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

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

INSECTICIDE HANDLING IN COCOA PRODUCTION IN FOUR REGIONS IN GHANA

Management of insect pests of cocoa (Theobroma cacao L.) using insecticides began in 1950 and has since gone through various programmes with concomitant challenges and successes. Presently Imidacloprid (Confidor®), Bifenthrin (Akatemaster®) and Thiamethoxam (Actara®)are recommended by Ghana Cocoa Board (COCOBOD) for the management of insect pests. A survey was conducted in the Ashanti, Eastern, Volta and Western Regions of Ghana using questionnaires and farm visits of 147 cocoa farmers’ fields to gather information on the characteristics of the farmers and insecticide handling and use by respondents. The survey showed that males dominated cocoa farming (72.7%) and most of them aged between 50 and 60 years. About 44% have had basic education whilst 37.5% of them belonged to farmer based organizations. About 52.8% of the farmers own motorized mistblower but 47.2% of the farmers use knapsack in the absence of a mistblower. About 44.8% do their own spray application whereas 55.2% hire labour. About 60.9% of the population across the regions read the label on the insecticides before application. A few (31.6 %) of the respondents put on the full personal protective costume during insecticide application and 21.9% do not use any protection. There was a positive correlation between farmers’ membership of farmer-based organisation and the costume-wearing farmers in the Ashanti, Eastern and Volta Regions and it was significant in the Ashanti region. It isrecommended that training and monitoring programmes be organized for farmers on the need to handle pesticides properly for personal and environmental safety and consumer benefit.Keywords: Insecticides; pest management; cocoa farmers; safet

Tamarixia radiata global distribution to current and future climate using the climate change experiment (CLIMEX) model

Abstract The phloem-limited bacteria, “Candidatus Liberibacter asiaticus” and “Ca. L. americanus”, are the causal pathogens responsible for Huanglongbing (HLB). The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) is the principal vector of these “Ca. Liberibacter” species. Though Tamarixia radiata Waterston (Hymenoptera: Eulophidae) has been useful in biological control programmes against D. citri, information on its global distribution remains vague. Using the Climate Change Experiment (CLIMEX) model, the potential global distribution of T. radiata under the 2050s, 2070s, and 2090s for Special Report on Emissions Scenarios A1B and A2 was defined globally. The results showed that habitat suitability for T. radiata covered Africa, Asia, Europe, Oceania, and the Americas. The model predicted climate suitable areas for T. radiata beyond its presently known native and non-native areas. The new locations predicted to have habitat suitability for T. radiata included parts of Europe and Oceania. Under the different climate change scenarios, the model predicted contraction of high habitat suitability (EI > 30) for T. radiata from the 2050s to the 2090s. Nevertheless, the distribution maps created using the CLIMEX model may be helpful in the search for and release of T. radiata in new regions