Potential of Botanicals to Control Callosobruchus maculatus (Col.: Chrysomelidae, Bruchinae), a Major Pest of Stored Cowpeas in Burkina Faso: A Review

Abstract

Cowpea is an essential food legume in the tropics and particularly for sub-Saharan African populations. Postharvest grain storage, however, is a major constraint for crop expansion and year-round availability due to the cowpea weevil, Callosobruchus maculatus F., the main storage pest of cowpeas in West Africa. The use of chemicals for cowpea storage is a common practice which represents, however, a risk for consumers, environment, and could also exacerbate pest control. In Burkina Faso, since the early 2000s, several scientific investigations have focused on the control of C maculatus using botanicals considered as promising and safe alternatives to chemicals. The aim of this review is to take stock of the research conducted and to identify the potential candidates on which future studies in this field will focus. The set of data analyzed show that several plants materials, including powders, crushed plants and essential oils (EO), were active against eggs, larvae, and adults of C maculatus, through dose-dependent mortality responses. However, EO extracted from native aromatic plants have yielded the most promising results, specifically EO from Ocimum canum appeared as the best candidate control agent. Other potentially interested EO tested included Hyptis suaveolens, Hyptis spicigera, and Lippia multiflora. Based on these results, attempts to optimize the use of EO for cowpea storage were conducted in laboratory and field conditions. Side effects of botanicals toward the main biological control agent, the ectoparasitoid Dinarmus basalis have also been highlighted. The results are discussed in a view of practical use of botanicals and EO as safe alternatives for Integrated Pest Management in stored cowpeas in Africa and developing countries.

Application of multi‐locus GWAS for the detection of bruchid resistance loci in cowpea (Vigna unguiculata)

“…However, the chemical products commonly used to protect cowpea seeds under postharvest conditions pose a risk to human and environmental health and could also lead to the development of chemical resistance in pests (Kpoviessi et al, 2019; Sanon et al, 2018). Botanical plants have also been considered as promising, environmentally friendly and safe alternatives to chemicals used in stored cowpea (Kpoviessi et al, 2019; Sanon et al, 2018). However, these pesticides are not 100% safe and labour intensive and therefore unsatisfactory for resource constrained farmers (Isra et al, 2016).…”

Efficacy of Ocimum tenuiflorum essential oil as grain protectant against coleopteran beetle, infesting stored pulses

“…Promising control of Callosobruchus species has been reported by the application of EO and their components (monoterpenoids, cyanohydrins, sulphur compounds, thiocyanates) as fumigants (Kedia et al 2015;Sanon et al 2018). Though there are a few reports on insecticidal activities of Ocimum species against Callosobruchus species, comprehensive assessment on the efficacy of Ocimum tenuiflorum EO as a biopesticide in stored pulses has not been studied.…”

Expression of the Arcelin 1 gene from Phaseolus vulgaris L. in cowpea seeds (Vigna unguiculata L.) confers bruchid resistance

“…Although Z. subfasciatus attacks both common bean and cowpea, Callosobruchus maculatus colonises only cowpea (Silva et al, ; Sanon et al, ), especially in storage (Cope & Fox, ). Genetic resistance against bruchids is in Phaseolus vulgaris and is associated with seed proteins family of alpha amylase inhibitor, phytohemagglutinin and lectin‐like proteins (APL) called arcelin (Arc) (Lioi et al, ; Bifano et al, ; Zaugg et al, ).…”