Assessment of Chemical and Nutritional Composition of Seeds Attacked by Prosoestus spp (Coleoptera: Curculionidae), Major Pests of Female Inflorescences of Oil Palm (Elaeis guineensis Jacq.)

Abstract

Oil Palm (Elaeis guineensis) has social, economic, and cultural importance in Côte d'Ivoire. From its roots to its leaves, and at every stage of its growth, it is exposed to many pests, the most important of which, affecting the female inflorescences, are Prosoestus minor and Prosoestus sculptilis (Coleoptera: Curculionidae). This study was conducted at the National Center for Agronomic Research, station in La Mé. The aim was to assess, on the one hand, the extent of damage caused by these two pests to female inflorescences and, on the other hand, the chemical and nutritional components of the seeds obtained from their attacks. Two hundred (200) individuals of each species were captured and placed on female inflorescences at the beginning of anthesis, enclosed in muslin cages. Monitoring the bunches until maturity revealed that Prosoestus sculptilis causes more damage (71.51 ± 11.42%) to the bunches than P. minor (60.96 ± 16.93%). The oil content per fruit (THR) was lower in attacked seeds (P. minor = 18.49 ± 4.67%; P. sculptilis = 15.33 ± 6.14%) than in control seeds (42.19 ± 9.12%). In addition, the acidity and fluidity of the oil were more degraded because they were very high (7.68 ± 9.10; 161.11 ± 83.82) due to attacks by Prosoestus sculptilis. The concentration of most fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, and vitamins A and E contained in the oil from seeds attacked by these pests, does not comply with Codex Alimentarius standards, as it leads to a significant decrease in the physicochemical and nutritional quality of palm oil. Consequently, for sustainable food security, female inflorescences of oil palms must be effectively protected against attacks by these pests.