant genus on a monthly basis. Ma. immature instars were captured throughout the year and Pistia was the resource most commonly exploited by the mosquitoes. The percentage of fourth-instar larvae and pupae on Pistia roots with respect to total immature instars captured was assessed on a monthly and seasonal basis. The proportion of fourth-instar larvae and pupae from both species of Mansonia on water lettuce roots, showed significant differences between months and seasons. Our results suggest that the populations of Ma. indubitans and Ma. titillans in Macáes Pond, survive during winter mainly as fourth-instar larvae.

Winter survival of immature instars of Mansonia indubitans Dyar & Shannon and Mansonia titillans Walker (Diptera: Culicidae), in Buenos Aires, Argentina

We conducted a whole year research on the ecology of Mansonia indubitans and Ma. titillans in Macáes Pond, Costanera Sur Reserve, Buenos Aires, Argentina. The usage of different floating plants by immature instars and their overwintering was analized. The percentage of usage of the available floating macrophytes (Pistia, Limnobium, and Salvinia) by the larvae and pupae was studied. Also, we defined positivity (P+) as the percentage of plants with immature instars for each plant genus on a monthly basis. Ma. immature instars were captured throughout the year and Pistia was the resource most commonly exploited by the mosquitoes. The percentage of fourth-instar larvae and pupae on Pistia roots with respect to total immature instars captured was assessed on a monthly and seasonal basis. The proportion of fourth-instar larvae and pupae from both species of Mansonia on water lettuce roots, showed significant differences between months and seasons. Our results suggest that the populations of Ma. indubitans and Ma. titillans in Macáes Pond, survive during winter mainly as fourth-instar larvae.

Host plant selection of two Mansonia blanchard species (Diptera: Culicidae) in a heterogeneous habitat of Buenos Aires City, Argentina.

Larvae and pupae of the genus Mansonia Blanchard attach to the roots of aquatic plants by means of modified structures to obtain oxygen. A study of the association of larval Ma. indubitans and Ma. titillans with floating macrophytes was conducted at Macies Pond, Argentina. Fifty-four sampling units were taken from January to May 2003. Three genera of host plants were considered: Pistia, Limnobium, and Salvinia. A total of 402 immatures of Ma. indubitans and 217 of Ma. titillans were captured and associations between Mansonia immatures and roots of each genera were assesed. Significant association was noted between Ma. indubitans and certain host plant species (K-W H=42.74, df=2, p<0.001). The same result was observed for Ma. titillans (K-W H=23.42, df=2, p<0.001). Both Mansonia species utilized roots of P. stratiotes in significantly higher proportions than expected by random selection. Both species showed significant negative association with Salvinia spp., while no clear relationships were detected with L. laevigatum.