Efficacy of Local Food Baits in Fruit Fly Monitoring and Trap Based Estimation of Adults’ Infestation Index in Guavas in Maputo, Mozambique

Fruit flies (Diptera: Tephritidae) are major pests of crops, requiring effective monitoring for management. This study evaluated locally available food baits for monitoring fruit flies in guava orchards in Maputo, Mozambique. It also assessed infestation levels, examined the relationship between trap catches and adult/kg from incubated fruits. A randomized block design with four treatments (palm sap, molasses, torula yeast, and water) and four replications were used. Tephri traps were installed on four trees per block and inspected weekly, while guava fruits from trees and the ground were collected and incubated to estimate infestation indices. Data on flies’ density was subjected to ANOVA for analysis, to compare the treatments. Three genera (Bactrocera, Dacus, and Ceratitis) were recorded, with high relative abundance (90.37%) for Bactrocera dorsalis. Torula and palm sap were the best attractants, with no significant difference between them. Guava fruits showed high infestation (208.46±13.34 adults/kg). Trap catches of B. dorsalis were positively correlated with adults/kg, explaining 42.5% of infestation variation, highlighting the effect of the “outside the orchard” factors in the infestation indices. Results show that palm sap is a promising low-cost alternative bait and highlight the importance of considering area wide management of fruit flies.