Assessing the efficacy of integrated pest management strategies for suppressing Bactrocera invadens in selected orchards in Manica Province, Mozambique

The invasive fruit fly, Bactrocera invadens, was first detected in Mozambique in 2007 (Cuamba District, Niassa Province) and is now well established and widespread in the North and central regions. Direct damage to mango and guava due to B. invadens has been reported to range from 56.5% to 92.5% in the Northern Province of Cabo Delgado. In addition to the direct losses, indirect losses due to quarantine restrictions have been enormous since the occurrence of B. invadens has led to the suspension of fruit and vegetable exports to the country’s major trading partners. To overcome the impact of B. invadens, in Mozambique, the use of integrated fruit fly management strategies for fruit fly population suppression has been applied by farmers, combining GF-120, bait spray, HymLure (food attractants combined with Malathion insecticide), male annihilation and orchard sanitation. The efficacy of IPM measures was assessed by comparing B. invadens population between the IPM treated farms and not IPM treated (control plot). Adult B. invadens population size was monitored at monthly basis using ME baited traps. During the 2012/2013 season, the mean population density of 0.4 flies per trap per day was much lower compared to the 8.5 flies captured in the control farms (with no IPM strategies application) corresponding to 95.5% population reduction on the IPM treated farms. These results suggest that B. invadens population can effectively be suppressed through a combination of management measures in an orchard and this combination of IPM strategies could be exploited for a large scale application in the country.