Identification of flower visitors of African sandalwood (osyris lanceolata) in natural habitats and agro ecosystems a case study of Bugesera region, Burundi

The study involved the identification of the flower visitors of African Sandalwood (Osyris lanceolata) in natural habitats and agro-ecosystem in Bugesera region (Burundi). The plant species is known worldwide because of its ecological and economic importance; and because it is threatened by heavy exploitation in the wild. The study area is also a densely populated area, and this puts high pressure on the natural habitats. Two types of habitat (natural and agroecosystem) were involved in the study. Murehe NF and APRN were natural while Mutwenzi CAPM and Bugabira were in agroecosystem. Flower visitors of 16 trees of O. lanceolata have been assessed. Visual observation and sweep net methods have been used. A total of 341 insects have been recorded on O. lanceolata flowers. Insects were classified into 5 common Orders, viz Hymenoptera, Diptera, Coleoptera, Lepidoptera and Hemiptera. The agroecosystem showed to be more abundant in flower visitors than natural habitat with 62 % and 38% respectively and the difference was statistically different. (Mann Whitney U =1462.500, p = 0.006). The natural habitat showed to be more diverse than agro-ecosystem and also the difference was statistically significant (Delta = 2.026, p=0,012). The similarity of the 2 sites in flower visitors was 71%. Flower visitors showed to be diurnal and their activity was high in morning hours from 08.00 to 11.00 hours. It is concluded that the ongoing poaching of O. lanceolata affects the trees and it’s flower visitors. Poaching does so by destroying the floral resources and habitat for flower visitors. Natural habitat has showed also to be resilient to some extent to destructive human activities. Time management of agricultural practices such as spraying should also be well planned not to interfere with flower visitors activities