Correlating the infestation of fruit flies (Diptera: Tephritidae and Loncheidae) to the guava, peach and loquat trees phenology / Infestação de moscas-das-frutas (Diptera: Tephritidae e Lonchaeidae) relacionada à fenologia da goiabeira (Psidium guajava L.), nespereira (Eriobotrya japonica Lindl.) e do pessegueiro (Prunus persica Batsch)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

Field experiments were conducted in three orchards in Monte Alegre do Sul, SP, each containing either a collection of strains of peach (September to October), guava (January to April) or loquat (August to September), during 2002 and 2003. Three strains of guava (Guanabara, L7P28 and 252), two of loquat (Precoce Campinas and Precoce 264-54) and three of peach (Aurora 2, Dourado 1 and Régis) were used for infestation assessment. Guava and loquat fruits were bagged and unbagged biweekly and weekly, respectively, for the assessment of the infestation period and only weekly for the peach. In all cases, fruits were bagged at the beginning of their development, while still green. A sample of 30 bagged fruits were unbagged weekly (loquat and peach) or biweekly (guava) until fruits were completely ripe, from a total of 500 (guava) and 400 (loquat) fruits. Fruits were measured and a sample was taken for physicochemical analysis. Fruits were harvested once they were ripe, taken to the laboratory, weighted and measured. They were placed into plastic cups half-filled with sand and covered with a fine fabric to allow for field-collected fly development. Three McPhail traps containing Torula yeast (food attractant) were hung from January/2002 to January/2004 to assess the population fluctuation of fruit flies in each orchard. Five tephritids and eight lonchaeids species emerged from field-collected fruits maintained in the lab. Five species each of braconid and figitid fruit fly parasitoids were also observed emerging from these fruits. Ceratitis capitata showed a sazonal behavior with population density peaking at the second semester. It was also observed that Anastrepha spp. and lonchaeids remained in the orchards throughout the year. All three host fruits larger than 2 cm in diameter were infested by fruit flies at the early stages of development. Fruit infestation increased in all orchards as fruit development occurred with the highest infestation level observed at the end of the ripening. Physical parameters, such as size, firmness, brix and color were more reliable in estimating fruit susceptibility to fruit-flies than the chemical parameters evaluated (pH, acidity and humidity) for all three host fruits. The ecological aspects of the infestation of fruits by fruit flies and the tritrophic interactions (parasitoid/fruit fly/fruit) were discussed.

ASSUNTO(S)

mosca-das-frutas biological control mediterranean fruit fly or medfly guava peach pêssego loquat fruit fly nêspera mosca-do-mediterrâneo goiaba insect host relation controle biológico relação hospedeiro-inseto

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