Field assessment of the impact of farmers’ practices and cacao growing environment on mirid abundance and their damage under unshaded conditions in the southern Cameroon

Mirid populations and their damage on cacao production have been widely studied under shaded conditions worldwide. There is a lack of information on the mirid populations and their damage under unshaded conditions. To reach that goal, we assessed biweekly mirid abundance through visual counts of individuals and their damage via scoring dry leaves on branches and cankers on twigs and trunks of trees, in nine farms across three agrosystems in Cameroon during two consecutive years. It was found that all mirid individuals belonged to the species Sahlbergella singularis (Hemiptera: Miridae); their mean number was low (0.08 mirid tree −1 for year 1 and 0.23 mirid tree −1 for year 2) and precisely lower in the Savannah zone (0.27 mirid tree −1 ) than transition (0.63 mirid tree −1 ) and forest zones (0.55 mirid tree −1 ). The mirid damage varied significantly ( p