Loko et al. The Journal of Basic and Applied Zoology (2019) 80:41 The Journal of Basic https://doi.org/10.1186/s41936-019-0113-3 and Applied Zoology RESEARCH Open Access Farmers knowledge, perceptions and management of Kersting’s groundnut (Macrotyloma geocarpum Harms) insect pests in Benin Yêyinou Laura Estelle Loko1* , Jerôme Akohonwe1, Joelle Toffa1, Azize Orobiyi1, Prisca Assogba2, Alexandre Dansi2 and Manuele Tamò3 Abstract Background: Macrotyloma geocarpum Harms is a neglected and underutilized crop in Benin subject to several constraints including storage insect attacks, which contribute to the decrease in its production. An ethnobotanical survey using a semi-structured questionnaire was conducted in 15 villages in southern and central Benin to document farmers’ perceptions of M. geocarpum storage insect pests and their traditional management practices. Results: The results showed that insect pest were the most important storage constraint of M. geocarpum.To overcome this constraint, the promotion of resistant landraces has been proposed by farmers. Six vernaculars names of storage insect pests of M. geocarpum were identified throughout the study area and all corresponding to Callosobruchus maculatus (F.) which proved to be the most abundant insect in the stocks. Palatability and fragility of seeds coat have been identified by farmers as the main factors favoring the infestation by this pest. Various storage containers of M. geocarpum have been inventoried. Our study revealed that education, storage containers, and Kersting’s groundnut landraces significantly influenced farmers’ perceptions of severity of insect pest damages. The use of chemicals and repellent plants were the main control methods used by farmers to protect stocks. Different levels of resistance of M. geocarpum landraces to storage insect pests were reported. Conclusions: This study provides baseline information for development of integrated management approaches against storage insect pests of M. geocarpum. The perceived level of resistance to insect damage on Kersting’s groundnut landraces needs to be investigated. Keywords: Kersting’s groundnut, Management practices, Storage constraints, Insect pests, Varietal resistance Background Benin, the seeds of M. geocarpum are particularly pre- Macrotyloma geocarpum (Harms), or Kersting’s ground- ferred over other grain legumes because of their high nut, is an important African indigenous legume crop of palatability (Achigan-Dako & Vodouhè, 2006; Assogba the Fabaceae family grown on a small scale in West et al., 2015). Its edible seeds are high in proteins, carbo- Africa for its grains are produced in pods developing hydrates, and essential amino acids (Chickwendu, 2007). below ground (Pasquet, Mergeai, & Baudoin, 2002). They are also a good source of minerals such as phos- Identified as a neglected and underutilized species in phorus, potassium, calcium, and sodium (Oyetayo & Benin (Dansi et al., 2012), Kersting’s groundnut is native Ajayi, 2005). According to Ajayi and Oyetayo (2009), to and mainly grown in West Africa (Hepper, 1963). In Kersting’s groundnut can be used in the formulation of dietary supplements for children and thus help to com- * Correspondence: [email protected] bat malnutrition. Moreover, it is an important source of 1Laboratory of Applied Entomology, Faculty of Sciences and Technology of Dassa (FAST-Dassa), National University of Sciences Technologies Engineering income (2 to 6 USD per kilogram) for the rural popula- and Mathematics of Abomey (UNSTIM), BP 14, Dassa, Benin tion of Benin (Assogba et al., 2015). Full list of author information is available at the end of the article © The Author(s). 2019 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Loko et al. The Journal of Basic and Applied Zoology (2019) 80:41 Page 2 of 11 Unfortunately, M. geocarpum is on the verge to be ethnic groups are Adja, Cotafon, Holly, Ouéménou, abandoned in several countries including Benin Pédah, Saxwé, Tori, Watchi, Xwla, Yoruba, Fon, Mahi, (Assogba et al., 2015), mainly because of its poor storage Idaasha, Fé, and Tchabé (Adam & Boko, 1993). Ethno- capacity of seeds (Kouelo et al., 2012). In fact, a major botanical survey was conducted in 15 villages selected in constraint faced by farmers in post-harvest is pest attack southern and central Benin (Fig. 1) based on the litera- during storage (Assogba et al., 2015; Ayenan & Ezin, ture review, their accessibility and discussions with 2016). However, very little attention has been given to farmers and extension agricultural services locally the constraints related to the storage of M. geocarpum named CARDER (regional action centres for rural devel- seeds in Benin. Although Achigan-Dako and Vodouhè opment). (2006) notified that stored seeds are very susceptible to weevils and bruchids infestations, the diversity of insect Data collection pest species associated to stored seeds of M. geocarpum A survey was implemented to collect data using partici- in the production areas is still unknown, and the percep- patory research appraisal tools and techniques, such as tion of farmers about the extent of damage caused by direct observation, individual interviews, and field visits, these pests has never been evaluated. In addition, trad- using a pre-established questionnaire following Orobiyi itional management practices used to prevent or control et al. (2013). The surveyed farmers in each village were insect infestations have been very scarce, whereas this selected with the assistance of the chiefs of the village knowledge is needed for the development of effective in- but also by the “snowball” sampling method. This is a tegrated pest management approaches adapted to the chain-sampling method that relies on the recommenda- needs of local farmers (Norton, Rajotte, & Gapud, 1999; tions of the starting subjects to reach additional partici- Van Huis & Meerman, 1997). In this context, farmers’ pants (Johnston & Sabin, 2010). A total of 83 producers perceptions of storage insect pest management are key of M. geocarpum were surveyed throughout the study elements for the design of efficient and easily implemen- area. The data collected focused on the socio- table control practices (Okonya, Mwanga, Syndikus, & demographic characteristics of the interviewees (sex, Kroschel, 2014). age, education, years of experience in the cultivation of The resistant varieties are a most economical and Kersting’s groundnut, area sown), the constraints related healthy way to minimize loss due to attack of storage in- to the storage of Kersting’s groundnut seeds, the periods sects (Badii, Asante, & Bayorbor, 2011). However, in of infestation, farmers perception of insect pests of Benin, resistance of Kersting’s groundnut landraces to stored Kersting’s groundnut seeds, storage containers, storage insects and the reasons of the observed suscepti- shelf life, severity of insect pest attack, susceptibility, and bility have never been investigated. We report in this resistance of Kersting’s groundnut landraces to storage paper the findings of a study carried out in Benin in insects and management practices of insects in Ker- order to (1) identify Kersting’s groundnut storage con- sting’s groundnut stocks. The perception on the storage straints and solutions proposed by farmers to overcome insect severity was captured as a categorical variable these constraints, (2) evaluate farmers’ knowledge and using a 4-point Likert scale rating (Khan et al., 2014). perceptions of its storage pests, (3) examine farmers’ Farmers were asked to score for the level of damage current practices in managing its storage pests, and (4) caused by insect pests (Munyuli et al., 2017). A four- identify landraces that have some resistance to damage point scale (0 = no severe, 1 = moderate severity, 2 = se- by storage insect pests. vere, and 3 = very severe) was used for rating the dam- age level perceived. Insects identified by farmers as Methods storage pests of M. geocarpum were collected and stored Study area in labelled boxes (village, storage container, vernacular The present study was conducted in southern and cen- name) containing alcohol at 70 °C, for later identification tral Benin which are the major production area of M. in the laboratory. Similarly, plant samples used by geocarpum (Assogba et al., 2015, Kouelo et al., 2012, farmers to control storage insects were collected and Worou, Zandjanakou-Tachin, Boulga, & Bokonon- tagged (vernacular name of the plant, village name, and Ganta, 2016). The south and the centre are relatively method of use) and returned to the laboratory for humid agro-ecological zones with bimodal rainy seasons identification. and mean annual rainfall varying from 1.100 to 1.400 mm/year (Yabi & Afouda, 2012). Mean annual tempera- Inventory of insect fauna associated to stored seeds of tures range from 26 to 28 °C (Adam & Boko, 1993). Kersting’s groundnut Vegetation types are semi-deciduous forest (south), In each prospected village, 300 g of infested Kersting’s woodland and savannah (center east), and dry semi- groundnut seeds was weighed using an electronic scale deciduous forest (center west and south). The main and collected from