Plant extracts 95% confidence limit LC90 (ppm) 95% confidence limit χ2 (df =4) Slope + SE LCL UCL LCL UCL Aloe pirottae 76.344 31.47 105.42 133.39 104.59 249.5 3.7109* 0.022 ± 0.003 Acokanthera schimperi 282.76 135.1 338.93 407.93 399.19 610.02 6.6342* 0.01 ± 0.001

Table 3: Larvicidal activity of methanolic extract of the two local plants, Aloe pirottae and Acokanthera schimperi against fourth instar larvae of Anopheles arabiensis with its respective lethal concentrations, confidence intervals (95%), chi-square, slope and standard error after 24 hour of exposure