Diversidade e flutuação populacional de ácaros (Acari) em Mabea fistulifera Mart. (Euphorbiaceae) de dois fragmentos de mata estacional semidecídua em São José do Rio Preto, SP
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Data
2005-04-01
Autores
Daud, Rodrigo D. [UNESP]
Feres, Reinaldo J.F. [UNESP]
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Título de Volume
Editor
Sociedade Entomológica do Brasil
Resumo
Amostrou-se mensalmente, durante 2001, ácaros de Mabea fistulifera Mart. em dois fragmentos de mata, um urbano e outro rural. em cada local e coleta, foram coletadas 20 folhas de cada um de três exemplares de M. fistulifera. As folhas foram examinadas sob estereomicroscópio e todos os ácaros encontrados, montados em lâminas e identificados e contados sob microscópio com contraste de fase. A diversidade e a uniformidade de espécies foram analisadas através dos índices de Shannon-Wiener e Pielou, respectivamente. O índice de similaridade de Morisita-Horn foi utilizado para determinar o grau de semelhança entre as áreas. A diversidade máxima teórica e a constância também foram determinadas. O índice de correlação de Pearson foi utilizado para verificar possíveis relações entre a abundância de ácaros com a pluviosidade. No fragmento urbano foram coletados 6326 ácaros pertencentes a 31 espécies, e no rural, 2330 ácaros de 25 espécies. Nos dois fragmentos, a diversidade excedeu 50% da diversidade máxima teórica, entretanto, no rural verificou-se maior diversidade. Registrou-se também, grande abundância de fitófagos, que foi maior no urbano, provavelmente como resultado do estresse das plantas favorecendo o desenvolvimento dos fitófagos. Alguns predadores apresentaram grande abundância durante a floração de M. fistulifera, provavelmente por utilizarem o pólen como alimento. A maior abundância de Euseius citrifolius Denmark & Muma, na estação seca, pode estar correlacionada com a maior disponibilidade de pólen, e não com a menor pluviosidade do período.
The mites on Mabea fistulifera Mart. in two forest fragments, urban and rural, were sampled monthly during 2001. For each site and each sampling date, 20 leaves were taken from each one of three trees. The leaves were inspected under dissecting microscope and all mites collected were mounted on slides, identified and counted by using a phase contrast microscope. Diversity and eveness were analyzed using the Shannon-Wiener and Pielou index, respectively. The Morisita-Horn index described similarities between the two sites. The Maximum Theoretical Diversity and Constancy index were also determined. Possible relationships between mite abundance and rainfall were investigated by Pearson correlation. The urban area had 6326 mites belonging to 31 species, while the rural area had 2330 individuals of 25 species. In both sites, the diversity exceeded 50% of the maximum theoretical diversity, but, the rural area showed higher diversity. Both sites had abundant phytophagous mites, however the abundance was higher in the urban fragment, as a result of plant stress that created more favorable conditions for phyphagous to develop. Some predaceous showed high abundance when the trees flowered. This occurs because some phytoseiids can use pollen as food. The only significant (negative) correlation was observed between rainfall and the population of Euseius citrifolius Denmark & Muma. However, the higher population of E. citrifolius on M. fistulifera in the dry season could be mostly due to the larger abundance of pollen in that period.
The mites on Mabea fistulifera Mart. in two forest fragments, urban and rural, were sampled monthly during 2001. For each site and each sampling date, 20 leaves were taken from each one of three trees. The leaves were inspected under dissecting microscope and all mites collected were mounted on slides, identified and counted by using a phase contrast microscope. Diversity and eveness were analyzed using the Shannon-Wiener and Pielou index, respectively. The Morisita-Horn index described similarities between the two sites. The Maximum Theoretical Diversity and Constancy index were also determined. Possible relationships between mite abundance and rainfall were investigated by Pearson correlation. The urban area had 6326 mites belonging to 31 species, while the rural area had 2330 individuals of 25 species. In both sites, the diversity exceeded 50% of the maximum theoretical diversity, but, the rural area showed higher diversity. Both sites had abundant phytophagous mites, however the abundance was higher in the urban fragment, as a result of plant stress that created more favorable conditions for phyphagous to develop. Some predaceous showed high abundance when the trees flowered. This occurs because some phytoseiids can use pollen as food. The only significant (negative) correlation was observed between rainfall and the population of Euseius citrifolius Denmark & Muma. However, the higher population of E. citrifolius on M. fistulifera in the dry season could be mostly due to the larger abundance of pollen in that period.
Descrição
Palavras-chave
Biological control, indigenous plant, Pest management, urban impact, Controle biológico, impacto urbano, manejo de pragas, Planta nativa
Como citar
Neotropical Entomology. Sociedade Entomológica do Brasil, v. 34, n. 2, p. 191-201, 2005.