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Open AccessArticle

In Vitro Termiticidal Activity of Medicinal Plant Essential Oils Against Microcerotermes crassus

by Chaiamon Chantarapitak, Jarongsak Pumnuan, Chaiwat Chanpitak and Somsak Kramchote

Insects 2025, 16(12), 1261; https://doi.org/10.3390/insects16121261 - 11 Dec 2025

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Termites are destructive structural pests causing significant economic losses worldwide. Although synthetic termiticides are effective, their extensive use raises environmental and health concerns, highlighting the need for safer, sustainable alternatives. This study evaluated the contact toxicity and repellency in a closed system of essential oils (EOs) from clove (Syzygium aromaticum), cinnamon (Cinnamomum zeylanicum), and star anise (Illicium verum) against Microcerotermes crassus workers. Chemical constituents (eugenol and anethole) were characterized by GC–MS/MS, and their activities were compared with those commercial termiticides (fipronil and cypermethrin). Clove and cinnamon oils exhibited strong toxicity, with LC₅₀ values decreasing from 208.6 to 70.6 µL/L and from 362.6 to 130.5 µL/L, respectively, over 24 h. Both achieved LT₅₀ values below 10 h at 250 µL/L and over 80% repellency at 100–500 µL/L within 3–12 h. Eugenol, the major constituent, showed comparable activity. In contrast, star anise oil, dominated by anethole, displayed weaker repellency but measurable termiticidal effects with a slower onset. These findings indicate that eugenol-rich oils may provide rapid-contact activity. In contrast, anethole-rich oils may offer slower but measurable termiticidal effects, suggesting distinct potential roles in future formulation development. The findings provide a foundation for developing nanoemulsion-based botanical termiticides with improved stability and field performance. Full article

(This article belongs to the Section Insect Pest and Vector Management)

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17 pages, 2030 KB

Open AccessEditor’s ChoiceArticle

3D-Printed Bilayer Active Film with Anise Oil Nano-Emulsion and Carbon Quantum Dots for Shelf-Life Extension of Sugar Tangerines

by Qi Tian, Chongyang Chen, Chaofan Guo, Qingbo Huang, Yongli Jiang and Junjie Yi

Horticulturae 2025, 11(9), 1061; https://doi.org/10.3390/horticulturae11091061 - 4 Sep 2025

Cited by 1 | Viewed by 1544

Abstract

This study developed a novel 3D-printed bilayer film (BF) embedded with star anise essential oil nanoemulsion (AEO-NE) and tamarind shell-derived carbon quantum dots (CQDs) for preserving sugar tangerines (Citrus reticulata Blanco). The BF comprised an outer chitosan-alginate-CQD barrier layer and an inner AEO-NE active layer, fabricated using dual-extrusion 3D printing. Results showed that BF-treated fruits had significantly lower weight loss (23.6% reduction) and decay rates (0% spoilage until day 10) compared to controls (p < 0.05). The film’s controlled release (31% AEO release over 15 days) and UV-blocking properties (CQDs) maintained fruit firmness, color stability (ΔE < 2.0), and sugar content (TSS increase of only 3.7%). Sensory evaluation confirmed BF’s superiority, with treated fruits retaining freshness for 15 days, while controls deteriorated rapidly. The study demonstrates that 3D-printed active films synergizing AEO and CQDs offer a sustainable, high-performance solution for citrus preservation, extending shelf life by 10–15 days. Full article

(This article belongs to the Special Issue Postharvest Preservation and Processing Techniques for Horticultural Products)

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12 pages, 1536 KB

Open AccessFeature PaperArticle

Contact Toxicity and Ovideterrent Activity of Three Essential Oil-Based Nano-Emulsions against the Olive Fruit Fly Bactrocera oleae

by Giulia Giunti, Francesca Laudani, Emilio Lo Presti, Monica Bacchi, Vincenzo Palmeri and Orlando Campolo

Horticulturae 2022, 8(3), 240; https://doi.org/10.3390/horticulturae8030240 - 10 Mar 2022

Cited by 25 | Viewed by 4712

Abstract

The control strategies for the olive crop key pest, Bactrocera oleae, involve synthetic chemical insecticides and few eco-sustainable alternatives, such as ovideterrents and lures. In the last few decades, the interest concerning the formulation of botanical based biopesticides increased, but little research investigated the suitability of these approaches for B. oleae control. This research aimed to investigate the residual contact toxicity and the oviposition deterrence of three essential oil (EO)-based nano-emulsions (Pimpinella anisum, Foeniculum vulgare, Mentha × piperita) against B. oleae adult flies. All the nano-emulsions possessed optimal physical characteristics, with droplets dimensions ranging from 115 to 152 nm and low PDI values (<0.2), even after 1 year of storage. Although no notable residual contact toxicity was noted, all the tested formulations reduced the number of oviposition puncture in no-choice tests (percent repellence: mint < fennel < anise). In choice trials, olives treated with fennel and anise EO-formulations at the highest concentration (7.5%, 75 g of EO/L) were less attractive respect to control fruits and a significant reduction of olive punctures was recorded. Nano-biopesticides are promising eco-friendly tools to integrate B. oleae pest management programs and to reduce the use of harmful conventional active ingredients. Full article

(This article belongs to the Special Issue New Insights into Pest Management in Horticultural Production)

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11 pages, 1146 KB

Open AccessArticle

Antimicrobial Activity of Nanoencapsulated Essential Oils of Tasmannia lanceolata, Backhousia citriodora and Syzygium anisatum against Weak-Acid Resistant Zygosaccharomyces bailii in Clear Apple Juice

by Fahad Alderees, Saleha Akter, Ram Mereddy and Yasmina Sultanbawa

Beverages 2021, 7(3), 67; https://doi.org/10.3390/beverages7030067 - 17 Sep 2021

Cited by 10 | Viewed by 6283

Abstract

The anti-yeast activity of oil-in-water encapsulated nanoemulsion containing individual or a combination of the three essential oils of Tasmanian pepper leaf (Tasmannia lanceolata), lemon myrtle (Backhousia citriodora), and anise myrtle (Syzygium anisatum) against weak-acid resistant Zygosaccharomyces bailii in clear apple juice was investigated. The effectiveness of the shelf-life extension of Z. bailii-spiked (1 × 10³ CFU/mL) clear apple juice was evaluated and compared between natural (essential oils) and synthetic (sodium benzoate) antimicrobial agents. Essential oils showed an immediate reduction in the Z. bailii cell population at day-0 and exerted a fungicidal activity at day-4 of storage, with no further noticeable growth at the end of the experiment (day-28). At lower concentrations, Tasmanian pepper leaf oil of 0.0025% had >6 log CFU/mL at day-12 of storage. For lemon myrtle essential oils, the yeast population reached >6 log CFU/mL at day-24 and day-20 for concentrations of 0.02% and 0.01%, respectively. The fungicidal activity of Tasmanian pepper leaf oil reduced from 0.005% to 0.0025% v/v when mixed at a ratio of 1:1 with anise myrtle oil. The results of the present study suggest that these three native Australian herbs have the potential to be used in the beverage industry by controlling Zygosaccharomyces bailii in clear apple juice products. Full article

(This article belongs to the Special Issue Fruit Juices: Technology, Chemistry, and Nutrition 2.0)

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13 pages, 302 KB

Open AccessArticle

Essential Oil-Based Nano-Biopesticides: Formulation and Bioactivity against the Confused Flour Beetle Tribolium confusum

by Davide Palermo, Giulia Giunti, Francesca Laudani, Vincenzo Palmeri and Orlando Campolo

Sustainability 2021, 13(17), 9746; https://doi.org/10.3390/su13179746 - 30 Aug 2021

Cited by 77 | Viewed by 7501

Abstract

Post-harvest pest control can rely on few approved pesticides and tools; hence, there is a rising interest in new sustainable, eco-friendly approaches. In this study, eight commercial essential oils (EOs) (anise Pimpinella anisum, artemisia Artemisia vulgaris, fennel Foenicum vulgare, garlic Allium sativum, lavender Lavandula angustifolia, mint Mentha piperita, rosemary Rosmarinus officinalis, and sage Salvia officinalis) were selected for their bioactivity and commercial availability, and then formulated in nano-emulsions. Repellency and acute toxicity of the developed nano-formulations were tested against a key stored product pest, Tribolium confusum (Coleoptera: Tenebrionidae). All the developed nano-emulsions presented optimal physical characteristics (droplet dimension = 95.01–144.30 nm; PDI = 0.146–0.248). All the formulations were repellent over time tested against adult beetles, in area preference bioassays. The best repellent was the anise EO-based formulation (RC₅₀ = 0.033 mg). Mortality values from cold aerosol trials showed that the majority of tested EOs caused immediate acute toxicity, and garlic EO nano-emulsion caused the highest mortality of T. confusum adults (LC₅₀ = 0.486 mg/L of air). EO-based nano-insecticides, used as cold aerosol and gel, are promising control methods against stored product pests, which can be integrated and combined with other sustainable biorational approaches. Full article

(This article belongs to the Special Issue Sustainable Defense Strategies for Pest Management)

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