Storage Insects on Yam Chips and Their Traditional Management in Northern Benin

Abstract

Twenty-five villages of Northern Benin were surveyed to identify the constraints of yam chips production, assess the diversity of storage insects on yam chips, and document farmers' perception of their impacts on the stocks and their traditional management practices. Damages due to storage insects (63.9% of responses) and insufficiency of insect-resistant varieties (16.7% of responses) were the major constraints of yam chips production. Twelve insect pest species were identified among which Dinoderus porcellus Lesne (Coleoptera, Bostrichidae) was by far the most important and the most distributed (97.44% of the samples). Three predators (Teretrius nigrescens Lewis, Xylocoris flavipes Reuter, and Alloeocranum biannulipes Montrouzier & Signoret) and one parasitoid (Dinarmus basalis Rondani) all Coleoptera, Bostrichidae were also identified. The most important traditional practices used to control or prevent insect attack in yam chips were documented and the producers' preference criteria for yam cultivars used to produce chips were identified and prioritized. To further promote the production of yam chips, diversification of insect-resistant yam varieties, conception, and use of health-protective natural insecticides and popularization of modern storage structures were proposed.

Repellent Effect and Insecticidal Activities ofBridelia ferruginea,Blighia sapida, andKhaya senegalensisLeaves Powders and Extracts againstDinoderus porcellusin Infested Dried Yam Chips

“…Each plant powder was evaluated at four rates (2,5,7, and 10% w/w) and commercial synthetic insecticide Antouka (Permethrin 3 g/kg + pirimiphos 16 g/kg; DP) included as a positive control. Treated and untreated yam chips (10 g) were alternately placed equidistantly from the center of the circular base [20].…”

“…is an important crop contributing to food security and poverty alleviation in sub-Sahara region, especially in West Africa [1]. In Benin, dehydrated yam chips are the only form in which fresh yam tubers are preserved throughout the year [2]. "Télibo" or "Amala," the traditional thick paste obtained from yam chips flour, is the staple food of many people in Benin [3].…”

“…Unfortunately, dried yam chips in traditional storage systems are severely attacked by the beetle Dinoderus porcellus Lesne (Coleoptera: Bostrichidae) which rapidly reduces yam chips into powder within few days of storage [3,4]. This pest causes heavy qualitative and quantitative losses during storage [2,4,5]. Synthetic insecticides are currently used by farmers to control this pest [2], leading to many cases of food poisoning [6,7].…”

“…This pest causes heavy qualitative and quantitative losses during storage [2,4,5]. Synthetic insecticides are currently used by farmers to control this pest [2], leading to many cases of food poisoning [6,7]. The use of these insecticides also leads to a number of problems, such as danger of pesticide misuse, killing of nontarget species, toxicity residues in food, insect resistance, and the destruction of the balance of the ecosystem [8].…”

“…In addition, these indigenous plants, which are used as crude materials to control insect pest infestations, are harvested locally, are cheap, and require only limited processing [11]. In Benin, several medicinal plants such as Bridelia ferruginea, Blighia sapida, and Khaya senegalensis are used by women to control the dried yam beetle D. porcellus [2]. In fact, the antifungal [12], antibacterial [13], and insect antifeedant [14] properties of leaf extract of K. senegalensis have been demonstrated.…”