41 research outputs found
Detection of Adulteration in Argan Oil by Using an Electronic Nose and a Voltammetric Electronic Tongue
Adulteration detection of argan oil is one of the main aspects of its quality control. Following recent fraud scandals, it is mandatory to ensure product quality and customer protection. The aim of this study is to detect the percentages of adulteration of argan oil with sunflower oil by using the combination of a voltammetric e-tongue and an e-nose based on metal oxide semiconductor sensors and pattern recognition techniques. Data analysis is performed by three pattern recognition methods: principal component analysis (PCA), discriminant factor analysis (DFA), and support vector machines (SVMs). Excellent results were obtained in the differentiation between unadulterated and adulterated argan oil with sunflower one. To the best of our knowledge, this is the first attempt to demonstrate whether the combined e-nose and e-tongue technologies could be successfully applied to the detection of adulteration of argan oil
Recent advances toward the sustainable management of invasive Xylosandrus ambrosia beetles
We provide an overview of both traditional and innovative control tools for management of three Xylosandrus ambrosia beetles (Coleoptera: Curculionidae: Scolytinae), invasive species with a history of damage in forests, nurseries, orchards and urban areas. Xylosandrus compactus, X. crassiusculus and X. germanus are native to Asia, and currently established in several countries around the globe. Adult females bore galleries into the plant xylem inoculating mutualistic ambrosia fungi that serve as food source for the developing progeny. Tunneling activity results in chewed wood extrusion from entry holes, sap outflow, foliage wilting followed by canopy dieback, and branch and trunk necrosis. Maintaining plant health by reducing physiological stress is the first recommendation for long-term control. Baited traps, ethanol-treated bolts, trap logs and trap trees of selected species can be used to monitor Xylosandrus species. Conventional pest control methods are mostly ineffective against Xylosandrus beetles because of the pests’ broad host range and rapid spread. Due to challenges with conventional control, more innovative control approaches are being tested, such as the optimization of the push–pull strategy based on specific attractant and repellent combinations, or the use of insecticide-treated netting. Biological control based on the release of entomopathogenic and mycoparasitic fungi, as well as the use of antagonistic bacteria, has yielded promising results. However, these technologies still require validation in real field conditions. Overall, we suggest that management efforts should primarily focus on reducing plant stress and potentially be combined with a multi-faceted approach for controlling Xylosandrus damage
Recent trends in management strategies for two major maize borers: Ostrinia nubilalis and Sesamia nonagrioides
23 p.-2 tab.Stem borers (Lepidoptera) are common cereal pests. In many parts of the world, the species Ostrinia nubilalis and Sesamia nonagrioides stand out as important insect pests of economically important crops such as maize. Their management relied mainly on transgenic host plant resistance over the last 25 years. Technologies based on the insecticidal properties of Bacillus thuringiensis-derived proteins allowed widespread pest population suppression, especially for O. nubilalis. However, the recent discovery of Bt resistance, which has revitalized interest in both pests’ biology and management, may jeopardize the effectiveness of such transgenic technologies. Historical information on O. nubilalis bionomy may need to be reassessed in light of changing climate conditions and changing agricultural practices, as well as increased production of alternate host crops across its distribution range. The current paper examines the bioecology and historical research that has been conducted to manage these two important maize-boring pests.N
Integrated pest management of Tuta absoluta: practical implementations across different world regions
The South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), has invaded most Afro-Eurasian countries and is threatening worldwide tomato production. Various strategies have been developed and implemented to manage this pest. Here, we present a timely review on the up-to-date development and practical implementation of integrated pest management (IPM) programs for tomato crops across different world regions infested by T. absoluta. While insecticide resistance is a growing concern, biological control via releasing or conserving arthropod natural enemies and sex pheromone-based biotechnical control are the most successful management practices. Agronomic control-related research is an emerging area where the soil fertilization and/or irrigation, as well as breeding of resistant cultivars, has the potential to enhance IPM effectiveness. Grower survey responses in the native areas (i.e., South America), early-invaded areas (i.e., first report between 2006 and 2012) and newly invaded areas (i.e., first report after 2012) showed that the control programs evolved along with the areas and time since invasion. Growers in the early-invaded areas shifted more rapidly from chemical control to biological control compared to those from the native area. In all concerned regions, the pest control failure risk following chemical insecticide applications and the high cost associated with either biological or biotechnical control methods have been the greatest concerns for growers. The information gathered from the native and/or early-invaded areas may help achieve a more effective management in newly invaded areas. Lastly, researchers are expected to break the bottlenecks of some key issues that would enable lowering application cost of novel biorational alternative management options
Bioactivity of Essential Oil from <i>Citrus aurantium</i> Peel against the Pulse Beetle <i>Callosbruchus maculatus</i> F. on Chickpea
Plant essential oils (EOs) and their active compounds are recognized as sustainable tools for the management of arthropod pests. The bitter orange, Citrus aurantium L. (Rutaceae), is a widespread tree in the Mediterranean region that is used especially as a rootstock for other Citrus. Although most of this plant’s parts are accredited with medicinal properties, its fruits are not consumable and generally considered as non-valued waste. The aim of this work was to assess the potential use of the EO extracted by hydrodistillation from C. aurantium peel in the fumigation of chickpea seeds against Calloosbruchus maculatus. Analysis of EO of the bitter orange peel by gas chromatography coupled with a mass spectrometer (GC-MS) identified twenty-two compounds with limonene as the major component (86%). EOs of C. aurantium peel exerted toxic effects, in a concentration-dependent manner, on eggs (LC50 = 62.7 µL/L air), larval stages inside the seed (LC50 = 62.8 µL/L air), and adults (females: LC50 = 148 μL/L air and males: LC50 = 109 µL/L air). The C. aurantium EO also negatively affected the biological and demographic performances of the weevil compared to the untreated control. Fecundity and the number of emerged adults were reduced by more than 57 and 71, respectively, while the net reproduction rate and the intrinsic rate of increase were respectively decreased by over 71% and 37%, resulting in the total extinction of the pest at a concentration equal to 100 µL/L air. Our findings suggest the possible valorization of bitter orange peel by using them as a source of bioinsecticide to be integrated within sustainable programs for the management of stored product pests. Further studies are needed to verify similar uses of essential oils extracted from solid wastes from citrus-processing industries
Drosophila suzukii (Diptera: Drosophilidae) arrives at Minas Gerais state, a main strawberry production region in Brazil
Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) was first collected in Minas Gerais State, Brazil, in Mar 2016, in the municipality of Ervália, from an organic strawberry field. In Brazil, this pest was first recorded in the southernmost region, in Rio Grande do Sul and Santa Catarina states. Drosophila suzukii's arrival to Minas Gerais State, about 1,500 km north from its first record, should alarm the growers, the research community, and the authorities, because this region is the main strawberry production region in Brazil and is now susceptible to large increases in production losses caused by this invasive species. The lack of alternative effective management tools for D. suzukii, besides traditional chemical sprays, makes this pest an important area of study. Future research should focus on finding strategies that match with different local growing systems and edaphoclimatic conditions.Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) foi primeiramente coletada no estado de Minas Gerais em Março de 2016, no município de Ervália, em uma produção orgânica de morangos. No Brasil, esta praga foi primeiramente encontrada na região do extremo sul, nos estados do Rio Grande do Sul e Santa Catarina. A chegada de D. suzukii à Minas Gerais, aproximadamente 1.500 km ao norte do seu primeiro registro, deve alertar os produtores, a comunidade cientifica e autoridades, já que esta região é a principal região produtora de morangos do Brasil e agora está suscetível à aumentos nas perdas da produção causadas por essa espécie invasiva. A falta de ferramentas de manejo efetivas alternativas para D. suzukii, além do controle químico tradicional, torna esta praga um importante objeto de estudo. Pesquisas futuras deverão focar em encontrar ferramentas que combinem com diferentes sistemas de produção e condições edafoclimáticas locais
Pyrethroid resistance is associated with a kdr‐type mutation (L1014F) in the potato tuber moth Tecia solanivora
The Guatemalan potato tuber moth, Tecia solanivora, has been the most important pest species in Hispanico‐American potato fields since its first record on potatoes in 1956 in Guatemala. This insect pest has been spreading to other parts of the world, including the Canary Islands in Europe. Tuber moth control relies heavily on the use of insecticides, including pyrethroids. Here, we assessed the likelihood of control failures and performed concentration–response bioassays in five Colombian strains of T. solanivora to evaluate their susceptibilities to the pyrethroid permethrin. Evidence of control failures was observed in four strains tested, which exhibited moderate resistance levels (i.e. ranging from 5.4‐ to 24.4‐fold). However, no spatial dependence was observed between the permethrin LC50 values and the geographic distances among the tuber moth strains. In order to evaluate whether permethrin resistance was mediated by potential mutations in the para‐type sodium channels of T. solanivora, the IIS4–IIS6 region of the para gene was PCR amplified and sequenced from the five strains tested. As demonstrated across a range of different arthropod species that exhibited knockdown resistance (kdr), we observed a single point substitution (L1014F) at high frequencies in the para gene of all four resistant strains. This is the first identification of a target‐site‐alteration‐based resistance in the Guatemalan potato tuber moth T. solanivora, which is widespread and exhibits high frequencies among geographically distant strains, indicating that pyrethroids are probably becoming ineffective for the control of this pest species
Toxicity to and egg‐laying avoidance of Drosophila suzukii (Diptera: Drosophilidae) caused by an old alternative inorganic insecticide preparation
The application of synthetic insecticides remains the most used tool for the management of spotted‐wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae). However, management of this pest in the organic production of soft‐skinned fruits is a complex task due to the restricted number of registered products. Here, we assess the toxicity of lime sulfur and evaluate whether lime sulfur‐treated strawberry plants affected the oviposition and development of D. suzukii. Lime sulfur exhibited adequate toxicity to D. suzukii (LC50 = 26.6 mL L−1) without phytotoxicity to strawberry plants. When D. suzukii females were exposed to lime sulfur‐treated plants in no‐choice bioassays, oviposition was significantly (t‐test, P < 0.05) reduced compared with that on untreated plants. In free‐choice bioassays, D. suzukii females laid significantly (paired t‐test, P < 0.05) more eggs on untreated plants. Furthermore, in the free‐choice bioassays, immature development was slower for adults that originated from eggs laid on lime sulfur‐treated plants than from those laid on untreated plants. Lime sulfur showed adequate control and, therefore, has potential for use as a management tool against D. suzukii infestations in organic production systems. This old, alternative insecticide preparation not only caused adult fly mortality, but also reduced the number of eggs laid on lime sulfur‐treated plants
Toxicity to and egg‐laying avoidance of Drosophila suzukii (Diptera: Drosophilidae) caused by an old alternative inorganic insecticide preparation
The application of synthetic insecticides remains the most used tool for the management of spotted‐wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae). However, management of this pest in the organic production of soft‐skinned fruits is a complex task due to the restricted number of registered products. Here, we assess the toxicity of lime sulfur and evaluate whether lime sulfur‐treated strawberry plants affected the oviposition and development of D. suzukii. Lime sulfur exhibited adequate toxicity to D. suzukii (LC50 = 26.6 mL L−1) without phytotoxicity to strawberry plants. When D. suzukii females were exposed to lime sulfur‐treated plants in no‐choice bioassays, oviposition was significantly (t‐test, P < 0.05) reduced compared with that on untreated plants. In free‐choice bioassays, D. suzukii females laid significantly (paired t‐test, P < 0.05) more eggs on untreated plants. Furthermore, in the free‐choice bioassays, immature development was slower for adults that originated from eggs laid on lime sulfur‐treated plants than from those laid on untreated plants. Lime sulfur showed adequate control and, therefore, has potential for use as a management tool against D. suzukii infestations in organic production systems. This old, alternative insecticide preparation not only caused adult fly mortality, but also reduced the number of eggs laid on lime sulfur‐treated plants
Low Concentrations of Eucalyptus Essential Oil Induce Age, Sex, and Mating Status-Dependent Stimulatory Responses in Drosophila suzukii
Plant-extracted essential oils are generally suggested as potential sources for alternatives to synthetic insecticides in insect pest control strategies. The increased interest in the use of essential oils derives from the generalized perception of their safety for the environment, human health, and non-target organisms as well as a lower risk of resistance development. However, studies on essential oils have largely focused on their activity on targeted insect pests while overlooking their potential unintended effects on insect biological and reproductive traits, especially with sublethal exposures. Here, we first determined the toxicity of Eucalyptus globulus essential oil to adults of Drosophila suzukii and assessed the effects of low concentrations (i.e., LC5 and LC20) in old (5–7 days) and mated flies. Subsequently, we assessed longevity and fecundity in newly emerged virgin flies from four couples’ combinations: unexposed couples, exposed females, exposed males, and exposed couples to the low concentration LC20. Our results show that eucalyptus essential oil has good insecticidal activity against adults of D. suzukii. However, compared to untreated flies, the exposure to low concentrations enhanced the females’ fecundity only when both old and mated female and male flies were exposed, while the females’ but not males’ life span was extended only in couples where newly emerged virgin females were exposed. Our findings suggest that although the eucalyptus essential oil may be a good control alternative for adult D. suzukii, its age-, sex-, and mating status-dependent stimulatory responses mediated by exposure to low concentrations need to be considered and further investigated