Periódicos
URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352
Navegar
4 resultados
Resultados da Pesquisa
Item Diversidade de ácaros (Arachnida: Acari) em Coffea arabica L. cv. Mundo Novo, nos municípios de Jeriquara e Garça, Estado de São Paulo(Instituto Virtual da Biodiversidade | BIOTA – FAPESP, 2006) Mineiro, Jeferson L. de C.; Sato, Mário E.; Raga, Adalton; Arthur, Valter; Moraes, Gilberto J. de; Sarreta, Fernando de O.; Carrijo, AlexO presente estudo teve como objetivo caracterizar a diversidade de ácaros em cafeeiros da cultivar Mundo Novo em duas importantes regiões produtoras (Jeriquara e Garça) do Estado de São Paulo. Para tanto, foram coletadas amostras quinzenais de folhas, ramos e frutos, entre abril de 2001 e junho de 2003, do terço médio de 10 plantas tomadas ao acaso em cada campo. De cada planta foram tomadas 12 folhas (cada uma do terceiro ou quarto par a partir da extremidade distal de um ramo), 12 ramos (25 cm apicais) e 100 frutos. Foram coletados no total 13.052 ácaros nos dois locais estudados, sendo 7.155 em Jeriquara e 5.897 em Garça. De um total de 108 espécies de ácaros coletados de plantas de café neste estudo, 45 espécies foram observadas em ambos os locais estudados, que apresentaram similaridade de 56%. O número de espécies encontradas exclusivamente em Jeriquara (47) foi aproximadamente três vezes superior ao número de espécies observadas somente em Garça (16). Em Jeriquara, a diversidade foi maior tanto na superfície das folhas, quanto nas domácias, ramos e frutos. Nos dois locais estudados, Brevipalpus phoenicis (Geijskes, 1939) e Oligonychus ilicis (McGregor 1919) foram as espécies de fitófagos mais abundantes e freqüentes. Os estigmeídeos e fitoseídeos foram os ácaros predadores mais abundantes e freqüentes em ambos locais. As espécies mais abundantes e freqüentes de predadores foram Agistemus brasiliensis Matioli, Ueckermann & Oliveira, 2002, Zetzellia malvinae Matioli, Ueckermann & Oliveira, 2002, Euseius citrifolius Den mark & Muma, 1970 e Euseius concordis (Chant 1959) em Jeriquara; e Z. malvinae, E. citrifolius e E. concordis em Graça.Item Life table of Hypothenemus hampei (Ferrari) in relation to coffee berry phenology under Colombian field conditions(Escola Superior de Agricultura "Luiz de Queiroz", 2010-11) Ruiz-Cárdenas, Ramiro; Baker, PeterThe overlap of generations of coffee berry borer (CBB), Hypothenemus hampei (Ferrari) under field conditions in countries like Colombia hinders the construction of life tables by the sampling of natural populations. In this paper, a field methodology to carry out regular measurements of CBB cohorts inside coffee berries of different ages until harvest, both in coffee trees and in infested berries placed on the ground, is developed and used to compare the life history parameters of CBB. Populations with berries at six ages in three experimental stations (without CBB control) and in a commercial farm in Colombia (with chemical CBB control regularly carried out) were used. The duration of the pre-oviposition period as well as the mortality and survival rates of founder females and the proportion of founders leaving infested berries were strongly influenced by the consistency of berries, with optimum conditions for CBB reproduction as from 120-150 days after flowering. No differences were found between stations for the number of CBB developmental stages; but they had larger values than the commercial farm. The latter also had more than twice the average rate of founders leaving infested berries recorded in the stations. Survival functions (cumulative probabilities of survival) for the pest differed among treatments and between the plant and ground micro-environments. Age of berries at infestation was positively related to the intrinsic rate of increase of borer population; whilst generation time and doubling time were inversely related. No differences were found between sites for the main demographic parameters of the pest.Item Effects of acaricides used in coffee crops on the eggs and subsequent stages of green lacewing(Editora UFLA, 2010-01) Vilela, Michelle; Carvalho, Geraldo Andrade; Carvalho, César Freire; Boas, Matheus Alvarenga VilasOne of the most common predatory species in coffee agrosystems is Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae). Its maintenance, however, depends on the application of non-toxic pesticides. Thus, bioassays were carried out in laboratory conditions to evaluate the selectivity of the acaricides spirodiclofen (Envidor – 0.12 g a.i.L -1 ), fenpropathrin (Meothrin 300 – 0.15 and 0.30 g a.i.L -1 ), sulphur (Thiovit Sandoz – 4.0 and 8.0 g a.i.L -1 and, abamectin (Vertimec 18 CE – 0.0067 and 0.0225 g a.i.L -1 ) on this predator’s eggs. The C. externa eggs were directly sprayed using a Potter’s tower. The eggs were then placed in glass tubes and kept in a climatic chamber at 25±2 o C, RH of 70±10% and 12h of photophase. The pesticides were classified according to the recommendations of the IOBC. Fenpropathrin (0.30 g a.i.L -1 ) was harmful and fenpropathrin (0.15 g a.i.L -1 ) was moderately harmful to the green lacewing. The products spirodiclophen, sulphur and abamectin were moderately harmful to the predator. New assays in greenhouse and field conditions should be carried out to verify the toxicity of these compounds.Item Selectivity of agrochemicals on predatory mites (Phytoseiidae) found on coffee plants(Editora UFLA, 2006-04) Reis, Paulo Rebelles; Franco, Renato André; Pedro Neto, Marçal; Teodoro, Adenir VieiraAn evaluation on the effect of agrochemicals to the predatory mites Euseius alatus DeLeon, 1966, Euseius citrifolius Denmark & Muma, 1970, Amblyseius herbicolus (Chant, 1959) and Iphiseiodes zuluagai Denmark & Muma, 1972 (Phytoseiidae) is presented in this paper. These predators are frequently associated to Brevipalpus phoenicis (Geijskes, 1939) (Acari: Tenuipalpidae), vector of the coffee ring spot virus, and to Oligonychus ilicis (McGregor, 1917) (Acari: Tetranychidae) on coffee plants. The residual contact bioassay of spraying in glass surface was used. Twenty-six currently used agrochemicals or those with potential to be used in Brazilian coffee production were tested. Spraying was conducted using a Potter tower at a pressure of 15 lb/pol2; each cover glass received 1.68 ± 0.36 mg/cm2 of the tested products. Adverse effect on the predatory mites was calculated taking into account the mortality of females and the effect in the reproduction during eight days. Tested products were ranked in four toxicity classes according IOBC/WPRS, by the total effect caused to the mite. Five products (fenbutatin oxide, hexythiazox, spiromesifen, spirodiclofen and emamectin) were innocuous or slightly noxious to all predators, whereas three products (abamectin, sulfur and endosulfan) were innocuous or slightly noxious to three of the four predators.