Ocorrência de moscas da fruta na manga em Maputo - passado e presente

Abstract

Fruit flies are invasive and polyphagous pests of great economic and agricultural importance worldwide, causing significant damage to fruits and vegetables, representing a challenge for producers, as their attack causes holes in the fruit, rotting, premature and abundant fall of the fruit, affecting production and marketing. Since the introduction of the invasive species Bactrocera dorsalis in Mozambique, specifically in the province of Niassa in 2007, and in Maputo, where the first reports began in 2012, several studies have been carried out and different control methods have been recommended. However, after more than 10 years, there is no before and after analysis of the situation of fruit fly infestation, which would help to evaluate the success of management measures. In this vein, the present study was carried out with the aim of carrying out a comprehensive assessment of the population density, the level of infestation and the damage caused by fruit flies in the past and present in Maputo. 119 mangoes were collected on December 16, 2022 and January 26, 2023 at the Umbeluzi Agricultural Station, and 2 traps with methyl eugenol attractant were set up and monitored on the day of the 1st fruit collection. All collected fruits were weighed and incubated in the Entomology Laboratory of the Faculty of Agronomy and Forestry Engineering – UEM. The estimated variables were: density (flies per trap per day), % infestation, % emergence, species abundance, % emergence and infestation rates (pupae/fruits, pupae/kg, adults/fruits and adults/kg). The data obtained were compared with data from the 2021/22, 2016/17 and 2014/15 mango harvests collected by other authors in the same location and same host and were analyzed in STATA 14. The highest population density was recorded by the species Bactrocera dorsalis which had 110.36 and 120.14 flies/trap/day for the months of December and January respectively, with this harvest (2022/23) being the one that recorded the highest density and 2021/22 the lowest density. The species Bactrocera dorsalis and Ceratitis cosyra were the most abundant, especially between 2021-2023, where the first stood out for being the most abundant in capture traps. The infestation percentage for the 2022/23 campaign was 63.03%, 50% in 2016/17, 44.72% in 2021/22 and in 2014/15 an infestation of 68.97% was recorded. In terms of adult emergencies, the 2022/23 campaign recorded the highest % of adult emergencies (77%). These results indicate that the sampled points continue to register high infestation year after year, suggesting the need to reinforce the implementation of management measures.