[ Effets de la pré-exposition au soleil et du pré-traitement au froid sur les différents stades de développement de Callosobruchus Maculatus (Coleoptera-Chrysomelidae) ]
Mahamadou Amadou Nafissatou1, Toufique MARIAMA2, Chaibou Rabi3, and Ali Doumma4
1 Université Abdou Moumouni de Niamey, faculté de Sciences et Techniques, Département de biologie, BP 10662, Niamey, Niger
2 Département de la Biologie, Faculté des Sciences et Techniques de l’Université Abdou Moumouni de Niamey, BP 10662 Niamey, Niger
3 Département de la Biologie, Faculté des Sciences et Techniques de l’Université Abdou Moumouni de Niamey, BP 10662 Niamey, Niger
4 Université Abdou Moumouni de Niamey, faculté de Sciences et Techniques, Département de biologie, BP 10662, Niamey, Niger
Original language: French
Copyright © 2025 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Cowpea, Vigna unguiculata (L.) Walp. (Fabaceae) is a legume that plays an important role in the dietary balance of tropical populations. These seeds are an important source of protein that can make up for the lack of animal protein in food rations in sub-Saharan countries. The Bruchidae family (Bruchidius atrolineatus, and Callosobruchus maculatus) occupies first place in the diversity of insects that have adapted to cowpea stocks. Bruchidius adults colonize cowpea crops from the start of flowering. Females lay eggs on the pods as soon as they begin to form. Larvae and pupae are therefore already present in the harvested products, which are stored in granaries. The larvae penetrate the seeds, at the expense of which they carry out their embryonic post-development. The damage caused by this insect pest can be considerable if no protective measures are taken. To prevent damage caused by C. maculatus during cowpea storage, farmers generally expose seeds and pods to sunlight for several days before storing them. The aim of this work was to study the impact of sun pre-exposure and cold pre-treatment on the different development stages of C. maculatus. The results obtained show that C. maculatus adults are more sensitive to solar radiation than to cold conservation; in the case of pre-exposure to the sun, a 100% mortality rate is observed from 1 h onwards, whereas the same result is obtained at 2h30 min in the case of cold pre-treatment. On the other hand, cold had a greater effect on eggs, L2 larvae and L4 larvae than sunlight. For eggs, a 30 minutes cold pre-treatment gives a 100% mortality rate, whereas pre-exposure to the sun requires 45 minutes. L2 larvae and L4 larvae gave respectively 100% mortality from 2h and 2h30mn cold; while for sun pre-exposure respective durations of 2h30 min and 3h were recorded.
Author Keywords: impact, cold, development, C. maculatus, Niger.
Mahamadou Amadou Nafissatou1, Toufique MARIAMA2, Chaibou Rabi3, and Ali Doumma4
1 Université Abdou Moumouni de Niamey, faculté de Sciences et Techniques, Département de biologie, BP 10662, Niamey, Niger
2 Département de la Biologie, Faculté des Sciences et Techniques de l’Université Abdou Moumouni de Niamey, BP 10662 Niamey, Niger
3 Département de la Biologie, Faculté des Sciences et Techniques de l’Université Abdou Moumouni de Niamey, BP 10662 Niamey, Niger
4 Université Abdou Moumouni de Niamey, faculté de Sciences et Techniques, Département de biologie, BP 10662, Niamey, Niger
Original language: French
Copyright © 2025 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Cowpea, Vigna unguiculata (L.) Walp. (Fabaceae) is a legume that plays an important role in the dietary balance of tropical populations. These seeds are an important source of protein that can make up for the lack of animal protein in food rations in sub-Saharan countries. The Bruchidae family (Bruchidius atrolineatus, and Callosobruchus maculatus) occupies first place in the diversity of insects that have adapted to cowpea stocks. Bruchidius adults colonize cowpea crops from the start of flowering. Females lay eggs on the pods as soon as they begin to form. Larvae and pupae are therefore already present in the harvested products, which are stored in granaries. The larvae penetrate the seeds, at the expense of which they carry out their embryonic post-development. The damage caused by this insect pest can be considerable if no protective measures are taken. To prevent damage caused by C. maculatus during cowpea storage, farmers generally expose seeds and pods to sunlight for several days before storing them. The aim of this work was to study the impact of sun pre-exposure and cold pre-treatment on the different development stages of C. maculatus. The results obtained show that C. maculatus adults are more sensitive to solar radiation than to cold conservation; in the case of pre-exposure to the sun, a 100% mortality rate is observed from 1 h onwards, whereas the same result is obtained at 2h30 min in the case of cold pre-treatment. On the other hand, cold had a greater effect on eggs, L2 larvae and L4 larvae than sunlight. For eggs, a 30 minutes cold pre-treatment gives a 100% mortality rate, whereas pre-exposure to the sun requires 45 minutes. L2 larvae and L4 larvae gave respectively 100% mortality from 2h and 2h30mn cold; while for sun pre-exposure respective durations of 2h30 min and 3h were recorded.
Author Keywords: impact, cold, development, C. maculatus, Niger.
Abstract: (french)
Le niébé, Vigna unguiculata (L.) Walp. (Fabaceae) est une légumineuse qui joue un rôle important dans l’équilibre alimentaire des populations des régions tropicales. Ces graines constituent une importante source de protéines pouvant combler les insuffisances en protéines animales des rations alimentaires dans les pays subsahariens. La famille des Bruchidae (Bruchidius atrolineatus, et Callosobruchus maculatus) occupe la première place de la diversité des insectes qui se sont adaptés aux stocks de niébé. Les adultes de bruches colonisent les cultures de niébé dès le début de la floraison. Les femelles pondent sur les gousses dès que celles-ci commencent à se former. Les larves et les nymphes sont donc déjà présentes dans les produits de la récolte qui seront entreposés dans les greniers. Les larves pénètrent dans les graines aux dépens desquelles elles assurent leur développement poste embryonnaire. Le dommage causé par cet insecte nuisible peut être important si aucune mesure de protection n’est prise. Afin de prévenir les dommages causés par C. maculatus lors du stockage du niébé, les agriculteurs exposent généralement les graines et les gousses aux radiations du soleil pendant plusieurs jours avant de les stocker. L’objectif de ce travail est d’étudier l’impact de la pré-exposition au soleil et du prétraitement au froid sur les différents stades de développement de C. maculatus. Les résultats obtenus montrent que, les adultes de C. maculatus sont plus sensibles aux radiations solaires qu’à la conservation au froid; au niveau de la pré-exposition au soleil un taux de mortalité de 100% est observé à partir de 1h; alors que ce même résultat est obtenu à 2h30mn au niveau du prétraitement au froid. Par contre le froid agit plus sur: les œufs; les larves L2 et les larves L4 que le soleil. En effet pour les œufs un prétraitement au froid de 30mn donne un taux de mortalité de 100% alors que pour la pré-exposition au soleil il faut une durée de 45mn. Les larves L2 et les larves L4 donnent respectivement 100% de mortalité à partir de 2h et 2h30mn au froid; tandis que pour la pré-exposition au soleil les durées respectives de 2h30 mn et 3h sont enregistrées.
Author Keywords: impact, froid, soleil, développements, C. maculatus, Niger.
