Evolucao da traca da uva Lobesia botrana Schiff. Em vinhas do Ribatejo e Oeste.

English. Lobesia botrana Schiff. and Eupoecilia ambiguella are usually considered as important pests in the Portuguese vineyards, but in fact the first species is the chief one broadly found in the country. During the 1984-1988 period, some experimental work was carried out on the control of the pest, mainly on the efficacy and evaluation of treatments. Pheromone traps were set up in two vineyards in Ribatejo-Tagus Valley and Oeste and adult catches were recorded. Field observations on untreated plots of those vineyards, weekly made, on 100 bunches of grapes at random, could provide data on levels of infestation for the three generations of the pest and considering different stages of development of the insect. The field observation periods of egg-laying, silk threads (1st generation) and attacked bunches of grapes (2nd and 3rd generation), with information on the growth stages of the vineyards for different years and places were drawn. On the basis of this type of information an approach to the life cycle of L. botrana for the regions referred to is made.

PORTUGUES: As tracas de uva Lobesia botrana Schiff. e Eupoecilia ambiguella Hb. sao consideradas normalmente como pragas importantes da vinha. Em Portugal a especie dominante em quase todas as regioes viticolas nacionais e a Lobesia botrana. A Eupoecilia ambiguella parece ter apenas expressao em certas vinhas en zonas limitadas. No periodo de 1984 a 1988 procedemos a montagem de armadilhas sexuais para a captura de adultos em vinhas localizadas respectivamente no Ribatejo (vale do Tejo) e Oeste (Dois Portos). Efectuaram-se tambem observacoes, em regra semanais, sobre parcelas testemunha e sobre talhoes previamente marcados para o efeito. Essas observacoes que incidiram sobre 100 cachos ao acaso, permitiram obter niveis de infestacao nas diferentes fases e geracoes do insecto. As observacoes de ovos e glomerulos (1 geracao) e ovos e bagos (2 e 3 geracoes), sao representados em diagrama ao longo do tempo, referenciados com os estados fenologicos para a (1 geracao). Em face dos elementos obtidos apresenta-se uma aproximacao ao ciclo evolutivo da Lobesia botrana nas regioes referidas.