Influence of Abiotic Factors on the Population of Serangium Parcesetosum; A Predator of Cassava Whitefly in Uganda

Whitefly is a known pest of economic importance in the cassava production systems of Africa. This pest has been reported to cause losses to cassava through direct feeding damage as well as vectoring cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). Serangium parcesetosum is a known predator of whitefly (Bemisia tabaci) and previous screenhouse and laboratory studies reported that temperature affected the reproduction and survival of this predator. However, these findings lacked precision since they did not depict the field situation. In that regard, it was imperative to initiate a study to help understand the influence of abiotic factors especially temperature and rainfall on the population of S. parcesetosum in the cassava growing fields of Uganda. The study was conducted in two agro-ecological zones of Uganda, namely; North Western Savannah Grassland (Lira) and the Kyoga Plains (Kamuli) in the first rains of 2017. Results revealed that temperature caused an increment of 3.5%, 9.1% (Kamuli) and 1.1%, 1.8% (Lira) for mean adult and larvae S. parcesesotum per plant respectively. On the contrary, rainfall caused a decrease in the population of S. parcesesotum in Lira. Generally, the effect of both temperature and rainfall on the predator population in the field was minimal.