Essential Oils from Cameroonian Aromatic Plants as Effective Insecticides against Mosquitoes, Houseflies, and Moths

Joice G Nkuimi Wandjou; Cecilia Baldassarri; Marta Ferrati; Filippo Maggi; Roman Pavela; Nole Tsabang; Riccardo Petrelli; Renato Ricciardi; Nicolas Desneux; Giovanni Benelli

doi:10.3390/plants11182353

Essential Oils from Cameroonian Aromatic Plants as Effective Insecticides against Mosquitoes, Houseflies, and Moths

Plants (Basel). 2022 Sep 9;11(18):2353. doi: 10.3390/plants11182353.

Authors

Affiliations

¹ Chemistry Interdisciplinary Project (ChIP), School of Pharmacy, University of Camerino, 62032 Camerino, Italy.
² Crop Research Institute, Drnovska 507, 161 06 Prague 6, Czech Republic.
³ Department of Plant Protection, Czech University of Life Sciences Prague, Kamycka 129, 165 00 Prague 6, Suchdol, Czech Republic.
⁴ Department of Animal Biology, University of Dschang, Dschang, Cameroon.
⁵ Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy.
⁶ Université Côte d'Azur, INRAE, CNRS, UMR ISA, 06000 Nice, France.

Abstract

Recently, spices have attracted the attention of scientists and agrochemical companies for their potential as insecticidal and acaricidal agents, and even as repellents to replace synthetic compounds that are labeled with detrimental impacts on environment and human and animal health. In this framework, the aim of this study was to evaluate the insecticidal potential of the essential oils (EOs) obtained from three Cameroonian aromatic plants, namely Monodora myristica (Gaertn.) Dunal, Xylopia aethiopica (Dunal) A. Rich., and Aframomum citratum (J. Pereira) K. Schum. They were produced by hydrodistillation, with yields of 3.84, 4.89, and 0.85%, respectively. The chemical composition was evaluated by GC-MS analysis. The EOs and their major constituents (i.e., geraniol, sabinene, α-pinene, p-cymene, α-phellandrene, and β-pinene) were tested against the polyphagous moth pest, i.e., Spodoptera littoralis (Boisd.), the common housefly, Musca domestica L., and the filariasis and arbovirus mosquito vector, Culex quinquefasciatus Say. Our results showed that M. myristica and X. aethiopica EOs were the most effective against M. domestica adults, being effective on both males (22.1 µg adult^-1) and females (LD₅₀: 29.1 µg adult^-1). The M. myristica EO and geraniol showed the highest toxicity on S. littoralis, with LD₅₀₍₉₀₎ values of 29.3 (123.5) and 25.3 (83.2) µg larva^-1, respectively. Last, the EOs from M. myristica and X. aethiopica, as well as the major constituents p-cymene and α-phellandrene, were the most toxic against C. quinquefasciatus larvae. The selected EOs may potentially lead to the production of cheap and effective botanical insecticides for African smallholders, although the development of effective formulations, a safety evaluation, and an in-depth study of their efficacy on different insect species are needed.

Keywords: Aframomum citratum; Culex quinquefasciatus; Culicidae; Monodora myristica; Musca domestica; Muscidae; Noctuidae; Spodoptera littoralis; Xylopia aethiopica; geraniol; p-cymene; sabinene; α-phellandrene; α-pinene; β-pinene.

Grants and funding

This research was funded by the Ministry of Agriculture of the Czech Republic (Project MZE-RO0418) and by the Italian Ministry of Health (PRIN 2017CBNCYT_005).