Spatial Distribution And Temporal Abundance Variations Of Three Important Insect Pests Of Coffee In Kilimanjaro Region, Tanzania

ABSTRACT

Studies on spatial and temporal distribution of white coffee stem borer (WCSB), antestia bug and coffee berry borer (CBB) were carried out between September 2007 and August 2008 in medium altitude (Lyamungo) and high altitude (Kilema) areas in Kilimanjaro region. Specifically, the study aimed at establishing the species composition and spatial distribution, the temporal variation in abundance, and the relative importance of three pests in coffee ecosystems. A multistage random sampling method was used to select farms in two locations where in each location, one ward was selected and within each ward three villages were chosen, and in each village fifteen farms were randomly selected for the study. In each farm, nine trees were selected to make a total sample size of 810 trees. Insects’ were counted every month to establish their population dynamics. WCSB was dominant in both high and medium altitudes while antestia bugs were dominant at medium altitude and less dominant in high altitude. CBB was dominant at medium altitude and no records were noted in the high altitude. High population of antestia bug and CBB were recorded during the short and long rains when flowers and fruit developments were set. WCSB were also observed to increase gradually during short and long rains, which was established as their reproduction period. WCSB was found to be more damaging (44.8 to 67.7 %) than CBB (0 to 12.5%). The study shows that WCSB was more prevalent in the sparse shade while antestia bug and CBB were more prevalent in dense shade. Since WCSB is abundant in all locations and was the most damaging insect pest in the study area, it is recommended that more attention should be focused on management of this pest