When size and shape matter: morphometric characterization of two sympatric dragonflies of the genus Perithemis (Odonata: Libellulidae).

Perithemis mooma, Kirby, 1889 and Perithemis icteroptera (Selys in Sagra, 1857) live in sympatry from southern Brazil to central Argentina. The taxonomy of the genus Perithemis Hagen, 1861 has been hampered by the use of characters that are highly variable or show slight differences among species. Our objective was to assess the efficiency of traditional morphometrics (TM) and geometric morphometrics (GM) to discriminate between these species using wing size and shape and vulvar lamina contour, and to analyze the presence of sexual dimorphism in wing size and shape in both species. The TM and landmark-GM methods were applied on the fore and hind wings, while the outline-based GM method was applied on the vulvar lamina. GM allowed species delimitation using shape variables of either wing. The wing and vulvar lamina shapes were confirmed to be good diagnostic characters to separate these species and appear to be promising tools for distinguishing among other species of this genus. Centroid size failed to achieve species separation. Both species exhibited sexual size dimorphism (SSD). In contrast to what would be expected for Perithemis whose males are strongly territorial, P. icteroptera and P. mooma showed female-biased SSD suggesting a common pattern in Perithemis.

Review and redescription of species in the brasiliana group of Smicridea (Rhyacophylax) (Trichoptera, Hydropsychidae, Smicrideinae): exploration of the utility of geometric morphometrics as a method for delimitation and characterization of species in the genus.

The Smicrideabrasiliana species group includes five species distributed in northeastern Argentina and Brazil: Smicridea (Rhyacophylax) brasiliana (Ulmer), S. (R.) weidneri Flint, S. (R.) vermiculata Flint, S. (R.) arobasis Flint, and S. (R.) nanda Flint. The original descriptions of these species and their placement in the brasiliana species group were mainly based on the morphology of the male genitalia. However, the fine structure of the internal sclerites of the phallus, which proved to be useful for species delimitation, was not analyzed at the time. In this contribution, we provide a detailed description of the male genitalia and the morphology of the head, and analyze the shape of the wings using geometric morphometrics. The analyzed species can be easily differentiated by the shape of the phallus, especially by the structure of the internal sclerites, the shape of the head in dorsal view, and the shape of the cephalic setose warts. Furthermore, the geometric morphometric approach allowed their separation through the wing shape. The preliminary analysis of these features suggests that the brasiliana species group is not natural but its monophyly should be further tested within the framework of a phylogenetic analysis of all the species of the subgenus Rhyacophylax.

Status and forecast of leprosy in the still endemic province of Formosa in northern Argentina.

BACKGROUND: The province of Formosa, Argentina, is endemic for leprosy. In the present paper, we assessed the trend (T, 2002-2016 time series) and the forecast for 2022 of new case detection rate (NCDR) and determined the spatial distribution of new cases detected (NCD) of leprosy. METHODOLOGY/PRINCIPAL FINDINGS: This is a descriptive observational study of 713 NCD of leprosy from provincial medical records between January 2002 and December 2016. The whole dataset from the provincial medical record was used to independently estimate the NCDR trends of the general population, age groups, sexes and Departments. This same database was used to estimate the NCDR forecast of the general population for 2022, applying a dynamic linear model with a local linear trend, using the MCMC algorithm. The NCDR was higher in men (p<0.05), increased with age (0.20, 8.17, 21.04, and 29.49 for the 0-14, 15-44, 45-64 and over 65-year-old age groups, respectively; p<0.05) and showed a downward trend (negative values) of estimated slopes for the whole province and each Department. Bermejo Department showed the highest (T:-1.02, 95%CI: [-1.42, -0.66]) and Patiño the lowest decreasing trend (T:-0.45, 95%CI: [-0.74, -0.11]). The NCDR trend for both sexes was similar (T:-0.55, 95%CI: [-0.64, -0.46]), and age groups showed a decreasing trend (S15-44:-103, S45-64:-81, S>65:-61, p<0.05), except for the 0-14 age group (S:-3, p>0.05), which showed no trend. Forecasts predicted that leprosy will not be eliminated by 2022 (3.64, 95%CI: [1.22, 10.25]). CONCLUSIONS/SIGNIFICANCE: Our results highlight the status of leprosy in Formosa and provide information to the provincial public health authorities on high-risk populations, stressing the importance of timely detection of new cases for further elimination of the disease in the province.

Contribution to the knowledge of Lanta Hebard, 1921, with remarks on some male genital characters (Blattaria, Ectobiidae).

The genus Lanta Hebard 1921 includes three species found in the Neotropical region. Two species are known from Argentina, L. peniculiger (province of Santa Fe), and L. scotia (provinces of Córdoba and Santiago del Estero) (see Crespo et al. 2010), and one from Brazil, L. borgesae, (Araras, São Paulo) (Rocha e Silva & Vasconcellos, 1984). All species have been described on the basis of male external characters, such as wing veins, leg spines, hypandrium, shape and position of the styli, in addition to coloration and size. Except for a partial representation of the male genitalia of L. borgesae (Rocha e Silva & Vasconcellos 1984), this structure went untreated in morphological and phylogenetic investigations of the Blattaria (Snodgrass 1937; McKittrick 1964; Grandcolas 1996; Klass 1997; Roth 2003;). Females remain unknown.

Metabolism and water loss rate of the haematophagous insect Rhodnius prolixus: effect of starvation and temperature.

Haematophagous insects suffer big changes in water needs under different levels of starvation. Rhodnius prolixus is the most important haematophagous vector of Chagas disease in the north of South America and a model organism in insect physiology. Although there have been some studies on patterns of gas exchange and metabolic rates, there is little information regarding water loss in R. prolixus. We investigated whether there is any modulation of water loss and metabolic rate under different requirements for saving water. We measured simultaneously CO2 production, water emission and activity in individual insects in real time by open-flow respirometry at different temperatures (15, 25 and 35°C) and post-feeding days (0, 5, 13 and 29). We found: (1) a clear drop in metabolic rate between 5 and 13 days after feeding that cannot be explained by activity and (2) a decrease in water loss rate with increasing starvation level, by a decrease in cuticular water loss during the first 5 days after feeding and a drop in the respiratory component thereafter. We calculated the surface area of the insects and estimated cuticular permeability. In addition, we analysed the pattern of gas exchange; the change from a cyclic to a continuous pattern was affected by temperature and activity, but it was not affected by the level of starvation. Modulation of metabolic and water loss rates with temperature and starvation could help R. prolixus to be more flexible in tolerating different periods of starvation, which is adaptive in a changing environment with the uncertainty of finding a suitable host.

A new species of Chileotrecha Maury, 1987 (Solifugae: Ammotrechidae) from Argentina with notes on the genus.

The monotypic genus Chileotrecha Maury, 1987, includes Chileotrecha atacamensis Maury, 1987 from Atacama and Coquimbo regions in Chile. We describe Chileotrecha argentinensis n. sp., which is the first record of the genus from Argentina. Phylogenetic relationships of Chileotrecha with other genera of Ammotrechidae are discussed based on external morphology. We report for the first time the presence of blunt and clubbed setae in Ammotrechidae. We also report for the first time the presence of two pairs of microsetae in the posterior margin of genital plate and in the posterior margin of spiracular sternites I and II, and the presence of a single microseta on each side of postspiracular sternite I.

A longitudinal study of two species of Belostoma Latreille (Heteroptera: Belostomatidae): allometry and ontogeny / Estudio longitudinal en dos especies de Belostoma Latreille (Heteroptera: Belostomatidae): alometría y ontogenia

The multivariate allometric growth patterns from longitudinal data of leg and rostral segments of all instars of Belostoma elegans (Mayr) and B. cummingsi De Carlo are presented for the first time, and the allometric coefficients are compared. The segments of the middle and hind legs present allometric coefficients with opposite polarity to those of forelegs. This discrepancy in the ontogenetic trajectories may be due to the different functions of the legs. The foreleg main function is to capture of the prey, while the middle and hind legs are adapted to swimming. The relative size of rostral segments is an important taxonomic character in Belostoma. In B. cummingsi, the proximal segment is longer than the middle one, while in B. elegans they are subequal. Our purpose is to explain these differences through the analysis of their ontogenetic trajectories in an attempt to illuminate the morphological differences among species from a developmental perspective.

Los patrones de crecimiento alométrico de los segmentos del rostro y de las patas de Belostoma elegans (Mayr) y B. cummingsi De Carlo son presentados y comparados por primera vez. Se emplearon datos longitudinales de todos los estadios ninfales en un contexto multivariado. Los segmentos de la pata media y posterior presentan coeficientes alométricos con polaridad opuesta a los de la pata anterior. Estas diferencias observadas pueden deberse al diferente rol que presentan las patas. La función principal de la pata anterior es la captura de las presas, mientras que las patas media y posterior están adaptadas para la natación. El tamaño relativo de los segmentos del rostro es una característica taxonómica importante en Belostoma. En B.cummingsi el segmento proximal es más largo que el medio, mientras que en B. elegans son subiguales. Nuestro propósito es explicar estas diferencias a través del análisis de las trayectorias ontogéneticas en un intento de aclarar diferencias morfológicas entre especies desde una perspectiva del desarrrollo.

A longitudinal study of two species of Belostoma Latreille (Heteroptera: Belostomatidae): allometry and ontogeny.

The multivariate allometric growth patterns from longitudinal data of leg and rostral segments of all instars of Belostoma elegans (Mayr) and B. cummingsi De Carlo are presented for the first time, and the allometric coefficients are compared. The segments of the middle and hind legs present allometric coefficients with opposite polarity to those of forelegs. This discrepancy in the ontogenetic trajectories may be due to the different functions of the legs. The foreleg main function is to capture of the prey, while the middle and hind legs are adapted to swimming. The relative size of rostral segments is an important taxonomic character in Belostoma. In B. cummingsi, the proximal segment is longer than the middle one, while in B. elegans they are subequal. Our purpose is to explain these differences through the analysis of their ontogenetic trajectories in an attempt to illuminate the morphological differences among species from a developmental perspective.