Reproductive Potential of Spermophagus niger (Coleoptera: Chrysomelidae: Bruchinae: Amblycerini) Developing on the Seeds of Two Roselle Varieties in Burkina Faso

摘要

In West Africa and particularly in Burkina Faso, Roselle, Hibiscus sabdariffa L. (Malvaceae) is receiving increasing attention as a crop with potential for making great socio-economic impacts. The biology of Spermophagus niger, recently identified as the main insect pest in the storage of roselle seeds, is poorly known. The present study aimed at comparing the reproductive potential of this insect on the seeds of two roselle varieties Altissima and Sabdariffa, mainly grown in Burkina Faso to identify susceptible/resistant variety to the pest. The results obtained are the first complete data on life history traits of S. niger in laboratory conditions. Overall, they indicated that both seed varieties have similar susceptibility to S. niger. The main life history traits measured did not differ significantly on both varieties (P style="font-family:Verdana, Helvetica, Arial;font-size:12px;line-height:18px;white-space:normal;background-color:#FFFFFF;"> 0.05). However, the first generation individuals from the Altissima seeds were significantly larger (P = 0.0007 and P style="font-family:Verdana, Helvetica, Arial;font-size:12px;line-height:18px;white-space:normal;background-color:#FFFFFF;"> 0.0001 for males and females respectively) and weighed more (P style="font-family:Verdana, Helvetica, Arial;font-size:12px;line-height:18px;white-space:normal;background-color:#FFFFFF;"> 0.0001) than those from the other roselle variety. This result suggests that individuals from the Altissima variety may have a higher seed-damaging potential than those developed in the Sabdariffa variety and this potential might increase over successive generations. The consequences of such findings are discussed with a view to improving the post-harvest storage of roselle seeds and reducing losses in West Africa.