Diversity of mites (Acari) in vineyard agroecosystems (Vitis vinifera) in two viticultural regions of Rio Grande do Sul state, Brazil

International audienceThe aim of this work was to study mite diversity in vineyard plots planted with Cabernet Sauvignon and Pinot Noir cultivars and on associated non-cultivated plants in two viticultural regions of Rio Grande do Sul State, Brazil. Monthly assessments of leaves and buds of vines and of non-cultivated plants were undertaken between October 2006 and September 2007. Twelve thousand mites belonging to 17 families and 46 genera and representing 61 mite species were collected. The most abundant phytophagous mites were Calepitrimerus vitis, Colomerus vitis and Panonychus ulmi on grapevines. Among the predatory mites, the most abundant were Neoseiulus californicus and Agistemus floridanus. The non-cultivated plants species that showed the greatest richness of mites were Plantago tomentosa, Plantago lanceolata and Senecio sp. The most abundant phytophagous mites on non-cultivated plants were Tetranychus ludeni and Brevipalpus phoenicis in the viticultural regions of Bento Gonçalves and Candiota, respectively, and Pronematus anconai was generally the most abundant predatory mite. In the region of Bento Gonçalves, species richness and abundance in the agroecosystem were far higher than in the region of Candiota

Distribuição espacial e plano de amostragem de Calacarus heveae (Acari) em seringueira

Calacarus heveae Feres, 1992 (Eriophyidae) is a mite described from specimens collected on rubber tree (Hevea brasiliensis, Euphorbiaceae) in the northwest region of the state of São Paulo. This mite prefers the adaxial face of the folioles which it can turn dry, yellowish and brownish; it can also cause leaf fall. The aim of this work was to analyze the distribution of C. heveae on rubber trees, to select the most representative sampling unit and to develop a sampling plan to determine the populational fluctuation. This study was conducted with clones PB 260 and IAN 873, in Itiquira and Pontes e Lacerda, respectively, both in the state of Mato Grosso. In Itiquira, significant differences were observed in four occasions in relation to the average number of mites per leaf in the different plant strata. In the samplings carried out in Pontes e Lacerda, no significant differences were observed between strata in relation to that parameter. Only in Itiquira, in one occasion, a significant difference between strata was verified in relation to the proportion of infested leaves. No significant differences were verified in relation to the average number of mites per leaf and proportion of leaves infested by C. heveae at different depths in the canopy. Calacarus heveae exhibits aggregated distribution in the field. To estimate the density of C. heveae, numeric and sampling plans were developed

Seletividade de acaricidas e inseticidas a ácaros predadores (Acari: Phytoseiidae) encontrados em seringueira no centro-oeste do Brasil Side-effect of acaricides and insecticides to predatory mites (Acari: Phytoseiidae) found in rubber-trees in mid-west Brazil

Euseius concordis (Chant) e Neoseiulus anonymus (Chant & Baker) são ácaros predadores da família Phytoseiidae comumente encontrados em seringueira (Hevea brasiliensis Muell. Arg.) em Mato Grosso, região centro-oeste do Brasil. Este trabalho foi realizado para verificar o efeito de acaricidas e inseticidas-acaricidas empregados em plantações de seringueira, e outros que teriam potencial para serem empregados contra insetos e ácaros considerados pragas dessa cultura, sobre E. concordis e N. anonymus. Utilizou-se o método residual de pulverização em superfície, recomendado como padrão pelo Grupo de Trabalho "Pesticidas e Artrópodes Benéficos", da Organização Internacional de Controle Biológico e Integrado de Plantas e Animais Nocivos/Seção Regional do Paleártico Oeste. Duas concentrações de cada um dos seguintes ingredientes ativos foram utilizadas: acefato, dicofol, endosulfan, formetanate, metomil, monocrotofós, óxido de fenbutatin e propargite. Uma das concentrações utilizadas foi uma média daquelas sugeridas pelos fabricantes para o controle de ácaros e insetos fitófagos presentes em outras culturas, uma vez que nenhum dos produtos testados tem registro para o uso em seringueira e a outra correspondeu à cerca de um terço da primeira. Endosulfan a 320ppm, dicofol a 100ppm e óxido de fenbutatin a 100 e 320ppm foram inócuos a E. concordis, enquanto que endosulfan a 320ppm e dicofol a 100ppm foram inócuos a N. anonymus. Acefato, formetanate e monocrotofós, nas concentrações testadas, foram nocivos às duas espécies.<br>Euseius concordis (Chant) and Neoseiulus anonymus (Chant & Baker) are predatory mites of the family Phytoseiidae commonly found on rubber trees (Hevea brasiliensis Muell. Arg.) in the State of Mato Grosso, in the mid-west Brazil. This work was conducted to verify the effect of acaricides and insecticides-acaricides occasionally used in rubber tree plantations, and other products that could be used against different pests (insects and mites) in this crop, on E. concordis and N. anonymus. The residual contact spray method in glass surface was used, which is recommended by the Working Group on "Pesticides and Benefic Arthropods" of the International Organization of Biologic and Integrated Control of Noxious Plants and Animals/Regional Section of the West Paleartic (IOBC/WPRS). Two concentrations of the following active ingredients were used: acephato, dicofofol, endosulfan, formetanate, metomil, monocrotophos, oxid of fenbutanin and propargit. For each product, one of the concentrations used was an average of the concentrations recommended by the manufacturers for the control of mites and phytophagous insects in other crops, since none of the tested products are registered for use on rubber tree. The other concentration corresponded to ca. a third of the former concentration. Endosulfan at 320ppm, dicofol at 100ppm and fenbutanin oxid at 100 and 320ppm were harmless to E. concordis, while endosulfan at 320ppm and dicofol at 100ppm were harmless to N. anonymus. Acephate, formetanate and monocrotofós, in concentrations, were harmful to both species