8 resultados para Mealybug Mummitication

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


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The citrus-growing ecosystem houses a great deal of species of natural enemies, among them Chrysoperla externa (Hagen, 1861), which presents a great potential for use in the biological control of pests. The aim of this work was to evaluate the effects of the preys Planococcus citri (Risso, 1813) and Toxoptera citricida (Kirkaldy, 1907) on the development of larva and pupa of C. externa. The trial was carried out in an acclimatized room at 25 +/- 1 degrees C, 70 +/- 10% RH and 12-hour photophase, the treatments consisting of the continuous and alternate supply of those two preys in each instar of the predator, in addition to eggs of Anagasta kuehniella (Zeller, 1879) utilized for comparison purposes. Both the white mealybug and the aphids were given in sufficient amounts to the C. externa larvae to be able to feed ad libitum. The lifetime and the survival rate of the phases of larva, pupa and the larval-adult period of C. externa were evaluated. It was found that T. citricida given either singly along the larval development or in two consecutive instars of the predator was not an adequate prey, 100% of mortality over the larval-adult period being found. When the larvae fed on P. citri, given in two instars of the predator, the survival rate in the larval-adult period was similar to the diet constituted of only A. kuehniella eggs, except when fed with T. citricida in the first instar.

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A cochonilha Planococcus citri (Risso, 1813) suga a seiva dos botões florais e frutos do cafeeiro, atacando as rosetas desde a floração até a colheita. Embora seja relatada há alguns anos na cafeicultura, são escassas as informações sobre o desenvolvimento dessa cochonilha em cafeeiros. Assim, o presente trabalho teve por objetivos avaliar alguns aspectos biológicos da fase ninfal de P. citri em plantas de café. Ovos dessa cochonilha foram retirados de uma criação em laboratório, isolados em placas de Petri contendo discos foliares de Coffea arabica L., das cultivares Acaiá Cerrado, Mundo Novo e Catuaí Vermelho e de C. canephora Pierre & Froenher, cultivar Apoatã. As placas foram mantidas em câmara climatizada a 25 ± 1ºC, 70 ± 10% de umidade relativa e 12h de fotofase. Constatou-se que a cultivar Catuaí Vermelho foi a que proporcionou maior duração do período ninfal das fêmeas, porém, não foram constatadas diferenças na mortalidade. Essa cochonilha se desenvolveu satisfatoriamente em todas as cultivares de café estudadas e os resultados não mostraram diferenças claras de susceptibilidade.

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The citrus mealybug, Planococcus citri is an important pest attacking several crops. Biotic and abiotic factors, as well as the substrate they feed on influence its population. The present study was aimed to study the effect of some feeding substrates on mealybug development in laboratory conditions. Leaf disks of guava, fig and cherimoya were placed individually on an agar film inside a Petri dish. One egg of the insect was confined inside each container, replicated 60 times for each treatment. Containers were kept in a climatized chamber at 25[degree] C, 70 [plus or minus] 10% RH and 12 hours photophase. Insects reared on guava leaves showed a longer nymphal development, while the female longevity was longer on fig leaves. However, no statistical differences were found in the survival index, which showed values higher than 83%, suggesting that all substrates studied here were adequate for the development of P. citri.

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The longtailed mealybug Pseudococcus longispinus (Targioni Tozzetti, 1867) (Hemiptera: Pseudococcidae) has been reported attacking coffee crops causing fruit fall in the State of Minas Gerais, Brazil. The knowledge of the population dynamic of this pest is then necessary to implement control measures. Its development was studied at temperatures of 15, 20, 25, 30 and 35°C, determining the thermal requirements. The insects were confined inside a Petri dish containing a foliar disc of 4 cm diameter of Coffea arabica L., cultivar 'Acaiá Cerrado'. The temperature affected the P. longispinus development and survival. Few insects survived at temperatures of 15 and 30°C, and 100% of mortality was obtained at 35°C. The duration of the nymphal stage was reduced when the temperature was increased from 20 to 25°C, with a survival rate of 80% at both temperatures. The thermal parameters varied according to the development stage of the mealybug and the base temperature was fixed at 8.0 °C for the nymphal stage of females, a thermal constant of 422.1 day degrees and number of generations increased with rising temperature. The optimal temperature for the insect development was 25°C.

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The cultivation of grapes is one of the most traditional cultures and the world's oldest one. In Brazil, cultivars occupy an area of approximately 90 thousand hectares, covering the south, southeast and northeast, in latitudes ranging from 30 º 56 '15''S up to 5 º 11' 15''S. The culture of the vine may be the target of the attack of some diseases and pests, and currently the main concern for growers is the subterranean mealybug, Eurhizococcus brasiliensis (Hemiptera: Margarodidae), known as pearl-ground. This arthropod infests the roots causing a progressive languish of the vine, even causes its death. In southern Brazil it is known that some species of ants can disperse pearl-ground for short distances, however, there is no information about that in the State of Sao Paulo. Thus, it is extremely important to perform studies with this focus on wine regions in this State. Therefore, this study aimed to identify the species of underground ant community in different grape varieties found in vineyards in the town of São Roque – SP, Brazil. With that purpose, samples were collected within one year. We used underground pitfalls spread across twelve points. In each of the points were placed two traps, one containing honey and the other containing sardine as attractive. The results revealed the presence of three morphospecies of ants in Niágara Rosada and four in other grape varieties, there was no significant difference in the species richness among the cultivars (Kruskal-Wallis - 0.33, p = 0.5). In both trials, the most frequent species was Brachymyrmex sp.4, suggesting that there is no dominance of distinct species of Niágara Rosada and the other grape varieties. There was no dissimilarity in species richness of the ones visiting honey or sardines (Kruskal-Wallis - 0.08, p = 0.7) and the analysis of variance indicated a great similarity in species richness between the rainy and dry seasons (Kruskal-Wallis - 0.09, p = 0.7)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)