Lethal and Sublethal Effects of Essential Oils From Artemisia khorassanica and Vitex pseudo-negundo Against Plodia interpunctella (Lepidoptera: Pyralidae)

Essential oil pharmaceuticals for killing ectoparasites on dogs

BACKGROUND

External parasites, particularly ticks and fleas, are among the most common problems affecting dogs. Chemical medicines are commonly used to prevent and eliminate such external parasites, but their improper use can cause adverse reactions, and the toxins they contain may remain in the environment.

OBJECTIVES

The objective of this study was to investigate the in vitro efficacy of Zanthoxylum limonella, citronella, clove, peppermint, and ginger essential oils against dog ticks and fleas and to test the sensitivity of dogs' skin to these essential oils.

METHODS

The five essential oils were tested for in vitro efficacy against ticks and fleas, and the two most effective essential oils were then tested on the dogs' skin.

RESULTS

The results revealed that these five essential oils at 16% concentrations effectively inhibited the spawning of female engorged ticks. In addition, all five essential oils had a strong ability to kill tick larvae at concentrations of 2% upward. Furthermore, 4% concentrations of the five essential oils quickly eliminated fleas, especially clove oil, which killed 100% of fleas within 1 h. A 50%, 90%, and 99% lethal concentration (LC50, LC90, and LC99) for the essential oils on tick larvae in 24 h were found to be low values. LC50, LC90, and LC99 for the essential oils on flea in 1 h was lowest values. Clove oil at 16% concentration was the most satisfactory essential oil for application on dogs' skin, with a low percentage of adverse effects.

CONCLUSIONS

This study confirmed the effectiveness of essential oils for practical use as tick and flea repellents and eliminators. Essential-oil-based pharmaceutical can replace chemical pesticides and provide benefits for both consumers and the environment.

Chemical Composition and Antifungal and Antibiofilm Effects of Vitex pseudo-negundo Essential Oil against Pathogenic Fungal Strains

Background

Vitex pseudo-negundo is a plant of the Lamiaceae family that grows in different parts of the world and the vicinity of seasonal rivers in Iran.

Methods

The chemical composition of the Vitex pseudo-negundo essential oils was distilled and evaluated using gas chromatography/mass spectrometry. The antifungal activity of the essential oils against the fungal strains was analyzed by broth microdilution methods as suggested by the Clinical and Laboratory Standards Institute. Furthermore, the antibiofilm activity of the Vitex pseudo-negundo essential oils was assessed using the XTT reduction assay.

Results

Based on GC/MS analysis, the major components of the Vitex pseudo-negundo essential oils were α-pinene, α-terpinyl acetate, limonene, and (E)-caryophyllene. The growth of tested yeasts was inhibited at concentrations ranging from 2 to 64 μl/mL. Vitex pseudo-negundo fruit essential oil was the most effective in inhibiting yeast growth. Moreover, the essential oils exhibited antifungal activity against filamentous fungi strains. Additionally, the biofilm formation of Candida albicans was inhibited by the leaf, flower, and fruit of the essential oils.

Conclusion

Considering the significant antifungal activities of these essential oils, they can be considered a potential source for formulating novel agents to control fungal infections.

Essential Oils in Urban Insect Management-A Review

The allures of city life have culminated in the rise of urban populations resulting in conditions that promote the establishment of certain insect pests. Globally, the public health significance of these urban insect pests is enormous, ranging from billions of dollars to loss of lives. Most chemical insecticides no longer provide the anticipated level of control, and significant insecticide resistance has been reported. Therefore, there has been a spike in interest for alternatives to conventional insecticides. Among them, natural products from plants such as essential oils (EOs) and essential oil components (EOCs) have enjoyed the most attention owing to widespread reports of efficacy and toxicity even against insecticide-resistant urban insects. Yet, there is no comprehensive synthesis on the extent and impact of the management of urban insects using EOs or EOCs. Such a review is highly relevant since it provides a means to assess the extent of progress made, shortfalls, limitations, and prospects. More so, we hope it can be used to make informed decisions and develop relevant policies reliably. We present the ranges of insecticidal effects of EOs, EOCs, and commercially available EO-based products from laboratory and field studies. Finally, we discuss the gaps in our knowledge and prospects for the sustainable use of EOs.

Traditional uses, phytochemistry, and pharmacology of genus Vitex (Lamiaceae)

Vitex, the genus of the family Lamiaceae, comprises of about 230 species mostly distributed in the warm regions of Europe and temperate regions of Asia. Several Vitex species have been used as folk medicine in different countries for the treatment of various kinds of diseases and ailments. The main aim of this review is to collect and analyze the scientific information available about the Vitex species regarding their chemical constituents and pharmacological activities. The phytochemical investigation of various Vitex species has resulted in the isolation of about 556 chemical constituents belong to various chemical category viz. iridoids, diterpenoids, triterpenoids, flavonoids, lignans, sesquiterpenoids, monoterpenoids, ecdysteroids, and others. The crude extracts of different Vitex species as well as pure phytochemicals exhibited a wide spectrum of in-vitro and in-vivo pharmacological activities. In the present review, the scientific literature data on the ethnopharmacological, phytochemical, and pharmacological investigations on the genus Vitex are summarized. More attention should be given in future research to evaluate the pharmacological potential with detailed mechanism of actions for the pure compounds, extracts of plants from this genus. Moreover, their clinical study is needed to justify their use in modern medicine and to further exploring this genus for new drug discovery.

Lethal and behavioural effects of a green insecticide against an invasive polyphagous fruit fly pest and its safety to mammals

Plant essential oil-based insecticides, with special reference to those that may be obtained from largely available biomasses, represent a valuable tool for Integrated Pest Management. However, the sublethal effects and the potential effects on aggressive insect traits of these green insecticides are understudied. Herein, the lethal and sub-lethal effects of the carlina oxide, constituting more than 97% of the whole Carlina acaulis (Asteraceae) root essential oil (EO), were determined against an invasive polyphagous tephritid pest, Ceratitis capitata (medfly). The carlina oxide was formulated in a mucilaginous solution containing carboxymethylcellulose sodium salt, sucrose, and hydrolysed proteins, showing high ingestion toxicity on medfly adults. The behavioural effects of carlina oxide at LC₁₀ and LC₃₀ were evaluated on the medfly aggressive traits, which are crucial for securing reproductive success in both sexes. Insecticide exposure affected the directionality of aggressive actions, but not the aggression escalation intensity and duration. The EO safety to mammals was investigated by studying its acute toxicity on the stomach, liver, and kidney of rats after oral administration. Only the highest dose (1000 mg/kg) of the EO caused modest neurological signs and moderate effects on the stomach, liver, and kidney. The other doses, which are closer to the practical use of the EO when formulated in protein baits, did not cause side effects. Overall, C. acaulis-based products are effective and safe to non-target mammals, deserving further consideration for eco-friendly pesticide formulations.

Lethal and Sublethal Effects of Proteus, Matrine, and Pyridalyl on Frankliniella occidentalis (Thysanoptera: Thripidae)

The western flower thrips (WFT), Frankliniella occidentalis (Pergande) is one of the most harmful pests of crops in greenhouses and fields. Considering the need for studies that introduce new insecticides for control of the WFT, the leaf dip method was carried out to study the acute toxicity of Proteus, matrine, and pyridalyl to adult thrips, and life tables were constructed to assess the impacts of sublethal concentrations (LC25) of these insecticides on the development and reproduction of the F1 generation. Bioassays showed that the toxicity of matrine (LC50: 45.9 µl ml-1) and Proteus (LC50: 54.5 µl ml-1) was higher than pyridalyl (LC50: 176.5 µl ml-1). At LC25 concentration, both Proteus and matrine prolonged the development period and reduced the survival rate of eggs, larval stages, and pupae in the F1 generation. Also, the adults' longevity, oviposition duration, and the cumulative number of eggs laid per female (fecundity) were decreased significantly. Sublethal concentrations of Proteus and matrine inhibited the population growth rate relative to the control based on the predicted number of offspring. The lowest net reproductive rate (R0), intrinsic rate of increase (r), and finite rate of increase (λ) were estimated for Proteus (7.02 offspring/individual, 0. 0838 d-1, and 1. 08 d-1, respectively). In contrast, the WFT F1 generation that resulted from parent adults treated with pyridalyl was neither affected in their developmental time, nor fecundity, or the intrinsic rate of increase. According to our findings, all tested insecticides, especially Proteus, showed good potential for use in integrated pest management strategies against F. occidentalis.

Synergistic Field Crop Pest Management Properties of Plant-Derived Essential Oils in Combination with Synthetic Pesticides and Bioactive Molecules: A Review

The management of insect pests and fungal diseases that cause damage to crops has become challenging due to the rise of pesticide and fungicide resistance. The recent developments in studies related to plant-derived essential oil products has led to the discovery of a range of phytochemicals with the potential to combat pesticide and fungicide resistance. This review paper summarizes and interprets the findings of experimental work based on plant-based essential oils in combination with existing pesticidal and fungicidal agents and novel bioactive natural and synthetic molecules against the insect pests and fungi responsible for the damage of crops. The insect mortality rate and fractional inhibitory concentration were used to evaluate the insecticidal and fungicidal activities of essential oil synergists against crop-associated pests. A number of studies have revealed that plant-derived essential oils are capable of enhancing the insect mortality rate and reducing the minimum inhibitory concentration of commercially available pesticides, fungicides and other bioactive molecules. Considering these facts, plant-derived essential oils represent a valuable and novel source of bioactive compounds with potent synergism to modulate crop-associated insect pests and phytopathogenic fungi.

Methyl Benzoate Is Superior to Other Natural Fumigants for Controlling the Indian Meal Moth (Plodia interpunctella)

Simple Summary

Globally, the Indian meal moth is an insect pest of stored goods and manufactured foodstuffs. Synthetic fumigants, such as phosphine and methyl bromide, are widely used agents to control this species. However, due to the development of resistance and increasing concern about the potential adverse effects of synthetic fumigants, it is now necessary to identify environmentally friendly alternatives. Naturally occurring compounds, such as essential oils (EOs), are perhaps the most promising alternative sources; many have been successfully used as active ingredients in contact-based control products, repellents, and fumigants. Methyl benzoate (MBe) is an environmentally friendly, food-safe, natural insecticide that offers a possible alternative to synthetic equivalents. Here, we evaluated the fumigant toxicity of MBe against adults of the Indian meal moth and found that it had great potential for the control of these insect pests in stored products.

Abstract

The Indian meal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), is an insect pest that commonly affects stored and postharvest agricultural products. For the control of insect pests and mites, methyl benzoate (MBe) is lethal as a fumigant and also causes contact toxicity; although it has already been established as a food-safe natural product, the fumigation toxicity of MBe has yet to be demonstrated in P. interpunctella. Herein, we evaluated MBe as a potential fumigant for controlling adults of P. interpunctella in two bioassays. Compared to the monoterpenes examined under laboratory conditions, MBe demonstrated high fumigant activity using a 1-L glass bottle at 1 μL/L air within 4 h of exposure. The median lethal concentration (LC₅₀) of MBe was 0.1 μL/L air; the median lethal time (LT₅₀) of MBe at 0.1, 0.3, 0.5, and 1 μL/L air was 3.8, 3.3, 2.8, and 2.0 h, respectively. Compared with commercially available monoterpene compounds used in pest control, MBe showed the highest fumigant toxicity (toxicity order as follows): MBe > citronellal > linalool > 1,8 cineole > limonene. Moreover, in a larger space assay, MBe caused 100% mortality of P. interpunctella at 0.01 μL/cm³ of air after 24 h of exposure. Therefore, MBe can be recommended for use in food security programs as an ecofriendly alternative fumigant. Specifically, it provides another management tool for curtailing the loss of stored food commodities due to P. interpunctella infestation.

Toxicity and deleterious effects of Artemisia annua essential oil extracts on mulberry pyralid (Glyphodes pyloalis)

Botanical extracts are an important source of bio-pesticides and are generally considered safe to the environment. Artemisia annua L, a medicinal plant, well known for its antimalarial potential, was evaluated as a source of a type of essential oil collected during vegetative growth stage against Glyphodes pyloalis Walker. The main chemical components of the essential oil at vegetative stage of Artemisia annua was analyzed by GC- MS and contained 1,8-cineole (18.68%), Camphor (11.4%), α-Pinene (9.3%) and 3-Carene (6.3%). The LC₅₀ of this plant oil was estimated to be 0.652% W/V and 2.585 μL/L air incorporated orally and fumigation, respectively. The digestive enzymes such as α-amylases, Proteases, Lipases and α- and β-glucosidases were considereably inhibited in treated larvae compared with controls. Similarly, the amount of protein, glucose, and triglyceride were decreased in the treated larvae by methods used. The lower hemocyte numbers, nodule formation and activity of phenoloxidases after injection of Beauveria bassiana and latex beads showed its EO effect on immunity. The anatomy of the larval midgut after treatment showed degeneration in digestive cells. Emerging adult's ovaries showed significant changes in the ovarian sheath and lack of yolk spheres. The present investigation in accordance with our previous studies may ultimately lead to a formulation in controlling this notorious pest especially in mulberry orchards where the use of conventional chemicals is restricted.

Toxic, Oviposition Deterrent and Oxidative Stress Effects of Thymus vulgaris Essential Oil against Acanthoscelides obtectus

The bean weevil Acanthoscelides obtectus Say (Coleoptera: Chrysomelidae: Bruchinae) can cause significant losses in production of its primary host common bean Phaseolus vulgaris L. To avoid bean protection with environmentally risky chemical insecticides and provide sustainable and safe production of food, new pest management methods based on natural compounds are investigated. In the present study, we evaluated protective potential of the essential oil (EO) from the common thyme Thymus vulgaris L. applied on bean seeds. We assessed residual contact toxicity of thyme EO and its effects on A. obtectus longevity, oviposition and adult emergence. Furthermore, to elucidate the role of oxidative stress in thyme EO toxicity, we estimated the levels of oxidatively damaged proteins and lipids, as well as the level of thiols which have important role for antioxidant capacity. We found that thyme oil significantly reduced adult survival and longevity, induced oxidative damage to lipids and proteins and depleted protein and non-protein thiols in a concentration-dependent manner. Females appeared to be more tolerant to thyme oil treatment than males. Sublethal EO concentrations affected oxidative stress indices, deterred oviposition and strongly inhibited adult emergence. The results suggest that thyme oil has the potential to be used as an ecofriendly insecticide for A. obtectus control.

Plodia interpunctella (Lepidoptera: Pyralidae): Intoxication with essential oils isolated from Lippia turbinata (Griseb.) and analysis of neuropeptides and neuropeptide receptors, putative targets for pest control

The Indian meal moth Plodia interpunctella is a pest of stored products worldwide. Plant-derived essential oils with insecticidal activity could be safe products to control this species. The scarce information about the mode of action of most plant-derived products limits their use for the control of insect pests. Here, we demonstrate that an essential oil distilled from Lippia turbinata ("poleo") has insecticidal activity on P. interpunctella larvae. Furthermore, we performed a comprehensive characterization of P. interpunctella neuroendocrine system, in comparison with other lepidopteran species.

Insecticidal Activity of Artemisia vulgaris Essential Oil and Transcriptome Analysis of Tribolium castaneum in Response to Oil Exposure

Red flour beetle (Tribolium castaneum) is one of the most destructive pests of stored cereals worldwide. The essential oil (EO) of Artemisia vulgaris (mugwort) is known to be a strong toxicant that inhibits the growth, development, and reproduction of T. castaneum. However, the molecular mechanisms underlying the toxic effects of A. vulgaris EO on T. castaneum remain unclear. Here, two detoxifying enzymes, carboxylesterase (CarEs) and cytochrome oxidase P450 (CYPs), were dramatically increased in red flour beetle larvae when they were exposed to A. vulgaris EO. Further, 758 genes were differentially expressed between EO treated and control samples. Based on Gene Ontology (GO) analysis, numerous differentially expressed genes (DEGs) were enriched for terms related to the regulation of biological processes, response to stimulus, and antigen processing and presentation. Our results indicated that A. vulgaris EO disturbed the antioxidant activity in larvae and partially inhibited serine protease (SP), cathepsin (CAT), and lipase signaling pathways, thus disrupting larval development and reproduction as well as down-regulating the stress response. Moreover, these DEGs showed that A. vulgaris indirectly affected the development and reproduction of beetles by inducing the expression of genes encoding copper-zinc-superoxide dismutase (CuZnSOD), heme peroxidase (HPX), antioxidant enzymes, and transcription factors. Moreover, the majority of DEGs were mapped to the drug metabolism pathway in the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Notably, the following genes were detected: 6 odorant binding proteins (OBPs), 5 chemosensory proteins (CSPs), 14 CYPs, 3 esterases (ESTs), 5 glutathione S-transferases (GSTs), 6 UDP-glucuronosyltransferases (UGTs), and 2 multidrug resistance proteins (MRPs), of which 8 CYPs, 2 ESTs, 2 GSTs, and 3 UGTs were up-regulated dramatically after exposure to A. vulgaris EO. The residual DEGs were significantly down-regulated in EO exposed larvae, implying that partial compensation of metabolism detoxification existed in treated beetles. Furthermore, A. vulgaris EO induced overexpression of OBP/CYP, and RNAi against these genes significantly increased mortality of larvae exposed to EO, providing further evidence for the involvement of OBP/CYP in EO metabolic detoxification in T. castaneum. Our results provide an overview of the transcriptomic changes in T. castaneum in response to A. vulgaris EO.

Ecofriendly Approach for the Control of a Common Insect Pest in the Food Industry, Combining Polymeric Nanoparticles and Post-application Temperatures

One of the most common insect pests is Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), which affects different food commodities. A new effective approach for the management of insect pests is the development of new formulations based on essential oils (EO). However, few works informed about the relationship between insecticidal activity of EO or essential oils loaded polymeric nanoparticles (EOPN) and post-application temperature. In our work, palmarosa [Cymbopogon martinii (Roxb.) Watson], geranium (Geranium maculatum L.), and peppermint (Mentha piperita L.) oils were formulated in a polyethylene glycol 6000 matrix to obtain EOPN. Geranium and palmarosa EOPN had sizes of 259 and 191 nm, respectively; the encapsulation efficiency (EE) was close to 90%, and the samples were monodisperse. The sizes from peppermint EOPN were around 380 nm, with an EE of 72%, and were polidisperse. In a contact toxicity bioassay, the insecticidal effect of the oils was increased by all EOPN, with palmarosa oil being the most toxic. In addition, the oils and their nanoparticles showed a significantly negative temperature coefficient when applied by contact. In a fumigant bioassay, just palmarosa and peppermint EOPN enhanced the oil activity and palmarosa EO and EOPN showed the highest toxic effect. In this case, the EO and EOPN insecticidal activity was unaffected by environmental temperature variation.

Evaluation of tansy essential oil as a potential "green" alternative for gypsy moth control

The development of "green" alternatives to chemical pesticides could play a crucial role in integrated pest management (IPM). Their use is considered either as a substitution for or in addition to hazardous synthetic products. We analysed the influence of three concentrations of tansy (Tanacetum vulgare L.) essential oil (EO), previously characterised by GC-MS, on the survival and moulting of the 2nd instar and the nutritional indices of the 4th instar gypsy moth (Lymantria dispar L.) larvae. In a residual contact toxicity assessment, the exposure to tansy EO caused low mortality (< 10%) while larval development was significantly slowed down, i.e., the percentage of larvae that moulted into the 3rd instar was reduced. On the other hand, when tansy EO was incorporated into the diet (digestive toxicity assay), high mortality and a lack of moulting after 120 h of eating were recorded for the highest applied concentration of EO. During 48 h of feeding on EO-supplemented food at concentrations of 0.5 and 1% (v/v), the relative growth rate (RGR) of the 4th instar larvae significantly decreased, which can be explained by a significant reduction of the relative consumption rate (RCR) and significantly or marginally significantly lower efficiency of conversion of ingested food into insect biomass (ECI). Although the RCR was also reduced with the lowest applied EO concentration (0.1%), the ECI was not affected which meant the RGR was as high as it was for the control larvae. ECI changes, when two higher EO concentrations were applied, were due to a reduction in the efficiency of conversion of digested food into biomass (ECD), while approximate digestibility was unaffected by the presence of EO in the food. Our results on the significant negative effects of tansy EO on gypsy moth larval survival, development time, and nutritional physiology suggest that it could be considered in future designs for botanical insecticides for gypsy moth control.

Ultrasound assisted formation of essential oil nanoemulsions: Emerging alternative for Culex pipiens pipiens Say (Diptera: Culicidae) and Plodia interpunctella Hübner (Lepidoptera: Pyralidae) management

Over the last years, nanotechnology has contributed to the development of new botanical insecticides formulations based on essential oils (EO), which are safe for the human health and the environment. Nanoemulsions (NEs) can enhance the bioactivity of the EO to prevent the premature volatility and degradation of the active ingredients. In our work, geranium EO (Geranium maculatum L.) was used to develop micro and nanoemulsions adding Tween 80 as surfactant. For NEs formulation, ultrasound was applied and the physicochemical and ultrasound parameters were optimized: oil: surfactant ratio = 1:2, ultrasound power = 65 W, sonication time = 2 min, cycles = 30 on/20 off and ultrasonic probe distance = 3.7 cm. The NEs obtained had 13.58 nm and polydisperse index (PDI) values of 0.069. They were stored at 25 °C and were stable for 60 days. The present study also demonstrated the potential of NEs to enhance the toxicity of geranium EO against larvae of Culex pipiens pipiens (EO LC₅₀ = 80.97 ppm, NEs LC₅₀ = 48.27 ppm) and Plodia interpunctella (EO + β-cypermethrin LD₅₀ = 0.16 μg larvae^-1, NEs + β-cypermethrin LD₅₀ = 0.07 μg larvae^-1). Overall, our findings pointed out that NEs can increase twofold the insecticidal efficacy of EO, and thus, they can be considered further for the development of botanical insecticides.

Chemical composition and bioactivity of Vitex cofassus Reinw. extracts on the larval and pupal stages of Aedes aegypti

Aims and Objectives:

Materials and Methods:

Results:

Conclusion:

Essential Oils in Stored Product Insect Pest Control

Among botanical extracts used as insecticides, essential oils (EOs) are promising alternatives to chemical insecticides. EOs are synthesized by plants, and they play a key role in plant signaling processes including also attractiveness toward pollinators and beneficial insects. Plant species producing essential oils (over 17,000 species) are called aromatic plants and are distributed worldwide. Our review aims to evaluate research studies published in the last 15 years concerning the use of EOs in stored product protection. More than 50% of the retrieved manuscripts have been published by authors from Eastern countries (Iran, China, India, and Pakistan), investigating different aspects related to insect pest management (exposure route, effect on the target pest, and mode of action). Coleoptera was the most studied insect order (85.41%) followed by Lepidoptera (11.49%), whereas few studies targeted new emerging pests (e.g., Psocoptera). Almost all the trials were carried out under laboratory conditions, while no experiments were conducted under real operating conditions. Future research studies concerning the use of EOs as insecticides should focus on the development of insecticide formulations which could be successfully applied to different production realities.

Comparison of Life Table Parameters and Digestive Physiology of Rhyzopertha dominica (Coleoptera: Bostrichidae) Fed on Various Barley Cultivars

In this study, the effect of 20 barley cultivars were evaluated on the life table parameters and digestive enzymatic activity of the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) under laboratory conditions (28 ± 1°C, 60 ± 5% RH, and a photoperiod of 16:8 (L:D) h). Among barley cultivars tested developmental time of R. dominica immature stages was longest on cultivar Bahman (61.00) and shortest on Mahoor (46.60 d). The lowest realized fecundities were recorded for insects reared on cultivar Bahman (217.60); and the highest ones were observed for insects reared on Sahra (348.05 eggs/female). The net reproductive rate (R0) was significantly affected by various barley cultivars being lowest on cultivar Bahman (53.98) and highest on Mahoor (146.79 offspring/female). Records for intrinsic rates of increase (rm) were lowest on cultivar Dasht (0.043) and the highest on Mahoor (0.066 day-1). The highest levels of amylolytic and proteolytic activity were recorded on cultivars Mahoor and EBYT-92-10, respectively. By contrast, the insects reared on cultivars Dasht had the lowest levels of α-amylase and general protease activity. Correlation analyses showed that high correlations existed between the immature period, adult longevity, fecundity, and life table parameters on one side and protein content and particle size index on the other. The results of our experiments showed that cultivar Mahoor was a relatively susceptible and cultivars Bahman and Dasht were relatively resistant to R. dominica which could be useful in the development of IPM programs for this pest in store.

The Genus Artemisia: a 2012-2017 Literature Review on Chemical Composition, Antimicrobial, Insecticidal and Antioxidant Activities of Essential Oils

Essential oils of aromatic and medicinal plants generally have a diverse range of activities because they possess several active constituents that work through several modes of action. The genus Artemisia includes the largest genus of family Asteraceae has several medicinal uses in human and plant diseases aliments. Extensive investigations on essential oil composition, antimicrobial, insecticidal and antioxidant studies have been conducted for various species of this genus. In this review, we have compiled data of recent literature (2012-2017) on essential oil composition, antimicrobial, insecticidal and antioxidant activities of different species of the genus Artemisia. Regarding the antimicrobial and insecticidal properties we have only described here efficacy of essential oils against plant pathogens and insect pests. The literature revealed that 1, 8-cineole, beta-pinene, thujone, artemisia ketone, camphor, caryophyllene, camphene and germacrene D are the major components in most of the essential oils of this plant species. Oils from different species of genus Artemisia exhibited strong antimicrobial activity against plant pathogens and insecticidal activity against insect pests. However, only few species have been explored for antioxidant activity.

Fumigant Toxicity and Sublethal Effects of Artemisia khorassanica and Artemisia sieberi on Sitotroga cerealella (Lepidoptera: Gelechiidae)

Fumigant toxicity and sublethal effects of essential oils from Artemisia khorassanica Podl. and Artemisia sieberi Bess were investigated against adults of Sitotroga cerealella Olivier. To assess the sublethal effects, adult moths were exposed to the LC30 of each essential oil, and life table parameters of the surviving S. cerealella were studied. Higher fumigant toxicity of A. khorassanica (LC50: 7.38 µl/liter air) than A. sieberi (LC50: 9.26 µl/liter air) was observed against S. cerealella. Also, the insecticidal effects of A. khorassanica (LT50: 9.01 h) were faster than A. sieberi (LT50: 14.37 h). A significant extension was observed in the developmental time (egg to adult) of S. cerealella treated with the essential oils. In addition, fecundity of S. cerealella reduced by 25.29 and 35.78% following exposure to sublethal concentrations of A. sieberi and A. khorassanica, respectively. Both tested essential oils caused a significant reduction in the gross and net reproductive rates, intrinsic rate of increase (rm), and finite rate of increase of S. cerealella. The rm values following exposure to A. sieberi, A. khorassanica, and control were 0.098, 0.094, and 0.107 d-1, respectively. The results of this study suggest that tested essential oils have a good potential to apply in integrated pest management of S. cerealella.