Genetic Variation and Differentiation of Hylesia metabus (Lepidoptera: Saturniidae): Moths of Public Health Importance in French Guiana and in Venezuela.

Hylesia moths impact human health in South America, inducing epidemic outbreaks of lepidopterism, a puriginous dermatitis caused by the urticating properties of females' abdominal setae. The classification of the Hylesia genus is complex, owing to its high diversity in Amazonia, high intraspecific morphological variance, and lack of interspecific diagnostic traits which may hide cryptic species. Outbreaks of Hylesia metabus have been considered responsible for the intense outbreaks of lepidopterism in Venezuela and French Guiana since the C20, however, little is known about genetic variability throughout the species range, which is instrumental for establishing control strategies on H. metabus. Seven microsatellites and mitochondrial gene markers were analyzed from Hylesia moths collected from two major lepidopterism outbreak South American regions. The mitochondrial gene sequences contained significant genetic variation, revealing a single, widespread, polymorphic species with distinct clusters, possibly corresponding to populations evolving in isolation. The microsatellite markers validated the mitochondrial results, and suggest the presence of three populations: one in Venezuela, and two in French Guiana. All moths sampled during outbreak events in French Guiana were assigned to a single coastal population. The causes and implications of this finding require further research.

Protein content of the Hylesia metabus egg nest setae (Cramer [1775]) (Lepidoptera: Saturniidae) and its association with the parental investment for the reproductive success and lepidopterism.

Hylesia metabus is a neotropical moth possessing toxic setae, which once in contact with the skin cause a severe dermatitis to humans known as lepidopterism. The only known function of the setae in the life cycle is to provide protection during the mating and egg-hatching stages. Approximately 65% of the protein content of the setae is a cluster of five proteases (28-45kDa) showing sequence homology to other S1A serine proteases. The N-glycans of a 40kDa protease are a mixture of neutral and sulfated G0F structures. The sulfated N-glycans have an important role in triggering the inflammatory response typical of lepidopterism while the proteolytic activity may promote the erosion of blood vessels and tissues causing focal hemorrhages. The presence of Chitinase and a 30kDa lipoprotein is probably related to the antifungal defense. In addition, chitin digestion of the setae may potentiate the inflammatory reaction caused by the toxins due to the formation of chitin adjuvants fragments. The combined effect of proteases and a chitinase may dissuade predating arthropods, by damaging their exoskeletons. Vitellogenin, a bacteriostatic protein, is able to recognize pathogen-associated patterns, which suggests its possible role in protecting the embryonated eggs from pathogenic microorganisms. SIGNIFICANCE: The present study is the first report describing the different protein species present in the urticating egg nest setae of the neotropical moth Hylesia metabus - the most harmful of the Hylesia moths - causing a severe urticating dermatitis in humans known as lepidopterism. A distinctive feature of the venom is the presence of five different S1A serine proteases probably used to guarantee a more efficient degradation of a wider number of protein substrates. This work confirms that the presence of sulfated N-glycans is not an isolated finding since its presence has been demonstrated in two different proteases affirming that this PTM is of importance for the activation of the inflammatory response typical of lepidopterism. Additionally, this study gives useful information on the defense mechanisms used for protection of its progeny vs. vertebrate predators, fungus, bacteria or other arthropods such as ants. The proteins detected in the egg nest should be seen as an extended parental effort made by the females in order to achieve an optimal reproductive success, thus compensating for the considerable loss of progeny during the larval stages that seriously limits the number of sexually mature adults reaching the reproductive phase.

Pruebas de campo sobre la eficacia y persistencia de tres formulaciones de Bacillus sphaericus contra larvas de Anopheles aquasalis Curry en manglares del municipio Mariño, estado Sucre, Venezuela / Field trials on the efficacy and persistence of three formulations of Bacillus sphaericus against larvae of Anopheles aquasalis Curry in mangroves of Mariño municipality, Sucre state, Venezuela

Anopheles aquasalis Curry es el principal vector de malaria de la región nororiental de Venezuela. Un estudio sobre el control biológico de la especie fue realizado en Rio Chiquito Abajo, municipio Mariño, estado Sucre. El objetivo del mismo fue evaluar en condiciones de campo, la eficacia y persistencia de tres formulaciones comerciales de Bacillus sphaericus contra larvas de An. aquasalis. Los criaderos típicos de esta especie son humedales de agua dulce con vegetación herbácea emergente y manglares salobres estacionales con vegetación arbórea (Avicennia germinans). El hábitat seleccionado para realizar los bioensayos fue un típico manglar de Avicennia germinans. En este criadero de An. aquasalis, se evaluaron estas formulaciones de B. sphaericus: dos formulaciones liquidas (GRISELESF-Cepa 2362 y VECTOLEX® WGD-51,2%) y una formulación granulada (VECTOLEX® CG-7,5%). En cada prueba, se aplicó un diseño completamente al azar con 4 repeticiones por tratamiento y por control. Los resultados fueron expresados como porcentajes de reducción larval, después de aplicar la formula de Mulla. De acuerdo con los resultados obtenidos, la formulación granulada VECTOLEX® CG-7,5% con dosis de 30 Kg/ha (3 g/m²), resultó ser altamente eficaz hasta 7 días post-aplicación con 92,3% de reducción, la misma fue menos efectiva después de 14 días post-aplicación con 74,8%. Al aumentar la dosis a 40 Kg/ha (4 g/m²), la eficacia después de 7 días de la aplicación fue de 93,9 %, es decir muy similar que a la dosis anterior. Ambas dosis presentaron la misma eficacia contra larvas de An. aquasalis. Por otra parte, la otra formulación VECTOLEX® WGD-51,2%, con la dosis de 2,0 Kg/ ha, resultó ser eficaz hasta 8 días post-aplicación con 85,2% de reducción larval; la misma produjo 13,3% de reducción a los 16 días post-tratamiento; sin embargo, esta formulación con la dosis de 2,5 Kg/ha, fue altamente eficaz hasta 16 días postaplicación con más de 90% de reducción larval. En cambio, en el mismo manglar el producto GRISELESF fue menos eficaz tanto a 2,0 Kg/ha como a 2,5 Kg/ha, obteniéndose porcentajes de reducción muy bajos a los 8 y 16 días post-aplicación.

Anopheles aquasalis Curry is the main vector of malaria in northeastern Venezuela. A study of biological control of An. aquasalis larvae was carried out in Río Chiquito Abajo, Sucre State, Venezuela. The objective of this study was to evaluate effectivity and persistence of three formulations of Bacillus sphaericus against larval populations of An. aquasalis. The main breeding-sites of An. aquasalis are seasonal brackish mangrove with Avicennia germinans and semi-permanent freshwater wetlands with herbaceous emergent vegetation. A typical seasonal brackish mangrove with Avicennia germinans was selected. In these breeding-sites of An. aquasalis, three commercial formulations of B. sphaericus: VECTOLEX® CG-7.5%, VECTOLEX® WGD-51.2% and GRISELESF were evaluated in field trials. According to the results obtained VECTOLEX® CG-7.5% was effective against An. aquasalis larvae during 7 days post-treatment at rates not lower than 30 Kg/ha (3 g/m²), producing a larval reduction greater than 92.3%. This granular formulation provided very good larval control during 7 days. The two dosages (30 and 40 Kg/ha) had the same efficacy against An. aquasalis larvae. The second commercial formulation VECTOLEX® WGD-51.2% was effective against An. aquasalis larvae at dose of 2.0 Kg/ ha, producing a larval reduction greater than 85 % during 8 days post-treatment, and only 13.3 % larval reduction at 16 days after treatment; but the same formulation with at dose of 2.5 Kg/ha was more effective, producing a larval reduction greater than 90 % during 16 days posttreatment. In the same brackish mangrove, GRISELESF at rates not lower than 2.0 and 2.5 Kg/ha, appears to be less effective against An. aquasalis larvae, producing very low larval reduction at 8 and 16 days post-treatment.

Comparison of two commercial formulations of Bacillus thuringiensis var. israelensis for the control of Anopheles aquasalis (Diptera: Culicidae) at three salt concentrations.

Anopheles aquasalis larvae are salt water tolerant, preferring concentrations between 10 and 20 parts per thousand (ppt). The larvicidal efficacy of two formulations of Bacillus thuringiensis var. israelensis (Vectobac-12AS and Bactivec), was investigated against An. aquasalis at salinities of 0, 10, and 20 ppt. A probit analysis was used to calculate the lethal concentrations (LC50 and LC95) for each product at each salinity. The LC50 and LC95 were higher for Bactivec than Vectobac-12AS, and for Bactivec, the LC50 and LC95 increased with salinity. Vectobac-12AS should thus be preferred to Bactivec for An. aquasalis control, especially in saline breeding habitats.

Comparison of two commercial formulations of Bacillus thuringiensis var. israelensis for the control of Anopheles aquasalis (Diptera: Culicidae) at three salt concentrations

Extracts of propolis samples collected in Brazil and Bulgaria were assayed against four Leishmania species - Leishmania amazonensis, L. braziliensis, L. chagasi from the New World, and L. major from the Old World - associated to different clinical forms of leishmaniasis. The composition of the extracts has been previously characterized by high temperature high resolution gas chromatography coupled to mass spectrometry. Considering the chemical differences among the extracts and the behavior of the parasites, it was observed significant differences in the leishmanicidal activities with IC50/1 day values in the range of 2.8 to 229.3 µg/ml . An overall analysis showed that for all the species evaluated, Bulgarian extracts were more active than the ethanol Brazilian extract. As the assayed propolis extracts have their chemical composition determined it merits further investigation the effect of individual components or their combinations on each Leishmania species

Eficacia del Griselesf® (Bacillus sphaericus 2362) como controlador biológico de larvas de Anopheles aquasalis curry / The effectiveness of Griselesf® (Bacillus sphaericus 2362) as a biological control of larvae of Anopheles aquasalis curry

Actualmente existen diferentes productos a base de Bacillus spp. que tienen un efecto larvicida sobre Anopheles spp., vectores de la malaria. Sin embargo, su eficacia es variable dependiendo de la especie blanco y las condiciones ambientales. Se evaluó la efectividad del producto Griselesf® (Bacillus sphaericus 2362) como controlador biológico de Anopheles aquasalis, principal vector de malaria en el estado Sucre, en dos ocasiones bajo las mismas condiciones de laboratorio, en el año 2002 y luego en el 2006. Se prepararon soluciones del producto a concentraciones de 1, 5, 10, 50 y 100 ppm (año 2002) y 5, 25, 50, 75 y 100 ppm (año 2006), en 600 mL de agua potable. Luego se trasvasaron 100 mL de cada una de las soluciones en envases plásticos de 250 mL y se colocaron 10 larvas de los estadíos tercero tardío o cuarto temprano en cada uno de los recipientes. En el 2002, a los 48 horas en 100 ppm el Griselesf® había matado solamente 0,84% de la población aumentando a 25% a las 72 horas. En el 2006, en 100 ppm, hubo mortalidades de 6,67 y 11,67% de las poblaciones de las larvas a las 48 y 72 horas respectivamente. Los resultados sugieren que Griselesf® no es efectivo contra las larvas de An. aquasalis del estado Sucre.

Lepidopterism due to exposure to the moth Hylesia metabus in northeastern Venezuela.

Lepidopterism refers to a spectrum of medical conditions in humans that usually involves the skin and results from contact with the adult or larval forms of certain butterflies and moths. We analyzed the epidemiologic and clinical features associated with exposure to the moth Hylesia metabus between 1970 and 2002 in the Cajigal district, Sucre, Venezuela. Fifty cases of lepidopterism mostly affecting individuals under 18 years of age were identified during this period and manifested as pruritic dermatitis with or without associated respiratory symptoms. With increased travel to endemic areas of lepidopterism, travel and tropical medicine practitioners should be aware of the clinical spectrum of this condition.

Caracterización ecoregional de los vectores de malaria en Venezuela / Ecoregional characterization of the vectors of malaria in Venezuela

Se presenta la distribución fisiográfica de los vectores de malaria en Venezuela, basada en la revisión de trabajos publicados y consultas a especialistas a partir de los primeros registros disponibles desde 1910 hasta el presente. La información recopilada fue plasmada en mapas realizados con el programa Surfer (V. 8.01) y ubicados en las diferentes ecoregiones identificadas para Venezuela. El presente trabajo constituye un primer esfuerzo por crear una base de datos sobre la distribución de anofelinos vectores de malaria en Venezuela y ponerla a disposición del MSDS y la comunidad científica