Aphid damage to field beans in relation to population dynamics and ecological conditions.
Aphid populations were studied on field beans [Vicia faba] in Hungary in 1986-87. The rapid population increase in 1986 was attributed to high temperatures (16.8-17.6°C) in the last 10 days of April and in May. In 1987, the average temperature was 11.1-13.3°C during this period. Aphid reproduction began at the beginning of June. Rainfall during May 1987 (125.1 mm) prevented population increase. Aphis fabae, A. craccivora and Acyrthosiphon pisum were common, 1080.4, 22.3 and 12.3 aphids/plant, respectively, being recorded for these species in 1986. Aphis fabae was most numerous during the first half of the growing period, while Acyrthosiphon pisum became dominant after flowering. The yield of plots treated with Thimet 10 G [phorate] was 54 and 15% higher than in untreated plots in 1986 and 1987, respectively.