Captura massal como estratégia de manejo de Anastrepha fraterculus (Diptera: Tephritidae) na cultura da macieira

Abstract

The South American fruit fly Anastrepha fraterculus (Wied., 1830) (Diptera: Tephritidae) is one of the main pests associated with apple culture in southern Brazil. The predominant strategy in the management of A. fraterculus populations is through the use of chemical insecticides, especially organophosphates, in the form of spray coatings or toxic bait formulations. Although it is effective, the use of phosphorus insecticides presents restrictions with emphasis on toxicity to the applicators and residues in the fruits. Safer management strategies are studied worldwide in order to reduce the use of chemical molecules in order to expand the alternatives for Integrated Pest Management (IPM). In this work, mass trapping was evaluated as a strategy for population suppression of adults of A. fraterculus in apple orchards cultivated with and without anti-hail screen coverage. The work was conducted during the 2017/2018 and 2018/2019 crops in four commercial apple areas called A1, A2, A3 and A4, located in the city of Vacaria/RS. Areas A1 and A2 were cultivated without anti-hail screen cover, and areas A3 and A4 are cultivated under anti-hail screen protection. In the areas where mass trapping was used, 120 traps per hectare (A1 and A3) made with PET bottles (600mL) baited with 300mL of hydrolyzed protein CeraTrap® were used. The remaining two areas (A2 and A4) were managed with the application of insecticides in coverage (conventional management), with emphasis on the organophosphate insecticides methidathion and phosmet, and the mixture of acetamiprid + etophenproxy. Adult population fluctuation was assessed weekly using McPhail traps baited with 25% grape juice and CeraTrap® . Damage to fruits (galleries) was evaluated every two weeks by harvesting 500 to 1000 fruits per study area. In areas managed with mass trapping, the number of adults of fruit flies caught in McPhail monitoring traps was lower than conventional management. In areas with anti-hail screen protection, the infestation of A. fraterculus adults was considered low, since the level of control of the 0.5 FTD species was exceeded only once during the two evaluated harvests. Grape juice at 25% showed greater efficiency in capturing adults of A. fraterculus in the fruit growth phase (December to January). From that period on, CeraTrap® was more efficient in catching adults of A. fraterculus. During the 2017/2018 and 2018/2019 crops, an average of 0.4% of damaged fruits (galleries) caused by A. fraterculus in area A1 was obtained, and 1.7% and 0.4% in the area A2, in the 2017/2018 and 2018/2019 crops, respectively. In area A3 the damage was 0.6% and 0.7% compared to 0.8% and 0.5% in conventional management (A4). It was concluded that mass trapping was effective in maintaining and suppressing the adult population of A. fraterculus below the level of control during the period of ripening and harvesting of apple fruits. And the presence of antihail screen reduces the infestation of A. fraterculus adults in apple orchards.