Incipient bifenthrin-resistance in field populations of cocoa mirids, Distantiella theobroma (Dist.) and Sahlbergella singularis Hagl. (Hemiptera: Miridae)

Abstract

Bifenthrin is one of the insecticides approved by the Ghana Cocoa Board (COCOBOD) for the control of cocoa mirids. Bifenthrin-resistance levels of D. theobroma and S. singularis collected from different locations in the Eastern Region (ER), Volta Region (VR) and Central Region (CR) were determined by calculating their resistance ratios (RRs). The highest RRs for S. singularis were recorded from New Tafo in the ER and Logba Alikpati in the VR, which displayed 6-fold and 6.2- fold bifenthrin-resistance, respectively. Populations of S. singularis from Pankese in the ER and Likpe in the VR also displayed 3.6-fold and 3.9-fold bifenthrin-resistance, respectively. The D. theobroma population that displayed the highest bifenthrin-resistance of 3.7-fold was from New Tafo. The results show incipient bifenthrin-resistance in field populations of D. theobroma and S. singularis, which requires the implementation of effective resistance management strategies to prevent full-blown resistance in the cocoa mirids.