Diversity and abundance of thrips species on bananas from different ecological zones in Embu County, Kenya

Thrips are among the important pests infecting banana production systems because they have a direct effect on the banana fingers. A prerequisite to the development of any pest management strategy is the correct identification and determination of the pest species attacking crops. A field study was carried out to determine the diversity and abundance of thrips on banana plantations in Embu County, Kenya. The study was conducted in three agroecological zones, namely, Upper Highland UM1, Mid Highland UM2, and Lower Highland UM3 in two seasons in 2015. A total of 878 individual thrips belonging to two families (Thripidae, 12 species, and Phlaeothripidae, one species) were collected and identified. Frankliniella schultzei (Trybom) was the most abundant species, with 392 of the total individuals recorded (species dominance = 44.65%) followed by Megalurothrips sjostedti (Trybom) with 250 individuals (species dominance = 28.47%), while Dendrothrips sp. was the least abundant with only one individual recorded (0.11%). F. schultzei, M. sjostedti, F. occidentalis (Pergande), and Haplothrips godweyi (Franklin) were well distributed across the different zones during the two seasons. Overall species diversity was highest in the lower zone Shannon-Weiner (H’=1.654) and Simpson’s diversity index (1-D=0.740) followed by the middle zone with Hʹ=1.620 and 1-D=0.730 while the upper zone had the lowest diversity (H’=1.332) and (1-D=0.623). A high similarity of 0.8-0.82 and 0.67-0.69, according to Jaccard’s and Sørensen’s similarity index, respectively, was reported between all the sites, indicating that all the sites had the same level of similarity in the number of shared species. In conclusion, we report that bananas are infested by a wider array of thrips species than previously thought. F. schultzei and M. sjostedti are the major thrips species infesting bananas in the study area across all seasons and agroecological zones and should be the main targets for pest management interventions.