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Percorrer por autor "Lopes, J."

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  • Biological control of Prays Oleae (BERN.) By chrysopids in tras-os-Montes region (Northeastern Portugal)
    Publication . Bento, Albino; Lopes, J.; Torres, L.; Passos-Coelho, P.
    A study was carried out in an olive grove in the Tras-os-Montes region, in the period 1993 to 1996 to establish the rate of predation of chrysopids on Prays oleae (Bern.) eggs. Data on a trial conducted in 1996 to evaluate the effectiveness of field releases of Chrysoperla carnea (Steph.) in controlling eggs of the carpophagous generation of the pest are also reported. Six species of Chrysopidae have been collected. The most abundant were C. carnea and Mallada flavifrons (Brauer) which together represented about 74% of total captures. The main period of adult catches occurred between July and October. The rate of predation by chrysopids on P. oleae eggs varied among different generations of the pest and in different years, reaching 34% for the carpophagous generation in 1996. The potential damage that might be expected from the studied population of P. oleae was almost halved by releasing 360 larvae of C. carnea per tree.
    1999Comunicação em conferência Acesso aberto Ver mais
  • A contribution to the knowledge of Bactrocera oleae (GMEL) in Tras-os-Montes region (northeastern Portugal): phenology, losses and control
    Publication . Bento, Albino; Torres, L.; Lopes, J.; Sismeiro, R.
    Severe damage is caused by the olive fly (Bactrocera oleae (Gmel)) in the Trás-osMontes region. In order to develop a control strategy, two olive groves for oil production ("Cobrançosa" and "Verdeal") and one for table olive ("Negrinha de Freixo") were assessed ( 1993-1996). The insect phenology, yield losses and fruit infestation were evaluated. The insect's peak flight period occurred during the first half of October. Severe yield losses due to the pest occurred in 1995, reaching 19 % of the total harvest. It is concluded that earlier harvesting (second half of September) can avoid substantial losses because the main period of infestation in all years occurred in October.
    1999Artigo científico Acesso aberto Ver mais