The attractiveness of locally made baits of plant origin for capturing Bactrocera dorsalis and Ceratitis cosyra on mango

Résumé

Introduction – In Nigeria, a majority of mango producers are small holders who cannot afford the cost of imported materials for the management of fruit flies. Sometimes these materials are scarce in the market. The present work reports on the exploitation of local materials for mango fruit fly management. Materials and methods – To produce an oil attractant (CLO) for Ceratitis cosyra, crushed leaves and inflorescences of the local clove Syzygium caryophyllatum were subjected to a hydrodistillation process. The extracted oil, known to contain eugenol, caryophyllene derivatives (sesquiterpenes) and non-phenolic compounds, was subjected to chemical treatments to isolate eugenol. The eugenol was further used to synthesize local methyl eugenol (LME) for attracting Bactrocera dorsalis. The attractiveness of (a) CLO and terpinyl acetate (TA) to Ceratitis cosyra, and (b) LME and commercial methyl eugenol (ME) to Bactrocera dorsalis were compared in a 2-ha mango orchard. Tephri traps separately baited with the test attractants were hung on mango trees separated by 50-m intervals. The arrangement was a randomized complete block with three replicates. Results and discussion – A significantly (P<0.05) higher number of C. cosyra was captured in CLO traps compared to those of TA in 10 weeks (3.8 against 1.7 flies trap^-1 day^-1). In the same period, there was no significant (P>0.05) difference between the number of B. dorsalis caught in commercial ME traps compared to those of LME (8 flies trap^-1 day^-1 and 5.5 flies trap^-1 day^-1, respectively). However, CLO and LME attracted a negligible number of other fruit fly species. Conclusion – As an alternative to imported or conventional baits for capturing Bactrocera dorsalis and Ceratitis cosyra, locally produced homologues, methyl eugenol, and clove oil can be utilized respectively.