Evaluation of the insecticidal activity of Moringa oleifera seed extract and lectin (WSMoL) against Sitophilus zeamais. (May 2020)

• Record Type: Journal Article
• Authors: de Oliveira, Ana Patrícia Silva; Agra-Neto, Afonso Cordeiro; Pontual, Emmanuel Viana; Lima, Thâmarah de Albuquerque; Cruz, Kamila Cardoso Vera; de Melo, Karolynne Rodrigues; de Oliveira, Amanda Samson; Coelho, Luana Cassandra Breitenbach Barroso; Ferreira, Magda Rhayanny Assunção; Soares, Luiz Alberto Lira; Napoleão, Thiago Henrique; Paiva, Patrícia Maria Guedes
• Is Part Of: Journal of stored products research. Volume 87(2020)
• Publication Date: 2020-05
• Subjects: Moringa oleifera -- Maize weevil -- Antinutritional effect -- Digestive enzymes -- Lectin; Food -- Storage -- Periodicals; Farm produce -- Storage -- Diseases and injuries -- Periodicals; Entomology -- Periodicals; Food Contamination -- Periodicals; Food Preservation -- Periodicals; Insect Control -- Periodicals; Aliments -- Entreposage -- Périodiques; Produits agricoles -- Entreposage -- Maladies et dommages -- Périodiques; Electronic journals; 631.568
• DOI: 10.1016/j.jspr.2020.101615
• Languages: English
• ISSNs: 0022-474X

Abstract

Abstract: The maize weevil Sitophilus zeamais is a pest of remarkable economic importance as it attacks stored grains, processed cereals, and industrial foods. In this study, a water extract (WE) from Moringa oleifera seeds and water-soluble lectin (WSMoL) isolated from it were investigated for insecticidal activity against S. zeamais adults. The insects were maintained for 10 days on plates containing an artificial diet composed of wheat flour supplemented with WE (60.0–640.0 mg/g) or WSMoL (0.5–60 mg/g). Mortality rate, insect biomass, and amount of food consumed were recorded. The effects of WE and WSMoL on trypsin-like, α-amylase, and endoglucanase activities from insect guts were also investigated. Phytochemical analysis revealed the presence of flavonoids, tannins, saponins, phenylpropanoids, alkaloids, and reducing sugars in the WE. Furthermore, the presence of rutin and ellagic acid was confirmed by HPLC. The extract was toxic to S. zeamais (LC50 : 214.6 mg/g) while WSMoL caused slight mortality (12.0 ± 2.7%) at the highest tested dose (60 mg/g). The intake of WE exerted moderate to strong deterrent effects. Moreover, WSMoL decreased the relative biomass gain rate and efficiency in the conversion of ingested food but did not exert deterrent action. The WE stimulated α-amylase and endoglucanase activities, while WSMoL stimulated trypsin-like activity from S. zeamais gut. In conclusion, the WE was toxic to S. zeamais probably due to its feeding-deterrent activity, while WSMoL did not cause acute mortality but negatively affected the nutritional physiology of the insects, which can have long-term impacts. Highlights: Water extract (WE) from Moringa oleifera seeds was toxic to Sitophilus zeamais (LC50 : 214.6 mg/g). The extract contained lectin, flavonoids (rutin), tannins (ellagic acid), saponins, phenylpropanoids, alkaloids, and reducing sugars. The intake of WE exerted moderate to strong deterrent effects. The water-soluble lectin (WSMoL) from moringa seeds caused slight mortality but negatively affected the nutritional physiology of the insects.