Insecticidal Activity of Four Essential Oils Extracted from Chilean Patagonian Plants as Potential Organic Pesticides

Abstract

Patagonia is a geographical area characterized by a wide plant biodiversity. Several native plant species are traditionally used in medicine by the local population and demonstrated to be sources of biologically active compounds. Due to the massive need for green and sustainable pesticides, this study was conducted to evaluate the insecticidal activity of essential oils (EOs) from understudied plants growing in this propitious area. Ciprés (Pilgerodendron uviferum), tepa (Laureliopsis philippiana), canelo (Drimys winteri), and paramela (Adesmia boronioides) EOs were extracted through steam distillation, and their compositions were analyzed through GC–MS analysis. EO contact toxicity against Musca domestica L., Spodoptera littoralis (Boisd.), and Culex quinquefasciatus Say was then evaluated. As a general trend, EOs performed better on housefly males over females. Ciprés EO showed the highest insecticidal efficacy. The LD50(90) values were 68.6 (183.7) and 11.3 (75.1) µg adult−1 on housefly females and males, respectively. All EOs were effective against S. littoralis larvae; LD50 values were 33.2–66.7 µg larva−1, and tepa EO was the most effective in terms of LD90 (i.e., <100 µg larva−1). Canelo, tepa, and paramela EOs were highly effective on C. quinquefasciatus larvae, with LC50 values < 100 µL L−1. Again, tepa EO achieved LD90 < 100 µL L−1. This EO was characterized by safrole (43.1%), linalool (27.9%), and methyl eugenol (6.9%) as major constituents. Overall, Patagonian native plant EOs can represent a valid resource for local stakeholders, to develop effective insecticides for pest and vector management, pending a proper focus on their formulation and nontarget effects.

The Essential Oil from the Resurrection Plant Myrothamnus moschatus Is Effective against Arthropods of Agricultural and Medical Interest

“…For the above reason, there has been a growing global interest in eco-friendly pesticides, including those produced by plants [5][6][7]. Among botanical products, essential oils (EOs) could play a fundamental role in the agrochemical industries, and they have been widely studied against many arthropod pests [8][9][10][11]. EOs showed different modes of action, such as antifeedant, repellent, or deterrent activities, and they can be useful as larvicide, ovicide, and adulticidal agents.…”

Encapsulation of Fennel and Basil Essential Oils in β-Cyclodextrin for Novel Biopesticide Formulation

“…These metabolites, accumulated in different parts of the plant, are components of plant extracts or essential oils (EOs) and frequently manifest toxicity, act as antifeedants through pest metabolism alternation and fitness reduction, or simply deter or repel insect pests [ 10 , 11 , 12 ]. EOs, as complex mixtures of volatile compounds, have been shown to display insecticidal properties against various pests [ 13 , 14 , 15 ]. They are already recognized as potential biopesticides involved in sustainable agriculture [ 16 , 17 , 18 , 19 , 20 , 21 , 22 ], but with challenging requirements to adapt results from laboratories to fluctuating outdoor conditions.…”

Efficacy of Mentha aquatica L. Essential Oil (Linalool/Linalool Acetate Chemotype) against Insect Vectors and Agricultural Pests

“…Among botanical products, EOs could be potential candidates for the development of novel biopesticides and insecticides. In previous studies, we showed that numerous EOs could display their insecticidal and pesticidal potential towards different insect species depending on the synergistic or antagonistic effect of their components that revealed suitable LC 50 and LC 90 values [25][26][27].…”