Fumigant Toxicity in Myzus persicae Sulzer (Hemiptera: Aphididae): Controlled Release of (E)-anethole from Microspheres

Abstract

(E)-anethole is a phenylpropanoid that is the main compound found in the essential oils (EOs) of anise and fennel seeds, and either fumigant or direct contact activity of this compound has been demonstrated against aphids and stored product pests. In this work, solid microspheres were prepared by three methods—oil emulsion entrapment, spray-drying, and complexed with β-cyclodextrin. Fumigation activity of each microsphere preparation was tested against the green peach aphid, Myzus persicae Sulzer (Hemiptera: Aphididae), on pepper leaves. The best insecticidal activity was with (E)-anethole encapsulated in oil emulsion beads and introduced to aphids as a vapour over 24 h, with an LC50 of 0.415 μL/L compared to 0.336 μL/L of vapors from free (E)-anethole. Scanning electron microscopy of the beads revealed a compact surface with low porosity that produced a controlled release of the bioactive for more than 21 d, whilst most of the volatile was evaporated within two days if applied unformulated. Spray drying gave spherical particles with the greatest encapsulated yield (73%) of 6.15 g of (E)-anethole incorporated per 100 g of powder. Further work will be done on improving the formulation methods and testing the solid microspheres in all aphid stages scaling up the experimental assay. It is foreseen that nanotechnology will play a role in future developments of low risk plant protection products.

Aphicidal activity of farnesol against the green peach aphid – Myzus persicae

“…In previous works, we studied the repellent and/or insecticidal effects of different EOs and pure compounds on various aphid species: Rhopalosiphum padi (L.), Nasonovia ribisnigri (Mosley), Macrosiphum euphorbiae (Thomas) and M. persicae. [15][16][17][18][19] The results of these works show different responses in some cases (repellent and/or aphicidal effect) among these aphid species for the same product.…”

New Insights Into Biopesticides: Solid and Liquid Formulations of Essential Oils and Derivatives

“…However, the use of these solid encapsulants is not limited to warehouse or stored pests. Their effectiveness in insects such as Myzus persicae Sulzer (Hemiptera: Aphididae) has also been demonstrated in a recent study that evaluated three encapsulation methods: oil emulsion entrapment, spray-drying, and the encapsulation of (E)-anethole monoterpene in βcyclodextrins (Pascual-Villalobos et al, 2020). It was concluded that most of the free (E)-anethole vapors were available within 2 days of application, whereas the preparations prolonged the release period for several weeks and required at least a week to release 20% of the bioactive compounds, depending on the temperature and formulation.…”

Effects of Hibiscus Rosa Sinensis and Cymbopogon Citratus Against Aphids : A Review

“…Heat increases the toxicity of Tribolium castaneum was also detected. Good pesticidal effect on trichoplusia ni huber of lemongrass or thyme essential oils or double combination of two compounds have good activity in the green house (Villalobos et al, 2020).…”