Diversity And Abundance Of Insects At Different Heights In Cocoa Farms.

Abstract

The usage of traps at a single stratum has mostly been investigated, which may underestimate or misrepresent the true abundance of insect species. Flowers along the stems, of cocoa trees, spreading out through the branches into the canopy, makes it unique and therefore may attract insects along its entire length. The goal of this study was to access the diversity and abundance of insects at different heights in cocoa farms. Pan traps consisting of yellow, blue and white colors were set at 3.0 m, 1.5 m, and 0.0 m on cocoa trees in three cocoa farms in the North-Eastern part of the Ashanti region. A total of 25,470 insects belonging to 87 species, 62 families, and 12 orders were catalogued and ranked. Thysanoptera was the most prevalent insect order, with 9,601 (37.7%), followed by Diptera with 7,079 (27.79%), and Hymenoptera with 6,101 (23.95 %). The three most dominant insect orders put together constituted between 62 – 95 % of the total coloured pan trap catches. The yellow pan traps proved to be the most effective, in terms of diversity of insects collected at the upper (3.0 m), middle \ (1.5 m) and lower (0.0 m) levels. The white pan traps performed better than the other traps at 1.5 m and 3.0 m. The white pan traps had the highest abundance of insects at 3.0 m and 1.5 m but for blue traps, height had little effect on its insect catches. Though there were no significant differences in insect abundance at different heights and trap performance, there were variations in total insect catches at the different levels and to pan trap colour. Knowledge on the distribution and collections of insects would help to control or conserve their numbers in a more systematic way and which can be a good reference in future, making sampling easier and increasing reliability. At different heights it could inform levels at which insect groups are likely to be concentrated, between times and seasons. This could be useful in pest management practices, as well as suggesting monitoring and sampling protocols future research activities. Note: Height = Vertical level keywords: Insect diversity & abundance, heights, cocoa, pan traps.