Field-based Evidence of the Black Coffee Twig Borer infesting Maesopsis eminii in Coffee Agro-systems in Kiboga District, Uganda

Abstract

Abstract. Despite Ugandan coffee farmers’ preference for Maesopsis eminii as a shade tree, the
species is an alternate host for the black coffee twig borer, Xylosandrus compactus (Eichhoff)—a
major insect pest of coffee in the country. Wilting and drying of leaves and branches of young M.
eminii trees (<5 m tall) observed in Kiboga District, Uganda. The branches were trimmed off the
trees, separated into primary and secondary branches and then the percentage of those possessing
characteristic X. compactus entry holes determined separately. Additionally, the number of entry
holes on both primary and secondly branches was established to determine the extent of damage of
X. compactus. X. compactus characteristic holes were observed on both primary and secondary
branches of M. eminii - percentage of branches having entry holes and the number of entry holes
higher on primary than secondary branches. Dissecting the branches at the entry holes revealed
various life stages of X.compactus in the gallery, proving that the damage was due to the pest.
Presence of this pest on trees that are inter-planted in the coffee agroforestry systems presents a
dilemma in managing it. Therefore, research should be geared towards designing management
strategies for the pest in the coffee agroforestry systems. In the meantime, farmers should always
trim-off and burn all infested parts from coffee and other plants inter-planted in it.