Neem oil (NO), and different formulations of neem oil in a solution of Tetrapleura tetraptera as emulsifier, including neem oil emulsifiable concentrate (NOEC), neem oil slurry emulsifiable concentrate (NOSEC) and 5% NOEC obtained from the seeds of the neem plant, were tested for their efficacy in the control of Maruca testulalis Geyer, under laboratory conditions using flowers of Ife Brown, cowpea variety.
The different concentrations of NOEC (5, 10 and 20%) exhibited a high degree of insecticidal activity on M. testulalis larvae. All the treated flowers were protected from larval damage 2 days after treatment as compared to the 100% damage recorded on untreated flowers and on the flowers treated with T. tetraptera solution alone.
The NOSEC and the 5% NOEC prepared using different volumes of the emulsifier also exhibited some insecticidal activity which decreased with a decrease in concentration. NO/NOEC were superior to NOSEC and the 5% NOEC prepared in different volumes of the emulsifier.