Preliminary studies on the damage symptoms and the spatial distribution of an emerging insect pest, Mecocorynus sp. (Coleoptera: Anthribidae) on cashew in Ghana

Cashew (Anacardium occidentale Linn.) has become a very important non-traditional tree crop in Ghana. The crop is, however, infested by numerous insect pests at different stages of its growth. Knowledge of the insect complexity associated with the tree is essential for developing pest control strategies for the crop. Following a reported outbreak of an unknown pest by officials of Ministry of Food and Agriculture (MOFA) and farmers in March 2009 in some cashew plantations in the Brong- Ahafo Region, an investigation was initiated to collect and identify the insect species involved and assess the extent of the damage caused by the insect. The cashew bark borer, Mecocorynus sp. (Coleoptera: Anthribidae) was identified and found to be responsible for the damage and could kill the attacked trees within weeks after infestation. Observations at Jaman south and Jaman north of death of mature trees within few weeks of infestation were indications of emergence of new pest of cashew in Ghana. Studies on the distribution and damage characteristics of the pest was conducted from April 2009 to December 2010 in 41 major cashew growing areas within five districts of the Brong-Ahafo Region. In the Jaman South District, symptoms of infestation of the insect were found on 14.2% of the tree population and the death rate of tree population was 2.2%.The incidence of the pest in the Jaman north was also high, with death rate of 2.8% and infestation rate of 13.6%. In the Tain district death rate was 0.6%; infestation was observed only at Banda-Biema, Nsawkaw, Mendji, Donkokrom and Brodi. This paper reports the status of a new emerging pest of cashew in Ghana, which needs an urgent attention.