DOI: 10.36347/sajb.2015.v03i07.001

Pages: 583-588

Bruchidius atrolineatus Pic. (Coleoptera-Bruchinae) is a major pest of cowpea in the Sahel. The attacks began in the fields and continue in the stocks. In this work, a morphometric study to characterize populations of this species from different cowpea varieties is performed. Individual’s male from seeds and pods of three varieties of cowpea (TN5/78 HTR and a local variety) were compared using a discriminant analysis (FDA) on 17 morphological variables. The average size of each variety was measured. The data analysis shows that these groups differ from one another primarily by size. Their decreasing rank order size is: local variety, TN5 / 78 and HTR. The individuals from HTR are clearly distinguishable from all others by the length of the first abdominal sternum (Los) longer. The maximum length of the antenna (Lan), the largest dimension of the femur 3 (Lf3), the largest dimension of the tibia 3 (Lt3), the largest radial dimension of the cell of posterior flange (Loc), and length of the pygidium (LPY) lead to distinguish individuals of the local variety. Other variables allow differentiating individuals from TN5 / 78. This is the maximum length of the head (Lmt), the length and width of pronotum (Lop and Lap), the maximum width of the elytron (Lae), the maximum radial width of the cell (Lac ), the largest dimension of the coxa 3 (CML), the maximum width of the first abdominal sternum (Las) and the width of pygidium (Lpy). The analysis of raw data by a reference variable (maximum width of pygidium, LPY) data, AFD reveals differences in form between individuals of different populations. Four variables explain the differentiation observed after data analysis. These are Lmt, Lap, Lf3 and LPY. Thus, this study shows that morphometric characters of B. atrolineatus vary depending on the variety which individuals belong. However, a genetic study seems necessary to clarify the characteristics of these different populations.