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Isofuranodiene is a bioactive furanosesquiterpene occurring as the major volatile compound in the essential oil from Smyrnium olusatrum (Apiaceae). It has a notable potentiality to be used as a botanical insecticide. However, its low solubility together with susceptibility to oxidation and thermal degradation limits its application on a wide scale. To face these challenges, isofuranodiene was encapsulated in stable microemulsions (MEs) at two concentrations (ME 750: 0.75%, ME 375: 0.375%). We assessed the larvicidal activity in the short term and after several days of exposure of pure isofuranodiene and its MEs against the filariasis vector Culex quinquefasciatus. The impact of ME-based larvicide at sublethal concentrations on adult emergence was evaluated. Finally, to shed light on potential ecotoxicology risks for nontarget invertebrates, MEs were tested on the aquatic microcrustacean Daphnia magna and on the earthworm Eisenia fetida. Pure isofuranodiene and S. olusatrum leaf essential oil, used as controls, showed their potential as mosquito larvicidal agents (LC50 of 29.2 and 18.6 μL L−1, respectively). Isofuranodiene formulated in ME 750 was effective against C. quinquefasciatus larvae, leading to significant larval mortality over time and a marked decrease in adult emergence. Both isofuranodiene MEs showed little impact on the nontarget aquatic microcrustacean Daphnia magna (ME 750 and ME 375: mortality < 19% after 48 h of exposure at 32 mL L−1 and 20 mL L−1, respectively) as well as on earthworms (ME 750 and ME 375: no mortality and mortality < 7% after 14 days of exposure to 1000 mg kg−1, respectively), outlining their potential employ in vector control operations. [ABSTRACT FROM AUTHOR]

[Display omitted] • The development of green insecticides for real-world use is a major challenge. • This review focuses on Apiaceae-borne botanicals effectiveness against mosquitoes. • Essential oils and main constituents as mosquitocidal/repellent agents are reviewed. • Modes of action of Apiaceae essential oils and their major compounds are discussed. • Toxicity on non-target species and micro/nano-formulation development is analysed. Apiaceae is a family encompassing medicinal and aromatic plants. They produce essential oils (EOs) inside oil canals, known as ducts and vittae, which occur in their vegetative and reproductive organs. Given the high EO yields and the availability of raw material from cultivations widespread all over the world, Apiaceae are exploitable for different industrial applications. An interesting perspective is their utilization in the fabrication of botanical insecticides effective against insect vectors of public importance such as mosquitoes, aiming to be eco-friendly alternatives to synthetic insecticides. On this basis, in the current review, we collected scientific evidence supporting the use of Apiaceae EOs and their major constituents as active ingredients in insecticidal formulations against larvae and adults of several mosquitoes that are important pathogen vectors (e.g., Anopheles , Aedes and Culex species). For this purpose, we analysed the published data on their larvicidal, ovicidal, oviposition deterrent, pupicidal, adulticidal, and repellent effects, using efficacy thresholds as in the case of larvicidal activity (LC 50 (lethal concentration killing 50 % of the exposed population) < 50 ppm). Toxicity to non-target organisms, including vertebrates, has also been reviewed. The major EO constituents have been highlighted, each with its spectrum of mosquitocidal activity, providing insights on their multiple modes of action. The urgent need to develop highly stable micro/nano-formulations for real-world use has been outlined. Current weaknesses and strengths in the steps toward the development of botanical insecticides have been analysed to increase awareness of the future challenges necessary to open the doors to the industrial utilization of Apiaceae EOs by agrochemical companies. [ABSTRACT FROM AUTHOR]

Formulation development and non-target effect studies are two crucial steps for the registration of new botanical insecticides. Previous reports put in evidence the potential of hemp (Cannabis sativa L.) essential oil (EO) as a new candidate ingredient for developing green insecticides. However, the validation of its target and non-target effects after proper encapsulation is missing so far. In the current work, we investigated the insecticidal efficacy of the EO obtained from the hemp variety 'Kompolti', and we optimized its formulation development into a nanoemulsion (NE). The latter was assayed against larvae of Culex quinquefasciatus Say, a well-known vector of Wuchereria bancrofti Cobbold, avian malaria, and several arboviruses, such as Western equine encephalitis virus, St. Louis encephalitis virus, West Nile virus, and Zika virus. Considering the percentage of encapsulated EO (7.5% w/w), the developed NE showed mortality on Cx. quinquefasciatus larvae, in terms of LC 50(90) values [72.2 (207.2) ppm], like those of pure EO [50.8(142.3) ppm]. Non-target toxicity experiments showed limited toxicity on the aquatic microcrustacean Daphnia magna Straus (i.e., mortality <16% after 48 h of exposure to the EO-based NE at the LC 90 estimated on mosquito larvae). Considering that the LC 50 values detected in this study are lower than those belonging to many EOs, and that the application at sublethal doses caused mortality between 39.1% and 40.8% as well as a reduction in mosquito fertility resulting in a reduction in natality of 40.4% and 45.1% for the EO and EO-based NE, respectively, both products may be considered as potential environmentally friendly and sustainable insecticides. [Display omitted] • Kompolti hemp essential oil was encapsulated in nanoemulsions. • The insecticidal efficacy of hemp essential oil and its nanoemulsion was assessed. • Both formulations had high acute toxicity on Culex quinquefasciatus larvae. • Both products had limited impact on the aquatic microcrustacean Daphnia magna. [ABSTRACT FROM AUTHOR]

The development of effective control strategies targeting non-native ambrosia beetles (Coleoptera: Curculionidae: Scolytinae and Platypodinae) represents an emerging challenge. This is due both to their rapid spread into climatically suitable newly invaded regions rich in susceptible host plants and to the limited knowledge concerning sustainable management tools. In this context, the use of botanical insecticides, such as plant essential oils (EOs), is considered a promising option in Integrated Pest Management (IPM) strategies as an alternative to conventional insecticides for sustainable crop protection. Here, the impact of five EO nanoemulsions (Rosmarinus officinalis L. cultivar verbenone, Carlina acaulis L., Laurus nobilis L., Cupressus sempervirens L., and Betula alba L.) on the choice behavior, host colonization and progeny production by the invasive ambrosia beetle Xylosandrus compactus (Eichhoff) was evaluated under laboratory and semi-field conditions. The chemical composition of tested EOs was firstly evaluated by means of gas chromatography-mass spectrometry (GC-MS) analyses. Then, EO nanoemulsions were prepared and characterized through dynamic light scattering (DLS). Tested EO nanoemulsions showed single or bimodal droplet size distributions in the nanometric range. Results highlighted a significant repellent activity of R. officinalis cv. verbenone and C. acaulis EO nanoemulsions (at 3% EO concentration). However, the trend for repellence of the R. officinalis EO against the beetle was not confirmed at decreasing EO concentrations (i.e., 1% and 0.5%). Nanoemulsions based on C. acaulis EO significantly affected the beetle choices regardless of the tested EO concentration. Indeed, in no choice bioassays, a significantly lower number of individuals started infesting stems treated with these nanoemulsions. On the other hand, no effect of the EO treatment was found on the number of offspring produced by survived beetle females. The repellence by R. officinalis and C. acaulis EOs was confirmed in semi-field conditions. Overall, our findings provide new insights toward the use of R. officinalis and C. acaulis EOs as repellents of X. compactus , suggesting their future incorporation in non-chemical strategies, such as 'push-pull', as part of sustainable IPM packages targeting this invasive pest. [Display omitted] • Little is known about the use of plant essential oils for managing Xylosandrus ambrosia beetles. • Essential oils of Rosmarinus officinalis cv verbenone and Carlina acaulis alter host colonization by Xylosandrus compactus. • Nanoemulsions based on Carlina acaulis EO repelled the beetle regardless of the tested EO concentration. [ABSTRACT FROM AUTHOR]

Carlina acaulis L., belonging to the Asteraceae (Compositae) family, is a perennial herb native to the Alps, which has a long history as a food and traditional remedy , being one of the most important medicinal plants in Europe. Its reported uses go from diuretic, cholagogic, and antibacterial agent for the treatment of gastritis, skin diseases, acne, eczema, and ulcers. Even if this plant presents a rich phytocomplex, its root essential oil (EO) is the product that surely raised most research interest. It has the exceptional feature of having as main constituent the polyacetylene carlina oxide, and is currently listed among botanicals employable in food supplements in Europe. This EO and carlina oxide showed an encouraging bioactivity on a variety of bacteria and fungi, such as Staphylococcus aureus , Escherichia coli , Klebsiella pneumoniae , Pseudomonas aeruginosa , Proteus vulgaris , Candida albicans and C. glabrata. Moreover, these products showed marked insecticidal and acaricidal activities against insect pests and vectors of medical, agricultural, and economic importance, revealing to be promising in the horizon of botanical insecticides and acaricides. Its EO as well as carlina oxide resulted to be active on vectors, e.g. Culex quinquefasciatus, urban and livestock pests e.g. Musca domestica , stored product pests e.g. Acarus siro , Trogoderma granarium and Prostephanus truncatus , and agricultural pests, e.g. Lobesia botrana , Bactrocera oleae and Ceratitis capitata, among others. These insecticidal properties are also accompanied by low-to-moderate toxicity on non-target organisms such as earthworms and aquatic microcrustaceans, as well as on vertebrate cells and mammals. Innovative formulations have been developed and tested for applying these products in real-world conditions with encouraging results. Different cultivation systems of C. acaulis have been carried out, with classic field cultivation having the greatest advantage over other systems, such as hydroponic and in vitro micropropagation in terms of insecticidal and acarcicidal compound yield. This review puts a focus for the first time on C. acaulis , its active compounds and its potential against vectors, pests, and pathogens, and on current issues related to its cultivation on a large-scale level. Moreover, its biological properties and related encapsulation techniques developed are extensively reviewed. [Display omitted] • Carlina acaulis potential as a green insecticide and acaricide was reviewed. • Carlina oxide was examined as the main responsible for the insecticidal action. • Non-target toxicity was investigated. • Challenges and perspectives for the plant cultivation were considered. • The crucial role of nanoformulations for essential oil delivery was discussed. [ABSTRACT FROM AUTHOR]

The growing interest in the development of green pest management strategies is leading to the exploitation of essential oils (EOs) as promising botanical pesticides. In this respect, nanotechnology could efficiently support the use of EOs through their encapsulation into stable nanoformulations, such as nanoemulsions (NEs), to improve their stability and efficacy. This technology assures the improvement of the chemical stability, hydrophilicity, and environmental persistence of EOs, giving an added value for the fabrication of natural insecticides effective against a wide spectrum of insect vectors and pests of public and agronomical importance. Carlina acaulis (Asteraceae) root EO has been recently proposed as a promising ingredient of a new generation of botanical insecticides. In the present study, a highly stable C. acaulis-based NE was developed. Interestingly, such a nanosystem was able to encapsulate 6% (w/w) of C. acaulis EO, showing a mean diameter of around 140 nm and a SOR (surfactant-to-oil ratio) of 0.6. Its stability was evaluated in a storage period of six months and corroborated by an accelerated stability study. Therefore, the C. acaulis EO and C. acaulis-based NE were evaluated for their toxicity against 1st instar larvae of the European grapevine moth (EGVM), Lobesia botrana (Denis & Schiffermüller, 1775) (Lepidoptera: Tortricidae), a major vineyard pest. The chemical composition of C. acaulis EO was investigated by gas chromatography–mass spectrometry (GC–MS) revealing carlina oxide, a polyacetylene, as the main constituent. In toxicity assays, both the C. acaulis EO and the C. acaulis-based NE were highly toxic to L. botrana larvae, with LC50 values of 7.299 and 9.044 µL/mL for C. acaulis EO and NE, respectively. The C. acaulis-based NE represents a promising option to develop highly stable botanical insecticides for pest management. To date, this study represents the first evidence about the insecticidal toxicity of EOs and EO-based NEs against this major grapevine pest. [ABSTRACT FROM AUTHOR]

Among the various innovative products obtainable from hemp (Cannabis sativa L.) waste biomass originating from different industrial processes, the essential oil (EO) deserves special attention in order to understand its possible application in different fields, such as cosmetics, pharmaceuticals, and botanical insecticides. For the purpose, in the present work, we studied the chemical composition of EOs obtained from different hemp varieties, namely Felina 32 and Carmagnola Selezionata (CS) using monoecious, male, and female inflorescences, and we evaluated their mosquitocidal activities on larvae and pupae of two main malaria vectors, Anopheles gambiae and An. stephensi. Then, in order to evaluate the safe use of hemp EOs for operators, the potential pro- or anti-inflammatory effect of hemp EOs together with their toxicological profile were determined on dermal fibroblasts and keratinocytes. Given the promising results obtained by insecticidal and anti-inflammatory studies, a preliminary evaluation of EOs encapsulation into nanoemulsions (NEs) has been performed with the aim to develop a formulation able to improve their poor physicochemical stability. Felina 32 and CS inflorescences provided EOs with an interesting chemical profile, with monoterpene and sesquiterpene hydrocarbons as the major components. This study highlighted the potential application of male inflorescences, which are usually discharged during hemp product processing. These EOs could be exploited as potential sustainable and eco-friendly insecticides, given their capability to be toxic against mosquitoes and the possibility to use them to prepare stable and safe formulations. The LC50 values found in this study (<80 ppm) are lower, on average, than those of many plant EOs, with the advantage of using an industrial waste product. From MTT assay and gene and protein expression analysis, EOs showed no cytotoxicity at the appropriate doses and exerted an anti-inflammatory effect on the human cell lines tested. These findings encourage further applied research on hemp EOs in order support their industrial exploitation. [ABSTRACT FROM AUTHOR]