Assessing the Potential of Pimenta Racemosa (Mill.) J.W. Moore Leaf Extract As an Attractant for Bactrocera Dorsalis (Hendel) In Selected Mango Plantations in Southern Ghana

Abstract

The oriental fruit fly, Bactrocera dorsalis is an economically important pest known to cause devastating losses to fruits in Sub-Saharan Africa. Several management techniques have been developed of which plant extracts are inspiring great interest due to their availability, reduced cost and risk to humans. The objectives of the study were to compare the attractiveness of different concentrations (5, 3.3 and 2.5% wt/vol) of aqueous leaf extract of Pimenta racemosa with commercial methyl eugenol (Stop Mating Block) and document the distribution of Pimenta racemosa in Southern Ghana. A field work involving trapping was conducted in four selected mango orchards (Prosper, Boko, Ayikuma and Adumanya farms) at the Coastal Savanna ecological zone for the major mango season. The experimental design for trapping was Complete Randomized Block Design (RCBD) with five blocks replicated in the four farms. The insects captured were collected on weekly bases for a period of 14 weeks. A total number of 174,388 organisms were captured with 171,412 identified as B. dorsalis and 2,976 identified as non-target (other insects and spiders). The three different concentrations showed no significant differences (P > 0.05) at Boko, Ayikuma and Adumanya farms but showed significant difference at Prosper farm. No significant differences were observed in the general performance of the different concentrations. Stop Mating Block performed better than the different concentrations with a significant margin across the various farms. Among the locations sampled during the survey studies revealed that Pimenta racemosa is present at Aburi and Ahyiresu both located at Akwapim South district in the Eastern Region. Therefore, the results from the studies suggest that aqueous leaf extract of Pimenta racemosa has the potential to attract field population of Bactrocera dorsalis even at lower concentrations (5, 3.3 and 2.5% wt/vol). Even though Stop Mating Block performed better than the extract, it is economically preferable since most farmers in Ghana are small-holder farmers.