Influência de fragmentos de cerrado na distribuição de ácaros em seringal

Abstract

-The aim of this study was to verify whether fragments of cerrado infl uence the composition of the mite fauna on rubber trees. Five transects distant 50 m, being the fi rst in the edge near the native areas and the last 200 m inside the crop, were established in each rubber tree crop in southern State of Mato Grosso. In each transect fi ve plants were chosen, and seven leaves were collected from each plant. During one year, 25 quantitative samplings were conducted in two rubber tree crops. The lowest number of phytophagous mites occurred in the transect closer to the native vegetation, and the highest number, in the most distant from the native vegetation. The largest diversity was also observed in the transect closer to the neighboring vegetation. Ten species of predatory mites were also registered in neighboring native areas. These data suggest the movement of predatory mites from the native areas to the monoculture. These natural areas can possibly supply alternative food and habitat for natural enemies of phytophagous mites in the period of food scarceness in the rubber tree crop. The presence of native areas close to culture areas should be taken into account in the elaboration of programs of ecological management of pests.KEY WORDS: Acari, agroecosystem, ecological pest management, Hevea brasiliensis, native area RESUMO -Este estudo teve como objetivo verifi car se fragmentos de cerrado infl uenciam na composição da acarofauna de seringais. Foram estabelecidos cinco transectos, distantes 50 m entre si, em duas áreas de cultivo no sul do Mato Grosso, sendo o primeiro na borda com o limite das áreas nativas e o último a 200 m no interior do seringal. Em cada transecto foram marcadas cinco plantas, sendo coletadas sete folhas de cada planta. Durante um ano foram realizadas 25 coletas quantitativas em dois cultivos de seringueiras. O menor número de fi tófagos foi registrado no transecto próximo da vegetação nativa e o maior no mais distante. A maior diversidade também foi observada no transecto mais próximo da vegetação nativa. Dez espécies de ácaros predadores também foram registradas nas áreas nativas vizinhas. Os dados sugerem o deslocamento dos ácaros predadores das áreas naturais para o monocultivo. Essas áreas naturais podem fornecer alimento alternativo e hábitat para inimigos naturais de fi tófagos no período de escassez de alimento no seringal. A presença de áreas nativas próximo a áreas de cultivo deve ser considerada na elaboração de programas de manejo ecológico de pragas. PALAVRAS-CHAVE: Acari, agroecossistema, manejo ecológico de pragas, Hevea brasiliensis, área nativa Fragmentos de mata nativa podem afetar a distribuição de ácaros em cultivos. Segundo Altieri (1994), as bordas são importantes para a propagação e proteção de ampla gama de agentes naturais de controle biológico de pragas agrícolas. Esses ambientes podem servir como corredores biológicos que permitem o movimento e distribuição de artrópodes benéfi cos. Estudos documentam a maior abundância de inimigos naturais e controle...

Mites (Arachnida, Acari) on Astronium fraxinifolium Schott (Anacardiaceae) from the Cerrado remnants associated with nickel mining areas

“…The mite genera recorded in this paper had been already sampled in Cerrado remnants from São Paulo, Goiás and Mato Grosso States by previous authors (Rezende et al 2014, Rezende and Lofego 2011, Demite et al 2009, Demite and Feres 2008, Lofego and Moraes 2006, Lofego et al 2005and Aranda 1974, except for genera Phytoscutus (Phytoseiidae) and Afronychus (Tetranychidae), which were recorded here for first time in Brazil Midwest Cerrado. Some of the genera sampled were also recorded in other Brazilian natural vegetations, such semi-deciduous forest remnants from São Paulo State, namely Agistemus, Brevipalpus, Euseius, Eotetranychus, Galendromus, Pronematus and Transeius (Demite et al 2013, Buosi et al 2006and Demite and Feres 2005.…”

“…Furthermore, important ecosystem services provided by natural vegetations to agriculture could have been reduced as a consequence of these modifications; mainly pollination (Yamamoto et al 2012) and natural pest control (Rezende et al 2014). Some investigations suggest Cerrado remnants as important shelters in keeping natural enemies of pests, such as predatory mites and parasitoid insects, and the benefit in conserving natural vegetation in crop-yielding areas for improving natural pest control (Demite and Feres 2008, 2007a, b, 2005, Demite et al 2009, Giannetti et al 2011, Harterreiten-Souza et al 2014, Rezende et al 2014.…”

“…So far, plant mites from Cerrado remnants were evaluated by Demite et al (2009), Demite & Feres (2008), Lofego & Moraes (2006), Lofego et al (2005) andFlechtmann (1967) at São Paulo and Mato Grosso States, Brazil. Rezende and Lofego (2011), in turn, sampled 26 phytoseiid species on 57 Cerrado native plant species from Midwest Brazil.…”

Influence of agricultural environment on the plant mite community in forest fragments

“…Therefore, strategies to reduce use of such products in the crop, or at least which avoid use in a portion of the crop close to the remnants should be taken into account in order to preserve the neighboring natural environment. Demite and Feres (2008) suggested that use of pesticides should be avoided in rubber-trees close to native areas, aiming to protect the fauna of predators which are found in there.…”

“…Demite and Feres (2007) also studied the relevance of native areas as reservoirs for Hirsutella thompsonii, an entomopathogenic fungus registered attacking the phytophagous mites more abundant in cultivation of rubber-tree crop in Mato Grosso State. However, no survey has been carried out to analyse influence of agricultural environments on mite community of neighboring forest remnants.…”