ABSTRACT
Abstract Alocasia macrorrhizos (L.) G.Don grows and proliferates in shaded areas in several forest fragments in urban zones. The adult plant has axils that accumulate rain water (phytotelmata) and serve as breeding sites for several families of aquatic insects. The objective of this study was to determine the composition of the entomofauna associated with water accumulations in axils of A. macrorrhizos in urban areas of Manaus, Brazil. Individuals of A. macrorrhizos were sampled in five forest fragments, between April/2005 and March/2007 in urban areas of Manaus, totaling 184 sampling units. A manual suction hose was used for the removal of entomofauna. A total of 1,941 immatures of Diptera were collected representing the following families: Culicidae (96.5%), Chironomidae (2%), Psychodidae (0.7%), Ephydridae (0.7%) and Corethrellidae (0.1%). Five Culicidae species were identified: Wyeomyia melanocephala Dyar & Knab, 1906 (91.7%), Wy. ypsipola Dyar, 1922 (4.3%), Aedes albopictus (Skuse, 1894) (2.3%), Ae. aegypti (Linnaeus, 1762) (1.5%) and Johnbelkinia longipes (Fabricius, 1805) (0.1%). The members of Culicidae were the most abundant, confirming the importance of this group in communities associated with phytotelmata, with a positive relation to the volume of water (p < 0.05). The occurrence of Ae. aegypti and Ae. albopictus in axils of A. macrorrhizos demonstrates the potential of this Araceae as a breeding site of these medically important species. However, the real contribution of this Araceae in the maintenance and dispersion of populations of these two species of mosquitoes throughout the year should be further studied.
Resumo A. macrorrhizos (Araceae) é cultivada e se prolifera naturalmente em locais sombreados em diversos fragmentos de mata na zona urbana de Manaus. A planta adulta apresenta axilas que acumulam água da chuva (phytotelmata) e servem de criadouro para diversas famílias de insetos aquáticos. O objetivo do trabalho foi conhecer a composição da entomofauna associada às axilas de A. macrorrhizos, na área urbana de Manaus, Amazonas, Brasil. Entre 2005 e 2007, indivíduos de A. macrorrhizos foram amostrados em cinco fragmentos urbanos de mata, totalizando 184 unidades amostrais. Uma mangueira de sucção manual foi utilizada para coletar a fauna associada. Um total de 1.941 imaturos de Diptera foram coletadas, representadas pelas seguintes famílias: Culicidae (96,5%), Chironomidae (2%), Psychodidae (0,7%), Ephydridae (0,7%) e Corethrellidae (0,1%). Foram identificadas cinco espécies de Culicidae: Wyeomyia melanocephala Dyar & Knab, 1906 (91,7%), Wy. ypsipola Dyar, 1922 (4,3%), Aedes albopictus (Skuse, 1894) (2,3%), Ae. aegypti (Linnaeus, 1762) (1,5%) e Johnbelkinia longipes (Fabricius, 1805) (0,1%). Os representantes de Culicidae foram os mais abundantes confirmando a importância desse grupo nas comunidades associadas a fitotelmatas, com relação positiva com o volume de água por planta (p < 0.05). A ocorrência de Ae. aegypti e Ae. albopictus nas axilas de A. macrorrhizos demonstra o potencial dessa Araceae como criadouro para estas espécies de importância médica. Contudo, a real contribuição dessa Araceae na manutenção e dispersão populacional dessas duas espécies de mosquitos ao longo do ano precisa ser melhor estudada.
ABSTRACT
The aim of this work was to investigate the diversity of macroinvertebrates and also verify if the abundance and diversity of Diptera were influenced by the abiotic factors. The samples were collected from the epiphytic and terrestrial bromeliads G. brasiliensis (1 and 3m) in wet and dry seasons at Reserva Adolpho Ducke analyzed total of 144 samples were analyzed from a total of 15,238 individuals collected. These conatined 14,097 insects and, among these, 8,258 were immature Diptera, represented by eight most abundant families: Chironomidae, Ceratopogonidae and Culicidae. The relationship of Diptera diversity was influenced by the seasons and stratifications (p= 0.01); the abundance was influenced by the volume of water (p= 0.02) and the relationship between the season and volume of water in the terrestrial bromeliads was significant (p= 0.01). This study represented the first contribution to knowledge of community of macroinvertebrates associated to bromeliads G. brasiliensis in Central Amazon.
ABSTRACT
Mosquitoes in the family Culicidae develop their immature forms in different environments depending on various circumstances. This study represents the first contribution to the ecological knowledge of culicids living in the bromeliad G. brasiliensis. The objectives of the study were to compare the Culicidae fauna of bromeliads in two seasonal periods, analyzing their abundance, richness and the influence of pH, conductivity and water volume, on the populations. Sampling was done at Reserva Adolpho Ducke, Manaus, Amazonas, Brazil between 2003 and 2005. Six samplings were done in the rainy season and six in the dry season. On each sampling day, six terrestrial and six epiphytic bromeliads, totaling 144 sampling units, were retrieved. A total of 444 immature mosquitoes were collected, distributed in the following species: Culex (Microculex) stonei Lane & Whitman, Culex (Microculex) chryselatus Dyar & Knab, Culex (Microculex) sp., Wyeomyia (Hystatomyia) autocratica Dyar & Knab and Wyeomyia (Hystatomyia) splendida Bonne-Wepster & Bonne. The relationship between abundance of Culicidae and sampling period was not significant, although abundance was higher in the dry period. There were significant correlations between water volume and the abundance (p = 0.003) and richness (p = 0.001) of culicids. The pH was positively related to the occurrence of the species Wy. autocratica (p= 0.010) and Wy. splendida (p= 0.006), demonstrating the influence of this factor in the structuring of bromeliad-inhabiting communities.
Mosquitos da família Culicidae desenvolvem suas formas imaturas em vários ambientes na dependência de circunstâncias diversas. Este trabalho representa a primeira contribuição ao conhecimento ecológico de culicídeos em G. brasiliensis e tem como objetivo inventariar os imaturos em bromélias em dois períodos sazonais, analisando a abundância, riqueza e a influência das variáveis abióticas pH, condutividade e volume de água sobre as populações de Culicidae. Foram realizadas coletas na Reserva Adolpho Ducke, Manaus, Amazonas, Brasil entre 2003 e 2005. Seis coletas foram realizadas no período chuvoso e seis na estação seca. Em cada amostragem, seis bromélias terrestres e seis epífitas foram coletadas, totalizando 144 unidades amostrais. Um total de 444 imaturos foi coletado, distribuídos nas seguintes espécies: Culex (Microculex) stonei Lane & Whitman, Culex (Microculex) chryselatus Dyar & Knab, Culex (Microculex) sp., Wyeomyia (Hystatomyia) autocratica Dyar & Knab e Wyeomyia (Hystatomyia) splendida Bonne-Wepster & Bonne. A relação entre abundância de Culicidae e períodos não foi significativa, entretanto, o período seco apresentou maior representatividade de imaturos. Houve significância na relação do volume de água e abundância (p= 0,003) e riqueza (p= 0,001) de culicídeos. O pH foi o único parâmetro relacionado positivamente com a ocorrência das espécies Wy. autocratica (p= 0,010) e Wy. splendida (p= 0,006) ressaltando a influência deste fator na estruturação das comunidades bromelícolas.