First Assessment of the Reproductive Potential of Spermophagus niger (Motschulsky, 1866) (Coleoptera: Chrysomelidae) on Hibiscus asper Hook. f. (Malvales: Malvaceae) Seeds

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Résumé

Spermophagus niger L. (Coleoptera: Chrysomelidae) is the main insect pest of Hibiscus sabdariffa seeds (Malvales: Malvaceae) during storage, with initial infestations occurring in the field. This study presents the first assessment of S. niger development on Hibiscus asper seeds (Malvales: Malvaceae), a wild and underutilized species widely distributed across tropical Africa and Madagascar. The aim was to evaluate its potential role in the ecological management of H. sabdariffa seed infestations. Twenty pairs of less than 24 h-old S. niger adults were individually placed in Petri dishes (9 cm diameter × 1.5 cm height), each in contact with 30 healthy H. asper seeds, under controlled conditions (32°C ± 0.1; 43 ± 1% r.h.) in total darkness. The seeds were renewed daily until the insects died. The results showed that S. niger completes its developmental cycle on H. asper seeds. However, its reproductive success was significantly lower than that of the H. sabdariffa varieties. This study suggests that H. asper could play a strategic role in reducing initial infestation pressure and could be incorporated into sustainable pest management strategies for H. sabdariffa cultivation

Mots-clés

development, ecological management, Hibiscus asper, Hibiscus sabdarifa, Spermophagus niger