Effect evaluation and benefit analysis of different trapping methods for fruit flies on sugar oranges

Abstract

Citrus fruit flies are a major kind of quarantine pest that spreads with a potential outbreak in citrus producing areas in Zhaoqing. A variety of fruit flies can be monitored and controlled by physical methods. However, there is a lack of effect evaluation of trapping fruit flies during production. In this study, the effects of different physical trapping methods were tested for bactrocera minax (b. minax) and bactrocera dorsalis (b. dorsalis) in the sugar orange orchards in Zhaoqing. The result showed that in a non-fruiting orchard and fruiting orchard respectively, the numbers of bactrocera dorsalis trapped by sex pheromones were 110 and 32, 25.7 and 6 by food attractants, and 24 and 5 by yellow sticky boards. While the number of bactrocera dorsalis trapped by sex pheromones was significantly higher than that by food attractants and yellow sticky boards, the number of species and quantity of insects trapped by food attractants and yellow sticky boards were, however, higher than by sex pheromones, and bactrocera minax were also trapped. From October to December, there were two peaks of trapped numbers of bactrocera dorsalis, while the number of the bactrocera minax remained stable. In terms of cost per mu, the costs for the first trapping cycle were 55, 40 and 40 yuan per mu by sex pheromones, food attractants and yellow sticky boards respectively, and 15, 40 and 40 yuan per mu after the second trapping cycle. None of the three methods involved contact between lethal chemicals and the fruit. In light of the yearly outbreak due to the life cycles of these two fruit flies, a variety of trapping methods with comprehensive prevention and control measures should be applied starting from the management of non-fruiting orchards, so as to promote pesticide reduction and green plant protection.