RESUMO

Two new species, Xenotarsonemus quiriri n. sp. and Xenotarsonemus scorpius n. sp., are described and illustrated in this paper based on specimens collected on Myrtaceae plants in Atlantic Forest areas of the states of Bahia and Santa Catarina, Brazil. A key to identification of Xenotarsonemus species reported from Brazil is provided.

Assuntos

RESUMO

The mite community has been surveyed in Seasonal Semideciduous Forest with three types of surrounding agricultural environments to test the hypothesis that abundance and richness of mites in forest fragments are influenced by the type of agricultural environment. The survey has been carried out in six fragments, divided into sets of two fragments, each one neighboring one sort of agricultural environment: sugarcane crop (FS), orange crop (FO) and pasture (FP). In each fragment, ten individuals of Actinostemon communis (Euphorbiaceae) were selected, five at the edge and five within each fragment. Iphiseiodes zuluagai, often registered in orange crops, was more abundant in the fragments neighboring such crop, as well as some species of Tarsonemidae. In this study, the Phytoseiidae were more abundant in the fragments neighboring pasture, while sugarcane crops probably favored occurrence of phytophagous mites in the neighboring fragments. Tetranychidae were less abundant in FO, which can be explained by periodical use of pesticides in the orange crops. Forest fragments are important for colonies of predators in the neighboring crops, mainly for annual crops such as sugarcane, where the close perennial environment is very important for colonization of the crop. Maintenance of those areas, besides favoring preservation of wild species of mite, is very important to increase diversity of the neighboring agricultural ecosystems.

Assuntos

RESUMO

The mite community has been surveyed in Seasonal Semideciduous Forest with three types of surrounding agricultural environments to test the hypothesis that abundance and richness of mites in forest fragments are influenced by the type of agricultural environment. The survey has been carried out in six fragments, divided into sets of two fragments, each one neighboring one sort of agricultural environment: sugarcane crop (FS), orange crop (FO) and pasture (FP). In each fragment, ten individuals of Actinostemon communis (Euphorbiaceae) were selected, five at the edge and five within each fragment. Iphiseiodes zuluagai, often registered in orange crops, was more abundant in the fragments neighboring such crop, as well as some species of Tarsonemidae. In this study, the Phytoseiidae were more abundant in the fragments neighboring pasture, while sugarcane crops probably favored occurrence of phytophagous mites in the neighboring fragments. Tetranychidae were less abundant in FO, which can be explained by periodical use of pesticides in the orange crops. Forest fragments are important for colonies of predators in the neighboring crops, mainly for annual crops such as sugarcane, where the close perennial environment is very important for colonization of the crop. Maintenance of those areas, besides favoring preservation of wild species of mite, is very important to increase diversity of the neighboring agricultural ecosystems.(AU)

Foi estudada a comunidade de ácaros em fragmentos de mata estacional semidecidual com três tipos de ambientes agrícolas circunvizinhos para testar a hipótese de que a abundância e a riqueza de ácaros em fragmentos florestais são influenciadas pelo tipo de ambiente agrícola. O estudo foi conduzido em seis fragmentos, divididos em três conjuntos de dois fragmentos, sendo cada conjunto vizinho de um determinado tipo de ambiente agrícola: canavial (FS), laranjal (FO) e pastagem (FP). Em cada fragmento foram selecionados e marcados dez indivíduos de Actinostemon communis (Euphorbiaceae), cinco na borda e cinco no interior do fragmento. Iphiseiodes zuluagai, registrado frequentemente em laranjais, foi mais abundante nos fragmentos vizinhos a essa cultura, bem como algumas espécies de Tarsonemidae. Neste estudo os fitoseídeos foram mais abundantes nos fragmentos vizinhos de áreas de pastagens, enquanto os cultivos de cana-de-açúcar provavelmente favoreceram a ocorrência de fitófagos nos fragmentos adjacentes. Os tetraniquídeos foram menos abundantes em FO, o que pode ser explicado pela aplicação periódica de pesticidas nos laranjais. Fragmentos florestais são importantes para a colonização de predadores nas culturas vizinhas, principalmente em culturas anuais, como a cana-de-açúcar, nas quais o ambiente perene próximo é muito importante para a colonização do cultivo. A conservação dessas áreas, além de favorecer a manutenção de espécies silvestres de ácaros é de grande importância para o aumento da diversidade nos agroecossistemas vizinhos.(AU)

Assuntos

RESUMO

RESUMO Este trabalho teve por objetivo relatar pela primeira vez a ocorrência dos ácaros Amblyseiella setosa Muma (Phytoseiidae) e Tuckerella pavoniformis (Ewing) (Tuckerellidae) no Brasil. Os ácaros foram coletados em folhas de lichieira, oriundos dos Municípios de Atibaia e Campinas, Estado de São Paulo, Brasil.

ABSTRACT The article reports for the first time the occurrence of mites Amblyseiella setosa Muma (Phytoseiidae) and Tuckerella pavoniformis (Ewing) (Tuckerellidae) in Brazil. The specimens were collected in litchi leaves from Atibaia and Campinas, the counties of state of São Paulo, Brazil.

RESUMO

RESUMO Visando avaliar o potencial de predação dos ácaros Amblyseius acalyphus Denmark & Muma e Amblyseius neochiapensis Lofego, Moraes & McMurtry como predadores de 2 ácaros fitófagos encontrados em goiabeira, Brevipalpus phoenicis (Geijskes) e Oligonychus psidii Flechtmann, conduziu-se o presente estudo para avaliar os níveis de oviposição daqueles predadores quando alimentados com aqueles ácaros, assim como, para comparação, quando alimentados com Tetranychus urticae Kock e pólen de Typha angustifolia L. Os testes foram realizados em unidades experimentais preparadas com folhas de Psidium guajava L. no caso de A. neochiapensis e folhas de P. guajava e Citrus sinensis (L.) Osbeck no caso de A. acalyphus. Nos testes sobre folhas de P. guajava, as oviposições médias obtidas para A. acalyphus foram sempre menores que 0,7 ovo por fêmea por dia. Para A. neochiapensis foi obtida a média diária de 1,1 ovo por fêmea alimentada com pólen e 0,7 ovo por fêmea alimentada com B. phoenicis, T. urticae ou O. psidii. Mesmo quando utilizando folhas de C. sinensis, a oviposição de A. acalyphus foi baixa, atingindo no máximo 0,8 ovo por fêmea por dia, quando as fêmeas foram alimentadas com uma combinação pólen + B. phoenicis.

ABSTRACT Aiming to evaluate the pontential of predation of the mites Amblyseius acalyphus Denmark & Muma and Amblyseius neochiapensis Lofego, Moraes & McMurtry as predators of 2 phytophagous mites found on guava trees, Brevipalpus phoenicis (Geijskes) and Oligonychus psidii Flechtmann, the present work was conducted to evaluate the oviposition levels of those predators when they feed on those mites, and compare these to the oviposition levels when they feed on Tetranychus urticae Kock and pollen of Typha angustifolia L. The experiments were done in experimental units made with leaves of Psidium guajava L. in the case of A. neochiapensis, and leaves of P. guajava and Citrus sinensis (L.) Osbeck in the case of A. acalyphus. For the experiments done on leaves of P. guajava the average ovipositions obtained for A. acalyphus were always smaller than 0.7 egg per female per day. For A. neochiapensis the average was 1.1 egg per female that fed on pollen and 0.7 egg per female that fed on B. phoenicis , T. urticae or O. psidii. Also, when C. sinensis leaves were used, the oviposition ofA. acalyphus was low, reaching the maximum of 0.8 egg per female per day, when the female fed on a combination of pollen + B. phoenicis.