Acaricidal activity of essential oil nanoemulsion against the African red mite (Eutetranychus africanus)

Abstract

The African red mite (Eutetranychus africanus [Tucker]) is an important pest species of some economic plants.The objective of the present study was to evaluate the effectiveness of nanoemulsions consisting of citronella grass, lemongrass, clove, and cinnamon essential oils and their main chemical compounds against the African red mite; their toxicity, egg-laying inhibition, and repellent effect on the mite were determined. Essential oil nanoemulsions (nEOs) were prepared by mixing the essential oils with different surfactants and co-surfactants. Approximately 10 to 15 female mites were transferred to treated leaves placed on soaked cotton and kept in a Petri dish. Mite mortality and number of eggs laid were checked after 24 h. As for the repellency test, the selected test consisted of dipping a half leaf into the nEOs, while the other half leaf was dipped in a control (water). The repellency rate was evaluated after 24 h. Results revealed that citronella grass nEOs exhibited a highly toxic effect on the mite and only a 0.6% concentration caused 100% mite mortality. Geraniol, one of the main chemical compounds of citronella grass, represented the highest egg-laying inhibition at a 0.2% concentration with a mean of 0.1 egg compared with 4.7 eggs in the control. Furthermore, nEOs from citronella grass at a 0.1% concentration were extremely repellent against the mite with 95% repellency after 24 h. Therefore, the citronella grass essential oil nanoemulsion is appropriate for use to effectively control the African red mite.

The essential oil ofSchinus terebinthifoliusand its nanoemulsion and isolated monoterpenes: investigation of their activity againstCulex pipienswith insights into the adverse effects on non‐target organisms

“…pipiens . These findings agree with those of many other studies in which enhanced biological, including insecticidal, activities of plant EOs were obtained when properly prepared and assayed as nanoparticles 14–16, 55, 56 . When transformed into nanoparticles, materials acquire unique physical and morphological characteristics that affect their bioactivities.…”

“…Doubtless, the subcellular size and large surface area of nanopesticides, including nanoemulsions, promote their affinity towards targeted bio‐systems, their spread, ability to permeating and uptake by bio‐membranes, hence their biological activities are enhanced 14–16 . In the literature, enhanced and promising biological, including mosquitocidal, activities were obtained when natural plant products, particularly Eos, were extracted and tested at the nanoscale against various harmful insects 14–16, 29, 55–57 . The tested EO materials significantly inhibited the AChE activity of Cx.…”

Insecticidal activities of long pepper (Piper retrofractum Vahl) fruit extracts against seed beetles (Callosobruchus maculatus Fabricius, Callosobruchus chinensis Linnaeus, and Sitophilus zeamais Motschulsky) and their effects on seed germination

“…The response of the three species of seed beetles to hexane extract obtained from long pepper fruit was evaluated for repellency and attraction activities using a similar toxicity test modified from the experimental method according to Doungnapa et al. (2021) .…”

“…(2021) . As for the percentage response in terms of the repellency and attractive test, frequencies of insects in the selected test were analyzed by the χ 2 test, report according to the method of Doungnapa et al. (2021) .…”

Novel Approaches for Inhibiting the Indoor Allergen Der f 2 Excreted from House Dust Mites by Todomatsu Oil Produced from Woodland Residues

“…As it becomes clear that plant-derived acaricides have immense potential in this area, research into them is being stepped up. Essential oils produced from natural products have long been utilized in perfumery, culinary smells, and aromatherapy because they contain insecticidal components known as monoterpenes [ 32 , 33 , 34 ]. Many essential oils with antioxidant capacity and antimicrobial activity had been found, such as extracts from Lavandula angustifolia and Cinnamomum camphora chvar.…”