Temporal Variation in Species Abundance and Richness of Culicoides (Diptera: Ceratopogonidae) in a Tropical Equatorial Area.

The aim of this study was to investigate whether temperature, rainfall, and humidity influence the annual distribution of Culicoides Latreille 1809, species abundance and richness in rural areas on São Luís Island in the state of Maranhão, Brazil. Biting midges were collected in housing for domestic animals in the peridomestic areas of 10 homes. A CDC light trap was installed in each peridomestic area from 6:00 p.m. to 6:00 a.m. once a month for 12 mo. In total, 23,633 individuals belonging to 26 Culicoides species were captured. The most abundant species were Culicoides diabolicus Hoffman, 1925 (27.43%), C. ignacioi Forattini, 1957 (25.9%), C. flavivenulus Costa Lima, 1937 (15.53%), C. insignis Lutz, 1913 (10.66%), C. filariferus Hoffman, 1939 (6.21%), C. boliviensis Spinelli & Wirth, 1984 (6.07%), C. foxi Ortíz, 1950 (2.83%), and C. leopoldoi Ortíz, 1951 (2.54%). Species richness and abundance were greater during the rainy season (24 species; 88% of the individuals) than during the dry season (18 species; 12% of individuals). However, persistent rain on the days the midges were collected or in the preceding 24 h adversely affected abundance. Mean monthly maximum temperature and rainfall on the day of the collection adversely affected Culicoides abundance and richness.

Ecology of phlebotomines (Diptera, Psychodidae) in rural foci of leishmaniasis in tropical Brazil.

INTRODUCTION: This work aimed to study the community structure of sandflies, with regard to the richness, constancy, abundance, and monthly frequency of the species with a focus on the transmission of leishmaniasis. METHODS: The study was conducted in the rural villages of Bom Jardim and Santa Maria, situated on the edge of a tropical rain forest in the municipality of São Jose de Ribamar, Maranhão, Brazil. The phlebotomines were captured in the intradomiciles and peridomiciles of each village, with Centers for Disease Control (CDC) light traps set in 10 homes in each village, for 1 year, once a month, from 18h to 6h. RESULTS: We collected 1,378 individuals of 16 sandfly species. The capture success rate was higher in Bom Jardim (0.61 specimens/hour/trap) than that of Santa Maria (0.35/specimens/hour/trap). The sandflies were more abundant in the peridomiciles (86.1%) and in the rainy season (77%). Five species were considered constants (occurring in more than 50% of samples), 5 accessory (25%-50%), and 6 accidental (<25%). The most abundant species were Lutzomyia longipalpis (59.7%) and L whitmani (28%). The permutation analysis showed differences between the species composition of the villages and no separation between the intradomicile and peridomicile of each village. The species that most contributed to the dissimilarity between the light traps of the 2 villages were L. longipalpis, L. whitmani, and L. evandroi, contributing to 80.8% of the variation among groups. CONCLUSIONS: The high level of richness and abundance of species and the presence of competent vectors throughout the year and around houses justify the occurrence of leishmaniasis cases reported in the area.

Formigas (Hymenoptera: Formicidae) como vetores de bactérias em ambiente hospitalar na cidade de São Luis - Maranhão / Ants (Hymenoptera: Formicidae) as vectors of bacteria in a hospital environment in São Luís-MA City

Dentro do ambiente hospitalar, as formigas têm exercido um importante papel no carreamento de microrganismos patogênicos. Os objetivos deste estudo foram detectar as bactérias carreadas por formigas coletadas em uma Unidade Mista da cidade de São Luís-MA, traçar o perfil desusceptibilidade aos antibióticos e identificar o gênero dos insetos. As coletas foram realizadas de agosto a outubro de 2010 em seis setores do local estudado por meio de busca ativa com auxílio de swabs. A identificação das Enterobactérias foi realizada com o uso de kit. O antibiograma seguiu o método de difusão em disco e a identificação das formigas ocorreu através do uso de chave. Foram calculados o coeficiente de similaridade e o índice de intensidade média. O teste de Kruskal-Wallis foi utilizado para avaliar os perfis de susceptibilidade das cepas aos antimicrobianos. Foram coletadas 36 formigas e isoladas 21 bactérias. Os coeficientes e índices mais expressivos corresponderam aos dos gêneros Camponotus spp. e Solenopsis spp. A sensibilidade aos antibióticosmostrou-se estatisticamente significante em relação aos demais perfis. O presente estudo contribuiupara melhor elucidar a situação do estado do Maranhão no painel da veiculação de microrganismospatogênicos por formigas em ambiente hospitalar.

Ecology of phlebotomines (Diptera, Psychodidae) in rural foci of leishmaniasis in tropical Brazil / Ecologia de flebotomíneos (Diptera, Psychodidae) em foco rural de leishmaniose no Brasil tropical

INTRODUCTION: This work aimed to study the community structure of sandflies, with regard to the richness, constancy, abundance, and monthly frequency of the species with a focus on the transmission of leishmaniasis. METHODS: The study was conducted in the rural villages of Bom Jardim and Santa Maria, situated on the edge of a tropical rain forest in the municipality of São Jose de Ribamar, Maranhão, Brazil. The phlebotomines were captured in the intradomiciles and peridomiciles of each village, with Centers for Disease Control (CDC) light traps set in 10 homes in each village, for 1 year, once a month, from 18h to 6h. RESULTS: We collected 1,378 individuals of 16 sandfly species. The capture success rate was higher in Bom Jardim (0.61 specimens/hour/trap) than that of Santa Maria (0.35/specimens/hour/trap). The sandflies were more abundant in the peridomiciles (86.1%) and in the rainy season (77%). Five species were considered constants (occurring in more than 50% of samples), 5 accessory (25%-50%), and 6 accidental (<25%). The most abundant species were Lutzomyia longipalpis (59.7%) and L whitmani (28%). The permutation analysis showed differences between the species composition of the villages and no separation between the intradomicile and peridomicile of each village. The species that most contributed to the dissimilarity between the light traps of the 2 villages were L. longipalpis, L. whitmani, and L. evandroi, contributing to 80.8% of the variation among groups. CONCLUSIONS: The high level of richness and abundance of species and the presence of competent vectors throughout the year and around houses justify the occurrence of leishmaniasis cases reported in the area.

INTRODUÇÃO: Este trabalho teve como objetivo estudar a estrutura da comunidade de flebotomíneos, dando a conhecer a riqueza, constância, abundância e a frequência mensal das espécies em foco de transmissão de leishmaniose. MÉTODOS: O estudo foi realizado nas localidades rurais de Bom Jardim e Santa Maria, situadas às margens de uma mata ombrófila infestada por esses insetos, no município de São José de Ribamar, Maranhão, Brasil. Os flebotomíneos foram capturados no intra e peridomicílio de cada vila, com 10 armadilhas luminosas tipo CDC em cada vila, durante um ano, uma vez por mês, das 18h às 6h. RESULTADOS: Foram capturados 1.378 indivíduos de dezesseis espécies e o esforço de captura foi maior em Bom Jardim (0,61 indivíduos/hora/armadilha) que em Santa Maria (0,35). Os flebotomíneos prevaleceram no peridomicílio (86,1%) e na estação chuvosa (77%). Cinco espécies foram consideradas constantes (ocorreram em mais de 50% das coletas), cinco acessórias (25% e 50%) e seis acidentais (< 25%). As espécies mais abundantes foram Lutzomyia longipalpis (59,7%) e Lutzomyia whitmani (28%). Estatisticamente, detectou-se uma diferença na composição das espécies entre os povoados. As espécies que mais contribuíram para a dissimilaridade entre as armadilhas das duas vilas foram Lutzomyia longipalpis, Lutzomyia whitmani e Lutzomyia evandroi, com 80,8% de variação entre os grupos. CONCLUSÕES: A elevada riqueza e abundância de flebotomíneos e a presença de vetores competentes ao longo do ano, justificam a ocorrência de casos de leishmanioses relatados na área.