Artemisia spp. essential oils against the disease-carrying blowfly Calliphora vomitoria

Assessing the effects of a commercial fungicide and an herbicide, alone and in combination, on Apis mellifera: Insights from biomarkers and cognitive analysis

Agrochemicals play a vital role in protecting crops and enhancing agricultural production by reducing threats from pests, pathogens and weeds. The toxicological status of honey bees can be influenced by a number of factors, including pesticides. While extensive research has focused on the lethal and sublethal effects of insecticides on individual bees and colonies, it is important to recognise that fungicides and herbicides can also affect bees' health. Unfortunately, in the field, honey bees are exposed to mixtures of compounds rather than single substances. This study aimed to evaluate the effects of a commercial fungicide and a commercial herbicide, both individually and in combination, on honey bees. Mortality assays, biomarkers and learning and memory tests were performed, and the results were integrated to assess the toxicological status of honey bees. Neurotoxicity (acetylcholinesterase and carboxylesterase activities), detoxification and metabolic processes (glutathione S-transferase and alkaline phosphatase activities), immune system function (lysozyme activity and haemocytes count) and genotoxicity biomarkers (Nuclear Abnormalities assay) were assessed. The fungicide Sakura® was found to activate detoxification enzymes and affect alkaline phosphatase activity. The herbicide Elegant 2FD and the combination of both pesticides showed neurotoxic effects and induced detoxification processes. Exposure to the herbicide/fungicide mixture impaired learning and memory in honey bees. This study represents a significant advance in understanding the toxicological effects of commonly used commercial pesticides in agriculture and contributes to the development of effective strategies to mitigate their adverse effects on non-target insects.

Leaf and Flower Extracts from the Dwarf Elder (Sambucus ebulus): Toxicity and Repellence against Cosmopolitan Mosquito-Borne Diseases Vectors

As there has been no scientific evidence of the bioactivity of Sambucus ebulus (Adoxaceae) extracts against insects, we chemically characterized S. ebulus leaves and flowers extracted in methanol and water. The crude extracts, phenolic compounds, and amino acids isolated were tested as larvicides against the fourth-instar larvae of Aedes albopictus and Culex pipiens (Diptera: Culicidae). To understand their mode of action, we evaluated the in vitro acetylcholinesterase (AChE) inhibitor effect of the crude extracts on the two mosquito larvae through a colorimetric method. Furthermore, the deterrent effect of the crude extracts against ovipositing Ae. albopictus females was assessed in the open field. Twelve phenylpropanoids and fourteen amino acids were detected in the extracts, with a prevalence of hydroxycinnamic acids and nonaromatic amino acids. The most toxic compound to Ae. albopictus larvae after 24 h was gallic acid, followed by the crude S. ebulus leaf extract; on Cx. pipiens, it was the crude flower extract. The AChE test showed higher inhibition on both mosquito species exerted by the leaf extract if compared to the flower extract, and it also deterred oviposition by Ae. albopictus females starting from the third day. The results indicated that vegetal extracts could effectively help in the integrated vector management of mosquitoes.

Chitosan as a Control Tool for Insect Pest Management: A Review

Chitosan, a polysaccharide derived from the deacetylation of chitin, is a versatile and eco-friendly biopolymer with several applications. Chitosan is recognized for its biodegradability, biocompatibility, and non-toxicity, beyond its antimicrobial, antioxidant, and antitumoral activities. Thanks to its properties, chitosan is used in many fields including medicine, pharmacy, cosmetics, textile, nutrition, and agriculture. This review focuses on chitosan's role as a tool in insect pest control, particularly for agriculture, foodstuff, and public health pests. Different formulations, including plain chitosan, chitosan coating, chitosan with nematodes, chitosan's modifications, and chitosan nanoparticles, are explored. Biological assays using these formulations highlighted the use of chitosan-essential oil nanoparticles as an effective tool for pest control, due to their enhanced mobility and essential oils' prolonged release over time. Chitosan's derivatives with alkyl, benzyl, and acyl groups showed good activity against insect pests due to improved solubility and enhanced activity compared to plain chitosan. Thus, the purpose of this review is to provide the reader with updated information concerning the use and potential applications of chitosan formulations as pest control tools.

Chitosan and Essential Oils Combined for Beef Meat Protection against the Oviposition of Calliphora vomitoria, Water Loss, Lipid Peroxidation, and Colour Changes

Meat production has a higher economic and ecological impact than other commodities. The reduction in meat loss and waste throughout the whole supply chain is a demanding challenge. In recent years, the interest in the food-grade polysaccharide chitosan (CH) and essential oils (EOs) employed as allies in meat protection has increased. In this work, we selected five EOs obtained from plants traditionally used as spices, and after their chemical characterisation, a trained panel of expert sensorial analysts determined that, among them, Laurus nobilis (Lauraceae) and Piper nigrum (Piperaceae) EOs were the most suitable to season meat. Therefore, the effect of CH, the L. nobilis and P. nigrum EOs, and EOs-enriched CH solutions on meat was tested to assess how they deter the oviposition behaviour of the blowfly Calliphora vomitoria (Diptera: Calliphoridae) and against water loss, lipid peroxidation, and colour changes. All the applied treatments, compared to the control, did not accelerate meat dehydration but increased colour lightness, an attractive feature for consumers, and discouraged the blowfly's oviposition. In particular, the P. nigrum EO-enriched CH was the most active in repelling C. vomitoria without negatively affecting the organoleptic qualities and shelf-life of meat.

Artemisia Species with High Biological Values as a Potential Source of Medicinal and Cosmetic Raw Materials

Artemisia species play a vital role in traditional and contemporary medicine. Among them, Artemisia abrotanum, Artemisia absinthium, Artemisia annua, Artemisia dracunculus, and Artemisia vulgaris are the most popular. The chemical composition and bioactivity of these species have been extensively studied. Studies on these species have confirmed their traditional applications and documented new pharmacological directions and their valuable and potential applications in cosmetology. Artemisia ssp. primarily contain sesquiterpenoid lactones, coumarins, flavonoids, and phenolic acids. Essential oils obtained from these species are of great biological importance. Extracts from Artemisia ssp. have been scientifically proven to exhibit, among others, hepatoprotective, neuroprotective, antidepressant, cytotoxic, and digestion-stimulating activities. In addition, their application in cosmetic products is currently the subject of several studies. Essential oils or extracts from different parts of Artemisia ssp. have been characterized by antibacterial, antifungal, and antioxidant activities. Products with Artemisia extracts, essential oils, or individual compounds can be used on skin, hair, and nails. Artemisia products are also used as ingredients in skincare cosmetics, such as creams, shampoos, essences, serums, masks, lotions, and tonics. This review focuses especially on elucidating the importance of the most popular/important species of the Artemisia genus in the cosmetic industry.

Predation Capacity of the Banded Thrips Aeolothrips intermedius for the Biological Control of the Onion Thrips Thrips tabaci

Simple Summary

Aeolothrips intermedius is a native predator of Thrips tabaci, one of the most harmful thrips for many open field crops. Our study evaluated the predatory efficiency of A. intermedius against T. tabaci adults. The results showed that A. intermedius can be considered a promising resource for the biological control of onion thrips.

Abstract

The onion thrips, Thrips tabaci, is a main insect pest for many field crops worldwide, with a particular preference for the species of the genus Allium. Aeolothrips intermedius is a banded thrips, whose larvae are considered the primary native predator of T. tabaci. Due of their predatory behaviour, A. intermedius larvae are considered a good candidate for biological control against thrips pests. However, limited information is available on the specific predation rate of A. intermedius against T. tabaci. The aim of our study was to evaluate the predatory efficiency of A. intermedius larvae against T. tabaci adults. Predation assays, performed under laboratory conditions, indicated that A. intermedius larvae begin to prey after an average of about 23 min, and the time taken by an A. intermedius larva to capture and subdue the prey until its death is about 26 min. Furthermore, the maximum number of prey that the A. intermedius larvae are able to kill in 12 h is up to eight adults of T. tabaci/A. intermedius larva.

Natural plant products as effective alternatives to synthetic chemicals for postharvest fruit storage management

Fruits contain enormous source of vitamins that provides energy to the human body. These are also affluent in essential and vital vitamins, minerals, fiber, and health-promoting components, which has led to an increase in fruit consumption in recent years. Though fruit consumption has expanded considerably in recent years, the use of synthetic chemicals to ripen or store fruits has been steadily increasing, resulting in postharvest deterioration. Alternatives to synthetic chemicals should be considered to control this problem. Instead of utilizing synthetic chemicals, this study suggests using natural plant products to control postharvest decay. The aim of this study indicates how natural plant products can be useful and effective to eliminate postharvest diseases rather than using synthetic chemicals. Several electronic databases were investigated as information sources, including Google Scholar, PubMed, Web of Science, Scopus, ScienceDirect, SpringerLink, Semantic Scholar, MEDLINE, and CNKI Scholar. The current review focused on the postharvest of fruits has become more and more necessary because of these vast demands of fruits. Pathogen-induced diseases are the main component and so the vast portion of fruits get wasted after harvest. Besides, it may occur harmful during harvesting and subsequent handling, storage, and marketing and after consumer purchasing and also causes for numerous endogenous and exogenous diseases via activating ROS, oxidative stress, lipid peroxidation, etc. However, pathogenicity can be halted by using postharvest originating natural fruits containing bioactive elements that may be responsible for the management of nutritional deficiency, inflammation, cancer, and so on. However, issues arising during the postharvest diseases must be controlled and resolved before releasing the horticultural commodities for commercialization. Therefore, the control of postharvest pathogens still depends on the use of synthetic fungicides; however, due to the problem of the development of the fungicide-resistant strains there is a good demand of public to eradicate the use of pesticides with the arrival of numerous diseases that are expanded in their intensity by the specific chemical product. By using of the organic or natural products for controlling postharvest diseases of fruits has become a mandatory step to take. In addition, antimicrobial packaging may have a greater impact on long-term food security by lowering the risk of pathogenicity and increasing the longevity of fruit shelf life. Taken together, natural chemicals as acetaldehyde, hexanal, eugenol, linalool, jasmonates, glucosinolates, essential oils, and many plant bioactive are reported for combating of the postharvest illnesses and guide to way of storage of fruits in this review.

Comparative Study of the Essential Oil and Hydrosol Composition of Sweet Wormwood (Artemisia annua L.) from Serbia

The most abundant volatile compounds of sweet wormwood (Artemisia annua L.) essential oil were artemisia ketone (25.4 %) and trans-caryophyllene (10.2 %), followed by 1,8-cineole, camphor, germacrene D and β-selinene. The major volatile compounds in the hydrosol were camphor (25.1 %), 1,8-cineole (20.5 %) and artemisia ketone (10.7 %), followed by trans-pinocarveol and yomogi alcohol. Tested essential oil was rich in oxygenated monoterpenes and sesquiterpene hydrocarbons, while the former were identified as the major class of volatile compounds in the hydrosol, due to higher water solubility. Classification of all sweet wormwood chemotypes, according to essential oil composition, in available literature (17 studies and 61 accessions) could be done according to four chemotypes: artemisia ketone+artemisia alcohol (most abundant), artemisia ketone, camphor and nonspecific chemotype. According to this classification, essential oil of sweet wormwood from this study belongs to artemisia ketone (content varied between 22.1 and 55.8 %). Bearing in mind that hydrosols are a by-product of industrial production of essential oils, and the fact that sweet wormwood hydrosol has high contents of camphor, 1,8-cineole and artemisia ketone, there is a great potential for the use of this aromatic plant primary processing waste product as a water replacement in cosmetic industry, beverages flavoring, for food preservation, as well as in post-harvest pre-storage treatments in organic agriculture.

Evaluating the Efficacy of 30 Different Essential Oils against Varroa destructor and Honey Bee Workers (Apis mellifera)

Simple Summary

Worldwide, mass losses of honey bee colonies are being observed more frequently due to Varroa mite infestation. Therefore, varroosis is considered a major problem in beekeeping participating to a large extent in colony collapse disorder. Except for direct damage of bees and suppressing their immune system caused by parasitism, Varroa mites transfer viral particles straight to bee hemolymph which can have a fatal impact. To control the mite population, several acaricidal treatments are used. Commonly used treatments are synthetic acaricides with a high risk of developing Varroa resistance population and contamination of bee products by acaricidal residues. Other commonly used treatments are organic acids, which are increasingly associated with damage of brood, adult bees, and premature deaths of queens. Therefore, in this study, we evaluated the varroacidal effect of 30 individual essential oils. The toxicity of the most effective oils selected by screening was subsequently tested on Varroa mites and adult honey bee workers simultaneously. In addition, the main components of these essential oils were specified. Several essential oils were proven to be effective against the adult female of Varroa mites and at the same dose safe for adult honey bee workers under laboratory conditions, especially manuka, peppermint, oregano, litsea, and cinnamon.

Abstract

Essential oils and their components are generally known for their acaricidal effects and are used as an alternative to control the population of the Varroa destructor instead of synthetic acaricides. However, for many essential oils, the exact acaricidal effect against Varroa mites, as well as the effect against honey bees, is not known. In this study, 30 different essential oils were screened by using a glass-vial residual bioassay. Essential oils showing varroacidal efficacy > 70% were tested by the complete exposure assay. A total of five bees and five mites were placed in the Petri dishes in five replications for each concentration of essential oil. Mite and bee mortality rates were assessed after 4, 24, 48, and 72 h. The LC₅₀ values and selectivity ratio (SR) were calculated. For essential oils with the best selectivity ratio, their main components were detected and quantified by GC-MS/MS. The results suggest that the most suitable oils are peppermint and manuka (SR > 9), followed by oregano, litsea (SR > 5), carrot, and cinnamon (SR > 4). Additionally, these oils showed a trend of the increased value of selective ratio over time. All these oils seem to be better than thymol (SR < 3.2), which is commonly used in beekeeping practice. However, the possible use of these essential oils has yet to be verified in beekeeping practice.

Andean Plants Essential Oils: A Scented Alternative to Synthetic Insecticides for the Control of Blowflies

Blowflies are vectors of microorganisms and human pathogens, and their maggots cause myiasis in vertebrates and infest and spoil meat and fish products. Essential oils (EOs) from spices were proven to be a safer and more sustainable alternative to synthetic insecticides for the control of blowflies and are suitable for protecting food from such pests. However, some EOs are not acceptable for environmental or topical applications due to their strong, unpleasant odour. In this study, we measured the acute toxicity and the repellence of two EOs extracted from the Andean plants Aloysia citrodora Palau and Bursera graveolens (Kunth) Triana and Planch., both known for their pleasant odour, against the blue blowfly Calliphora vomitoria (L.) (Diptera: Calliphoridae). We also compared their bioactivity with that of the Allium sativum L. EO, which is very effective but bad-smelling. The A. citrodora EO was mainly rich in oxygenated monoterpenes, the most abundant of which were geranial (26.8%) and neral (21.0%). The B. graveolens EO was chiefly composed of monoterpene hydrocarbons, mostly represented by limonene (46.2%). According to the sensory description, the best odour profile was associated with the A. citrodora EO, while the olfactory expression of the EO from B. graveolens was negatively affected by a strong odour of "mouldy lemon". The behavioural test showed that the A. citrodora EO was more repellent than that of A. sativum and, on the contrary, that the B. graveolens EO was attractive. The toxicity tests showed that the EOs of both Andean plants have a clear toxic effect on the C. vomitoria eggs and adults. In terms of ovicidal activity, there were no significant differences among the effects of the three tested EOs. On the adult flies, the toxicity of the two EOs of the Andean plants was much lower than that of A. sativum (LC₅₀ fumigation = 1.86 μL EO L^-1 air; LC₅₀ ingestion = 8.10 μL EO mL^-1 gel) both by fumigation (LC₅₀ = 23.66 and 25.30 μL EO L^-1 air for A. citrodora and B. graveolens, respectively) and ingestion (LC₅₀ = 36.65 and 44.97 μL EO mL^-1 gel for A. citrodora and B. graveolens, respectively), while, by contact, the A. citrodora EO (LD₅₀ = 0.27 μL EO insect^-1) was more toxic than the A. sativum EO (LD₅₀ = 0.46 μL EO insect^-1).

Artemisia dracunculus (Tarragon): A Review of Its Traditional Uses, Phytochemistry and Pharmacology

Artemisia dracunculus L. (tarragon), Asteraceae, is a species that has long been used in traditional Asian medicine, mainly in Iran, Pakistan, Azerbaijan and India. It is known as a spice species in Asia, Europe and the Americas. The raw materials obtained from this species are herb and leaf. The presence of essential oil with a highly variable composition, as well as flavonoids, phenolic acids, coumarins and alkamides, determines the medicinal and/or spice properties of the plant. In traditional Asian medicine, this species is used, for example, in the treatment of digestive system diseases, as an analgesic, hypnotic, antiepileptic, anti-inflammatory and antipyretic agent, and as an effective remedy in the treatment of helminthiasis. Nowadays, A. dracunculus is the subject of professional phytochemical and pharmacological researches. Pharmacological studies have confirmed its anti-inflammatory and analgesic effects known from traditional uses; they have also proved very important new findings regarding its biological activity, such as antioxidant, immunomodulating and anti-tumour activities, as well as hepatoprotective and hypoglycaemic effects. A. dracunculus has long-held an established position in the food industry as a spice. And its use is growing in the cosmetics industry. Moreover, it is the subject of biotechnological research focused mainly on the development of micro-propagation protocols.

Mulberry Protection through Flowering-Stage Essential Oil of Artemisia annua against the Lesser Mulberry Pyralid, Glyphodes pyloalis Walker

In the present study, the toxicity and physiological disorders of the essential oil isolated from Artemisia annua flowers were assessed against one of the main insect pests of mulberry, Glyphodes pyloalis Walker, announcing one of the safe and effective alternatives to synthetic pesticides. The LC₅₀ (lethal concentration to kill 50% of tested insects) values of the oral and fumigant bioassays of A. annua essential oil were 1.204 % W/V and 3.343 μL/L air, respectively. The A. annua essential oil, rich in camphor, artemisia ketone, β-selinene, pinocarvone, 1,8-cineole, and α-pinene, caused a significant reduction in digestive and detoxifying enzyme activity of G. pyloalis larvae. The contents of protein, glucose, and triglyceride were also reduced in the treated larvae by oral and fumigant treatments. The immune system in treated larvae was weakened after both oral and fumigation applications compared to the control groups. Histological studies on the midgut and ovaries showed that A. annua essential oil caused an obvious change in the distribution of the principal cells of tissues and reduction in yolk spheres in oocytes. Therefore, it is suggested that the essential oil from A. annua flowers, with wide-range bio-effects on G. pyloalis, be used as an available, safe, effective insecticide in the protection of mulberry.

Multi-biomarker approach and IBR index to evaluate the effects of different contaminants on the ecotoxicological status of Apis mellifera

The honeybee, Apis mellifera L. (Hymenoptera: Apidae), a keystone pollinator of wild plant species and agricultural crops, is disappearing globally due to parasites and diseases, habitat loss, genetic constraints, beekeeper management issues and to the widespread use of pesticides. Besides insecticides, widely studied in this species, honeybees are also exposed to herbicides and fungicides and heavy metals whose lethal and sublethal effects need to be investigated. In this context, our study aimed to evaluate the effects of fungicides and of heavy metals on honeybees and to develop and apply a multi-biomarker approach that include an Integrated Biological Index (IBRv2) to assess the toxicological status of this species. Biomarkers of neurotoxicity (AChE and CaE), metabolic alteration (ALP, and GST) and immune system (LYS, granulocytes) were measured, following honeybees' exposure to cadmium or to a crop fungicide, using the genotoxic compound EMS as positive control. A biomarker of genotoxicity (NA assay) was developed and applied for the first time in honeybees. At the doses tested, all the contaminants showed sublethal toxicity to the bees, highlighting in particular genotoxic effects. The data collected were analyzed by an IBRv2 index, which integrated the seven biomarkers used in this study. IBRv2 index increased with increasing cadmium or fungicide concentrations. The IBRv2 represents a simple tool for a general description of honeybees ecotoxicological health status. Results highlight the need for more in-depth investigations on the effects of fungicides on non-target organisms, such as honeybees, using sensitive methods for the determination of sublethal effects. This study contributes to the development of a multi-biomarker approach to be used for a more accurate ecotoxicological environmental monitoring of these animals.

Bioactivity of Different Chemotypes of Oregano Essential Oil against the Blowfly Calliphora vomitoria Vector of Foodborne Pathogens

Simple Summary

Calliphora vomitoria L. is a very common synanthropic blowfly. Since it is attracted by human food, it plays a main role in the transmission of foodborne diseases. Among aromatic plant essential oils (EOs), those of spices are the most suitable to protect food from insect pests. In the present work, we determined the bioactivity of three oregano EOs against C. vomitoria. The chemical analyses showed that the EOs belonged to three chemotypes, one with a prevalence of carvacrol and two with a prevalence of thymol. The bioassays showed that the bioactivity of the EOs significantly varies among chemotypes, with the thymol chemotype showing an overall higher efficacy compared to the carvacrol one.

Abstract

Blowflies play a substantial role as vectors of microorganisms, including human pathogens. The control of these insect pests is an important aspect of the prevention of foodborne diseases, which represent a significant public health threat worldwide. Among aromatic plants, spices essential oils (EOs) are the most suitable to protect food from insect pests. In this study, we determined the chemical composition of three oregano EOs and assessed their toxicity and deterrence to oviposition against the blowfly Calliphora vomitoria L. The chemical analyses showed that the EOs belonged to three chemotypes: one with a prevalence of carvacrol, the carvacrol chemotype (CC; carvacrol, 81.5%), and two with a prevalence of thymol, the thymol/p-cymene and thymol/γ-terpinene chemotypes (TCC and TTC; thymol, 43.8, and 36.7%, respectively). The bioassays showed that although all the three EOs chemotypes are able to exert a toxic activity against C. vomitoria adults (LD₅₀ from 0.14 to 0.31 μL insect⁻¹) and eggs (LC₅₀ from 0.008 to 0.038 μL cm⁻²) as well as deter the oviposition (Oviposition Activity Index, OAI, from 0.40 ± 0.04 to 0.87 ± 0.02), the bioactivity of oregano EOs significantly varies among the chemotypes, with the thymol-rich EOs (TCC and TTC) overall demonstrating more effectiveness than the carvacrol-rich (CC) EO.

Phytochemical Study on the Essential Oils of Tarragon (Аrtemisia dracunculus L.) Growing in Tajikistan and Its Comparison With the Essential Oil of the Species in the Rest of the World

The aerial parts of the tarragon ( Artemisia dracunculus) were collected around Kukteppa village, Ziddi, Varzob region of Tajikistan. The essential oil of tarragon was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. Forty-five compounds representing 99.8% of total oil were identified. Sabinene (29.1%), estragole (24.6%), limonene (7.8%), ( Z)-artemidin (4.9%), myrcene (4.8%), and ( E)-β-ocimene (4.0%) were components with a representation higher than 4% of the essential oils of aerial parts of tarragon. Hierarchical cluster analysis of А. dracunculus essential oils on the global phytogeographic origin based on 30 essential oil components and 105 samples (globally) of this species, indicated the existence of its 7 major chemotypes: ocimene, α-terpinene, capillene, methyl eugenol, mixed chemotype, ( Z)-artemidin, and estragol chemotypes. The essential oils of А. dracunculus showed weak antioxidant and antibacterial activities. To our best knowledge, this is the first report concerning the chemical composition, chemotypic variation, antioxidant, and antimicrobial activities of the essential oils obtained from the aerial parts of А. dracunculus, growing wild in the Varzob region of Tajikistan.

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.

Allium sativum, Rosmarinus officinalis, and Salvia officinalis Essential Oils: A Spiced Shield against Blowflies

Blowflies are known vectors of many foodborne pathogens and unintentional human ingestion of maggots by meat consumption may lead to intestinal myiasis. In fact, the control of insect pests is an important aspect of industrial and home-made food processing and blowflies (Diptera: Calliphoridae), which are among the most important pests involved in the damage of meat products. Most spices, largely used in food preparations and industry, contain essential oils that are toxic and repellent against insects and exert antimicrobial activity. In this study, we assessed the electro-antennographic responses, the oviposition deterrence, the toxicity, and the repellence of the essential oils (EOs) of Allium sativum L., Salvia officinalis L., and Rosmarinus officinalis L. against the blowfly Calliphora vomitoria L. We tested the EOs antibacterial and antifungal properties and the efficacy of an A. sativum EO-charged mist sprayed in the tunnel entryway of a meat processing room to form an olfactive barrier against the entrance of flies. The results showed that the EOs are perceived by female blowfly’ antennae and exert an evident repellent activity against them completely deterring the oviposition for up to 24 h starting from the concentration of 2.5 μL cm⁻² EO. The EOs also exhibited toxic activity by both topical application (LD₅₀ from 0.44 to 1.97 μL insect⁻¹) and fumigation (LC₅₀ from 1.76 to 31.52 μL L⁻¹) against adults of C. vomitoria and were able to exert a clear antimicrobial activity toward pathogens. Lastly, the EO-charged mist was able to reduce by about 40% the presence of Calliphoridae in the meat processing room of a dry-ham factory.

Control of Filth Flies, Cochliomyia macellaria (Diptera: Calliphoridae), Musca domestica (Diptera: Muscidae), and Sarcophaga bullata (Diptera: Sarcophagidae), Using Novel Plant-Derived Methyl Ketones

Filth flies live in close proximity to humans and livestock and transmit pathogens. Current control relies on chemical insecticides, and flies can develop resistance to these insecticides. The public is also interested in natural and safer insecticides. Therefore, alternative pesticides compatible with the synanthropic nature of flies are needed. Four plant aliphatic methyl ketones were evaluated for control of adult house flies, Musca domestica L., blow flies, Cochliomyia macellaria (F.), and gray flesh flies, Sarcophaga bullata (Parker). In sealed petri dish assays, 2-heptanone, 2-octanone, 2-nonanone, and 2-undecanone exhibited fumigant activity against house flies with 24-h LC50s of 6.9, 7.5, 8.0, and 9.2 µg/cm3, respectively. Further research focused on undecanone (a U.S. EPA-registered biopesticide). When tested in larger enclosures at 1.7, 2.3, and 2.8 µg/cm3, undecanone provided 60.4, 82.2, and 94.4% house fly mortality; 56.9, 75.6, and 92.5% flesh fly mortality; and 62.1, 84.5, and 97.9% blow fly mortality, respectively, after a 2-h exposure. In a two-choice behavioral assay with 194.6 µg/cm2 of the test compound on the treatment versus an untreated surface of the same area, the overall mean repellencies for blow flies were 84.7% for undecanone versus 87.6% for N,N-diethyl-meta-toluamide (DEET). For house flies, mean repellencies were 80.7% for undecanone and 84.9% for DEET. The house fly topical LD50 for undecanone was 58.1 µg per fly. Undecanone was far less expensive for filth fly control than the gold standard for insect fumigation, methyl bromide.

Volatile Profile and Physico-Chemical Analysis of Acacia Honey for Geographical Origin and Nutritional Value Determination

Honey composition and color depend greatly on the botanical and geographical origin. Water content, water activity and color of 50 declared acacia samples, collected from three different geographical zones of Romania, together with chromatographic determination of sugar spectrum were analyzed. A number of 79 volatile compounds from the classes of: Alcohols, aldehydes, esters, ketones, sulphur compounds, aliphatic hydrocarbons, nitrogen compounds, carboxylic acids, aromatic acids and ethers were identified by solid-phase micro-extraction and gas-chromatography mass spectrometry. The overall volatile profile and sugar spectrum of the investigated honey samples allow the differentiation of geographical origin for the acacia honey samples subjected to analysis. The statistical models of the chromatic determination, physicochemical parameters and volatile profile was optimal to characterize the honey samples and group them into three geographical origins, even they belong to the same botanical origin.

Synergistic Toxicity of Plant Essential Oils Combined with Pyrethroid Insecticides against Blow Flies and the House Fly

Blow flies (Diptera: Calliphoridae) and the house fly (Diptera: Muscidae) are filth flies of medical importance, and control of their population is needed. As insecticide applications have resulted in fly resistance, and the exploration of plant essential oils (EOs) has increased against filth flies, this study assessed the combination of EOs with pyrethoids to enhance toxic efficacy. The EOs of five effective plants were screened initially against the house fly (Musca domestica L.). Their chemical constituent was performed using gas chromatography-mass spectrometry (GC-MS) analysis. The main components of Boesenbergia rotunda (Zingiberaceae) rhizome, Curcuma longa (Zingiberaceae) rhizome, Citrus hystrix (Rutaceae) fruit peel, Ocimum gratissimum (Lamiaceae) seed, and Zanthoxylum limonella (Rutaceae) fruit were δ-3-caren (35.25%), β-turmerone (51.68%), β-pinene (26.56%), p-cumic aldehyde (58.21%), and dipentene (60.22%), respectively. The screening test revealed that the three most effective plant EOs were from B. rotunda, C. longa and O. gratissimum, which were selected for the combination with two pyrethroid insecticides (permethrin and deltamethrin), in order to enhance their synergistic efficacy against the blow flies, Chrysomya megacephala Fabricius, Chrysomya rufifacies Macquart, and Lucilia cuprina Wiedemann, and the house fly. Synergistic action was presented in almost all of the flies tested with permenthrin/deltamethrin/EOs mixtures. It was interesting that the combination of deltamethrin with three EOs showed a synergistic effect on all of the tested flies. However, an antagonistic effect was observed in C. megacephala and M. domestica treated with permethrin-B. rotunda and C. megacephala treated with permethrin-O. gratissimum. The LD50 of insecticides decreased when combined with plant EOs. This alternative strategy will be helpful in developing a formula for effective fly control management.

Sensory Quality of Essential Oils and Their Synergistic Effect with Diatomaceous Earth, for the Control of Stored Grain Insects

Essential oils (EOs) have gained increasing interest as a low-toxic, eco-friendly alternative to synthetic repellents and insecticides against insect pests. However, they have scarce practical application in the protection of stored grain because of their limited efficacy and their interference with the organoleptic properties of the grain. In this study, we evaluated the olfactory profile of the EOs of Foeniculum vulgare, Pistacia lentiscus, and Ocimum basilicum, and their toxicity against the main stored grain pest Sitophilus granarius. Trained assessors identified O. basilicum and F. vulgare, as more suitable than the P. lentiscus EO for the wheat treatment. In laboratory tests, the most toxic EO was the P. lentiscus (LC₅₀ = 36.36 μL∙kg⁻¹) while, the least toxic, was the F. vulgare one (LC₅₀ = 77.59 μL∙kg⁻¹). The EOs were also tested combined with diatomaceous earths (DEs) showing synergistic effects (co-toxicity coefficient values ranging from 1.36 to 3.35 for O. basilicum and F. vulgare EOs, respectively). Overall, O. basilicum resulted as the best EO for the wheat treatment, considering its insect toxicity and olfactory profile. In real storage conditions, the wheat co-treated with O. basilicum EO and DEs showed a significantly lower mean infestation (1.5 insect kg⁻¹) than the non-treated wheat (7.0 insect kg⁻¹).

Toxicity and oviposition deterrence of essential oils of Clinopodium nubigenum and Lavandula angustifolia against the myiasis-inducing blowfly Lucilia sericata

Cutaneous myiasis is a severe worldwide medical and veterinary issue. In this trial the essential oil (EO) of the Andean medicinal plant species Clinopodium nubigenum (Kunth) Kuntze was evaluated for its bioactivity against the myiasis-inducing blowfly Lucilia sericata (Meigen) (Diptera Calliphoridae) and compared with that of the well-known medicinal plant species Lavandula angustifolia Mill. The EOs were analysed and tested in laboratory for their oviposition deterrence and toxicity against L. sericata adults. The physiology of EO toxicity was evaluated by enzymatic inhibition tests. The antibacterial and antifungal properties of the EOs were tested as well. At 0.8 μL cm^-2, both EOs completely deterred L. sericata oviposition up to 3 hours. After 24 h, the oviposition deterrence was still 82.7% for L. angustifolia and the 89.5% for C. nubigenum. The two EOs were also toxic to eggs and adults of L. sericata. By contact/fumigation, the EOs, the LC₅₀ values against the eggs were 0.07 and 0.48 μL cm^-2 while, by topical application on the adults, LD₅₀ values were 0.278 and 0.393 μL per individual for C. nubigenum and L. angustifolia EOs, respectively. Inhibition of acetylcholine esterase of L. sericata by EOs (IC₅₀ = 67.450 and 79.495 mg L^-1 for C. nubigenum and L. angustifolia, respectively) suggested that the neural sites are targets of the EO toxicity. Finally, the observed antibacterial and antifungal properties of C. nubigenum and L. angustifolia EOs suggest that they could also help prevent secondary infections.

Efficacy of some essential oils on Cephalopina titillator with special concern to nasal myiasis prevalence among camels and its consequent histopathological changes

Nasopharyngeal myiasis is an important high incidence disease among camels in the Middle East and North of Africa caused by Cephalopina titillator (C. titillator) that results in sever economic losses in many camel breeding areas around the world. The current study was conducted to evaluate the efficacy of three essential oils; camphor, ginger and cinnamon oils and their histopathological effects on the 3rd larval instar of C. titillator, with special regard to the prevalence percentage of C. titillator infestation in slaughtered camels at Egyptian abattoirs in addition to investigate histopathological alterations of the infested animal's tissue. This study fulfilled that the prevalence of C. titillator infestation was 35.2% among slaughtered camels during summer season. The three tested essential oils were caused a significant mortality of C. tittilator; however, camphor oil was exhibited greater and quicker insecticidal effect than ginger and cinnamon oils at the same concentration in terms of mortality of the 3rd instar C. tittilator larvae. There was a concentration-dependent effect on the larvae among the tested essential oils. The tested essential oils were caused remarkable histopathological alterations on the treated larval cuticle. The main salient lesions of the examined infested camel's tissue were necrotic and inflammatory alterations associated with cystic dilation of submucosal glands.