DOI: 10.36347/sajb.2017.v05i04.002

Pages: 264-270

Ootheca mutabilis which was considered as a minor pest of cowpea (Vigna unguiculata L. Walp) causes nowadays significant damages to this crop. In a perspective control of Ootheca mutabilis population, a monitoring of its population was conducted during two periods of time(from May 2014 to February 2015 and from May 2015 to February 2016) in Adzopé, south of Côte d’Ivoire. The catches were made twice a week to different phenological stages in traps made of yellow plates placed on racks placed at plant’s height. The observations revealed the presence of adults of O. mutabilis crops grown during the different seasons of the two periods. Every season, the mean number of insects per subplot registered at the stage before flowering was higher than that of flowering. The mean number of insects harvested at fruiting stage was the lowest. During the cycle of cowpea, the highest mean numbers varying from 8.33±0.33 to 41.67±2.33 were observed at the end of the stage before flowering (41 days after sowing) or at the beginning of fruiting stage (45 days after sowing). The months of June and October that correspond to periods of heavy rainfall (rainy seasons) have recorded the highest mean numbers (31.26±1.09 to 38.33±2.92 adults per subplot). The lowest mean numbers were recorded in the dry season.