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This paper reports the presence and characteristics of the bruchid Spermophagus niger Motschulsky as a major pest of roselle (Hibiscus sabdariffa L.) seeds during post-harvest storage in Burkina Faso. Samples of roselle seeds collected in farmers granaries at three locations in Burkina Faso at the beginning of crop storage were brought to the laboratory and held for 2 months. All seed samples were infested with varying levels of S. niger, though samples from Tougan and Dedougou were more highly infested than those from Ouagadougou. Infested seeds generally had only one insect emergence hole, with seed perforation rates ranging from 1.8% to 4%. Insect rearing in the laboratory provided an opportunity for a clearer discrimination of sexual dimorphism and a better morphological description of the species. Males were smaller and weighed less than females. Post-embryonic development, which took place entirely within the seed, included four larval instars and one pupal stage; these stages are common in the subfamily Bruchinae. Our preliminary observations will enable a better understanding of this previously little-known insect pest. Furthermore, these results offer baseline data for further into appropriate postharvest management of roselle in West Africa.

Tetranychus evansi is an invasive pest of Solanaceae in West Africa. It causes severe damage and economic losses in tomato production. This study, conducted in four sites (Loumbila, Ouagadougou, Pabré and Tanghin-Dassouri) in the central zone of Burkina Faso, assessed the density of T. evansi over two growing seasons and evaluated the infestation levels through the tomato growth cycle from planting up to harvest. Mite’s population was assessed weekly from March to May during the dry season and from August to October for the rainy season in Burkina Faso. We found a high density of T. evansi during the hot and dry periods corresponding to increase temperatures. The Loumbila, Pabré, and Tanghin-Dassouri sites show a similar density of the mite’s population and generally have an average of fewer than 20 individuals per leaf compared to the site in Ouagadougou with a density of more than 80 individuals per leaf. In contrast, during the rainy season, which is characterized by high humidity, densities of T. evansi were as low as 10 individuals per leaf. We also found that, when climatic and environmental conditions are favorable, all growth stages of the tomato are attacked by the pest. As producers face many difficulties to control T. evansi, there is an urgent need to implement an integrated pest management strategy against this pest.