Evaluation Of Two Trap Types And Two Attractants For Mango Stone Weevil Sternochetus Mangiferae (F) (Coleoptera: Curculionidae) In Three Districts In Southern Ghana

ABSTRACT The Black pyramid and Circle traps were evaluated with single and double combinations of gas chromatography grade of benzaldehyde (BZ) and essential oil (EO) obtained from the mango blossom to determine their performance in attracting the mango stone weevil in three commercial mango orchards located at Ayikuma, Kpong and Somanya all in Southern Ghana. Eight trap and lure treatment combinations consisting of (Pyramid trap only, Pyramid trap + BZ, Pyramid trap + EO, Pyramid trap + BZ + EO, Circle trap only, Circle trap + BZ, Circle trap + EO and Circle trap + BZ + EO) were evaluated in a randomized complete block design. The number of mango weevils captured during each week of sampling was used as a measure for trap effectiveness. A total of 14 mango stone weevils were recorded by the various traps and lure combinations in all the three study sites. The Black pyramid trap captured more of the stone weevils (about 6-fold) compared to the Circle traps. The ANOVA results showed that there were significant differences among the locations, trap type, lure type and the interaction between trap type and lure type. The interaction however, among location*trap type, location*lure type and location*trap type*lure type were not significant. The trap performance was not improved by addition of the attractants. Stone weevil damage ranged between 54.5 and 92.9 % at Ayikuma and Kpong respectively. The effect of temperature and humidity on trap and lure performance could not be determined in this study due to zero trap capture during the major mango fruiting season. Intensive spraying of the orchards, low stone weevil populations, high concentrations of host plant volatiles released in the orchards, the possibility of the stone weevils escaping from the pyramid traps, and the fact that the essential oils used in this work was just a crude extract; are some of the reasons which could have accounted for the low trap captures.