Repellent, Insecticidal, and Oviposition Inhibitory Effects of Nicotiana tabacum, Nicotiana rustica, and Nepeta cataria on the Trialeurodes vaporariorum

For the first time, the repellent and insecticidal effects of eucalypt essential oil (Eucalyptus globulus) in its free form and associated with different nanostructures (nanoemulsion and nanocapsules) were investigated against Musca domestica (Diptera: Muscidae) and Haemotobia irritans (Diptera: Muscidae) flies. Specimens of M. domestica were collected, separated into groups (n = 10), treated with aspersion of essential oil of eucalypt in its free (1, 5, and 10%) and nanostructured (nanoemulsion or nanoencapsulated at 1, 3, and 5%, respectively) forms. The determination of the insecticidal effect was performed by counting the number of dead flies at intervals of 30, 60, 120, 360 and 750 min after oil aspersion. E. globulus essential oil showed insecticidal effect against M. domestica at concentrations of 1 and 5%. Eucalypt essential oil (10%) caused 100% mortality of M. domestica after 750 min of the treatment. Nanocapsules (3 and 5%) showed efficacy by reducing the number of flies. On the other hand, nanoemulsion did not show insecticidal effect. The repellent action of E. globulus concentrations of 5% was tested against H. irritans on naturally infested cows. The repellent action against H. irritans was verified soon after pulverization. After 24 h, a significant reduction on horn flies' population (83.33 and 66.66%) was observed using free and nanoencapsulated forms tested, respectively. E. globulus essential oil demonstrated insecticidal and repellent effects against M. domestica and H. irritans flies.

The red flour beetle (Tribolium castaneum) is a major pest causing significant damage to stored grains, leading to substantial economic losses. This study evaluated the repellent and insecticidal effects of red pepper (Capsicum frutescens), moringa (Moringa oleifera), and eucalyptus (Eucalyptus camaldulensis) powders against T. castaneum larvae and adults. Plant materials were dried, ground, and applied to crushed rice grains at concentrations of 1%, 2.5%, and 5%. The repellent effect was assessed by recording the number of insects leaving treated grains over five days, while the insecticidal effect was determined by calculating the corrected mortality percentage after seven days of treatment. Results showed that eucalyptus powder at 5% concentration had the highest repellent effect on larvae, with an overall repellence rate of 46.01%. Red pepper powder at 5% concentration was most effective in repelling adults, with an average repellence rate of 71.46%. Moringa powder at 5% concentration exhibited the highest insecticidal effect, causing 66.67% mortality in both larvae and adults. The efficacy of plant powders increased with higher concentrations. The repellent and insecticidal effects of these plant powders may be attributed to their volatile compounds, secondary metabolites, and physical properties. This study demonstrates the potential of using red pepper, moringa, and eucalyptus powders as eco-friendly alternatives to synthetic insecticides for protecting stored rice grains from T. castaneum infestation. Further research is needed to evaluate the effectiveness of these plant powders in protecting other stored crops from various storage pests.

The red flour beetle (Tribolium castaneum) is a major pest causing significant damage to stored grains, leading to substantial economic losses. This study evaluated the repellent and insecticidal effects of red pepper (Capsicum frutescens), moringa (Moringa oleifera), and eucalyptus (Eucalyptus camaldulensis) powders against T. castaneum larvae and adults. Plant materials were dried, ground, and applied to crushed rice grains at concentrations of 1%, 2.5%, and 5%. The repellent effect was assessed by recording the number of insects leaving treated grains over five days, while the insecticidal effect was determined by calculating the corrected mortality percentage after seven days of treatment. Results showed that eucalyptus powder at 5% concentration had the highest repellent effect on larvae, with an overall repellence rate of 46.01%. Red pepper powder at 5% concentration was most effective in repelling adults, with an average repellence rate of 71.46%. Moringa powder at 5% concentration exhibited the highest insecticidal effect, causing 66.67% mortality in both larvae and adults. The efficacy of plant powders increased with higher concentrations. The repellent and insecticidal effects of these plant powders may be attributed to their volatile compounds, secondary metabolites, and physical properties. This study demonstrates the potential of using red pepper, moringa, and eucalyptus powders as eco-friendly alternatives to synthetic insecticides for protecting stored rice grains from T. castaneum infestation. Further research is needed to evaluate the effectiveness of these plant powders in protecting other stored crops from various storage pests.

The influences of different plants on herbivores have recently attracted research interest; however, little is known regarding the effects of wild, local and cultivated varieties of the same plant from the same origin on herbivores. This study aimed to examine the effects of different tobacco varieties from the same origin on the oviposition preference and offspring performance of Spodoptera litura. We selected two wild ('Bishan wild tobacco' and 'Badan wild tobacco'), two local ('Liangqiao sun-cured tobacco' and 'Shuangguan sun-cured tobacco') and two cultivated ('Xiangyan No. 5' and 'Cunsanpi') tobacco varieties from Hunan Province, China. We found that female S. litura varied in oviposition preferences across the tobacco varieties. They preferred to lay eggs on the cultivated varieties, followed by the local varieties, with the wild varieties being the least preferred. Furthermore, different tobacco varieties significantly influenced the life history parameters of S. litura. Survival rate, pupal weight, emergence rate and adult dry weight decreased in the following order: cultivated varieties > local varieties > wild varieties. Conversely, the pupal stage and development period decreased in the following order: wild varieties > local varieties > cultivated varieties. Therefore, we conclude that wild tobacco varieties have higher resistance to S. litura than cultivated and local varieties, reflecting the evolutionary advantages of wild tobacco varieties.

Catnip (Nepeta cataria) is known for its pseudo-narcotic effects on cats. Recently, it has been reported as an effective mosquito repellent against several Aedes and Culex species, both topically and spatially. Our laboratory bioassays showed that catnip essential oil (at a dosage of 20 mg) resulted in average repellency rates of 96% against stable flies, Stomoxys calcitrans (L.) and 79% against houseflies, Musca domestica (L.), respectively. This finding suggested that the application of repellent could be used as part of filth fly management. Further evaluations of catnip oil toxicity were conducted to provide a broad-spectrum safety profile of catnip oil use as a potential biting and nuisance insect repellent in urban settings. Acute oral, dermal, inhalation, primary dermal and eye irritation toxicity tests were performed. The acute oral LD(50) of catnip oil was found to be 3160 mg/kg body weight (BW) and 2710 mg/kg BW in female and male rats, respectively. The acute dermal LD50 was > 5000 mg/kg BW. The acute inhalation LD50 was observed to be > 10,000 mg/m3. Primary skin irritation tested on New Zealand white rabbits showed that catnip oil is a moderate irritant. Catnip oil was classified as practically non-irritating to the eye. In comparison with other U.S. Environmental Protection Agency-approved mosquito repellents (DEET, picaridin and p-menthane-3,8-diol), catnip oil can be considered as a relatively safe repellent, which may cause minor skin irritation.

This study evaluated the repellent efficacy of catnip (Nepeta cataria) essential oil and its potential for development into safe topical products. Pure catnip oil was first tested against Aedes aegypti using the Arm-in-Cage (AIC) method, providing complete protection (CPT) for 220.00 ± 6.32 minutes, thereby confirming its strong intrinsic repellent activity. To create user-appropriate products, a 20% dilution of catnip oil was incorporated into two topical prototypes: a spray and a gel. Both were assessed using the AIC method, with repellency recorded at 30-minute intervals over a 3-hour exposure period. The spray demonstrated a mean repellency of 84.70 ± 2.68%, while the gel maintained a slightly higher repellency of 91.83 ± 2.09%, with CPTs of 110.00 ± 20.00 and 130.00 ± 14.83 minutes, respectively. Skin patch testing confirmed that both formulations were well tolerated, with no irritation observed. To the best of our knowledge, this is the first study to evaluate catnip essential oil formulated into topical spray and gel prototypes and to assess both their repellency and skin tolerability in human volunteers. These findings indicate that catnip oil is an effective natural mosquito repellent and that 20% spray and gel formulations can provide safe, reliable protection against Ae. aegypti.

Curcuma longa has well-known insecticidal and repellent effects on insect pests, but its impact on Trichoplusia ni is unknown. In this study, the compound ar-turmerone, extracted and purified from C. longa rhizomes, was identified, and its insecticidal effects, along with turmeric powder, curcuminoid pigments and crude essential oil were evaluated against this important agricultural pest. The role of natural (sesamol and piperonal) and synthetic [piperonyl butoxide (PBO)] synergists under laboratory and greenhouse conditions were also evaluated. The concentration of ar-turmerone in C. longa rhizomes harvested was 0.32% (dwt). Turmeric powder and its derivatives caused 10–20% mortality in third instar T. ni at a very low dose (10 μg/larva). Addition of PBO increased toxicity of turmeric powder and its derivatives (90–97% mortality) in most binary combinations (5 μg of turmeric powder or its derivatives +5 μg of PBO), but neither piperonal nor sesamol were active as synergists. The compound ar-turmerone alone and the combination with PBO reduced larval weight on treated Brassica oleracea in the laboratory and in greenhouse experiments, compared with the negative control. The compound ar-turmerone could be used as a low cost botanical insecticide for integrated management of cabbage looper in vegetable production.

The spotted wing drosophila (SWD), Drosophila suzukii Matsumura (Diptera: Drosophilidae), is an invasive polyphagous pest of soft-skinned fruit that has started to threaten small fruit production in Europe since 2008. High reproductive capacity, short generation time, and difficulties in visualizing early damage contribute to its rapid spread. Currently, the control strategy against D. suzukii mostly relies on treatment with synthetic insecticides. Keeping in mind that this pest causes the greatest damage during the harvesting period, control using chemicals is not recommended due to the increased risk of high pesticide residue levels in the fruit. With the aim of reducing the use of insecticides, there is a need for developing an environmentally safer way of control. Alternative solutions could rely on the use of essential oils (EOs), which can be used in conventional and organic production systems. Four essential oils, geranium (Pelargonium graveolens), dill (Anethum graveolens), Scots pine (Pinus sylvestris), and bergamot (Citrus bergamia), were assessed for their insecticidal effects using four different tests (contact toxicity, fumigant-contact toxicity, repellent effect, and multiple-choice tests). The EOs applied were dissolved in acetone at three different concentrations. The most promising one was the geranium essential oil, which had the best effect in all conducted tests, even at the lowest applied concentration. Geranium oil caused very high mortality (95%), even at the lowest concentration applied, after 24 h in the fumigant-contact test, and it caused a mortality of over 85% in the contact test. It was also noticed that geranium demonstrated a deterrent effect by repelling females from laying eggs for four days after at the lowest applied concentration. Scots pine and dill EOs have moderate to strong effects in most tests. The mortality of 100% was achieved for the highest applied concentration in the fumigant-contact and contact tests. Bergamot EO did not have any significant insecticidal activity. Geranium, Scots pine, and dill have great potential to be used as an environmentally friendly way of controlling D. suzukii as they exhibit deterrent, repellent, and insecticidal effects.

Objetivo. Debido a la mayor resistencia parásita, hay una necesidad de explorar insecticidas alternativos, incluidos los productos naturales, tales como aceites esenciales. En este sentido, el objetivo de este estudio fue evaluar, para el primer equipo, el efecto insecticida y repelente de Cinnamomum zeylanicum (formas libres y nanoemulsión) in vitro e in vivo. Materiales y métodos. Para ello, el efecto insecticida de la forma libre se ensayó a 1.0, 5.0 y 10%, mientras que la forma nanoemulsión se ensayó a 0.5, 1.0 y 5.0% frente a las moscas domésticas adultas, Musca domestica. Para la validación de la prueba, las moscas fueron rociados con el diluyente (agua y triton 10%) y con nanoemulsión en blanco (sin aceite esencial de C. zeylanicum). También, fueron realizados pruebas in vivo usando vacas naturalmente infestadas con Haemotobia irritans. Resultados. Los resultados demostraron que el aceite de canela (10%) y la nanoemulsión (5%) fueron 100% eficaz contra M. domestica después de 90 minutos de exposición. El efecto repelente se ensayó in vivo usando 5% de aceite de canela en vacas Holstein, naturalmente infestados por Haemotobia irritans. Se contaron las moscas a las 0, 1, 2, 3, 9 y 24 h después del tratamiento el aceite de canela. Se verificó disminución significativa (p<0.05) en el número de moscas vivas de vacas canela pulverizada en todo momento. Conclusiones. En base a estos resultados, C. zeylanicum mostró un efecto insecticida (in vitro) contra las moscas domésticas y efecto repelente (in vivo) contra la mosca de los cuernos.

Cyclodextrin inclusion complexes have been successfully used to encapsulate essential oils, improving their physicochemical properties and pharmacological effects. Besides being well-known for its effects on cats and other felines, catnip (Nepeta cataria) essential oil demonstrates repellency against blood-feeding pests such as mosquitoes. This study evaluates the tick repellency of catnip oil alone and encapsulated in β-cyclodextrin, prepared using the co-precipitation method at a 1:1 molar ratio. The physicochemical properties of this inclusion complex were characterized using GC-FID for encapsulation efficiency and yield and SPME/GC-MS for volatile emission. Qualitative assessment of complex formation was done by UV-Vis, FT-IR, 1H NMR, and SEM analyses. Catnip oil at 5% (v/v) demonstrated significant tick repellency over time, being comparable to DEET as used in commercial products. The prepared [catnip: β-CD] inclusion complex exerted significant tick repellency at lower concentration of the essential oil (equivalent of 1% v/v). The inclusion complex showed that the release of the active ingredient was consistent after 6 h, which could improve the effective repellent duration. These results demonstrated the effective tick repellent activity of catnip essential oil and the successful synthesis of the inclusion complex, suggesting that β-CDs are promising carriers to improve catnip oil properties and to expand its use in repellent formulations for tick management.

Catnip (Nepeta cataria L.), a popular aromatic herb used as a traditional medicine is more widely recognized for its use in the pet toy industry due to the behavioral effects it elicits on cats and other felids. A major interest in catnip is also due to its repellent activity against arthropods. Essential oil of catnip is an effective repellent against several species of mosquitoes, flies, ticks, mites, and other disease vectors, with results comparable to DEET. Both the repellency to arthropods and the characteristic effects on cats are mainly attributed to nepetalactone, a bicyclic oxygenated monoterpene in the essential oil of catnip. While catnip is grown as a garden herb and in the open field for dried biomass and essential oil, the lack of improved genetic materials makes it difficult for North American growers to expand production and ensure adequate product supply. The present chapter provides an overview of the recent advances in breeding, biochemistry, production systems, biological activities and potential new uses of N. cataria and other Nepeta species in North America.

Catnip (Nepeta cataria, L.) has well-documented applications in arthropod repellency because of its bioactive iridoids. Long-term stability of nepetalactones and other iridoids in N. cataria are needed to develop as effective pest repellents. The present work intends to measure iridoid concentration over time in biomass, plant extracts, and extract solution while identifying degradative byproducts under different storage conditions. Samples of desiccated biomass, ethanol extract, and extract in ethanol solution were stored in ambient light or darkness. Through UHPLC-QTOF/MS or UHPLC-QQQ/MS, the concentration of Z,E-nepetalactone, E,Z-nepetalactone, nepetalic acid, and dihydronepetalactone were examined over 2years and statistically analyzed for determination of best storage practices. Degradation kinetics were applied to each analyte using graphical estimation. With targeted formula searching, degradative byproducts were identified and quantified. Light exposure caused significant decreases in E,Z-nepetalactone concentration in all sample types, while having no effect on Z,E-nepetalactone as it decayed more rapidly. Extract samples lost nepetalactone content faster than biomass or extract solution. Dihydronepetalactone levels were low, but never declined over 2years. Nepetalic acid increased over some periods, depending on sample type, indicating a relationship between the acid and nepetalactone. Four degradative byproducts-nepetonic acid, dehydronepetalactone, an anhydride, and an ethanolic ester-were identified, with variable responses to light exposure. Protecting catnip products from light is necessary to preserve nepetalactones, and a discernable difference in nepetalactone isomer stability was discovered. Identifying Nepeta chemotypes rich in dihydronepetalactone may provide more resilient botanicals as starting materials for processing.

The paper comprises of the chemistry and the application of some medicinal plant products which have been used as insecticides and insect repellents also. Plants play an important role in every aspect of human activity even in the conservation of our heritage. Over the past few years, there has been growing worldwide concern about the adverse effects of certain chemical pesticides, natural substances being integral part of biosphere are less disruptive to ecological balance; hence, several plants and their products have been experimented against museum insects. At present there are no dearth of modern chemical pesticides and repellents for the safe upkeep of museum objects. The advent of technology has also given rise to greater concerns of preservation of museum objects by adopting modern technologies. Still the uses of herbal remedies for preservation are in vogue, as these have their own merits. Unfortunately, these recipes are being lost as advertising to use modern chemicals increases. It is not old fashioned to use natural pesticides—rather it is a smart use of the natural resources that are readily available. In this context an attempt has been made to summarize the effectiveness of various Indian herbal pesticides and insect repellents which are being used by different organizations or could be used by the organizations to seize the growth of insect infestation in the different museums. This present investigation deals with the application of leaves, bark, seeds, wood and roots of different medicinal plants having toxic effects on different museum pests. Natural pesticides usually take longer to work than synthetic pesticides. Thus, it is important to apply them as soon as the objects show evidence of pests. Insects are killed either by contact or by ingestion of the insecticides. Some insecticides only repel the insects by a strong odour, they are known as insect repellent. The effectiveness of insecticides and repellents varies with the active ingredient(s), the concentration and the target species. Finally, the paper spells out the preparation processes of pesticides from plants.

Наведено результати досліджень із вивчення еколого-біологічних особливостей лопуха великого Arctium lappa L. та котячої м'яти справжньої Nepeta cataria L. в умовах ботанічного розсадника Житомирського національного агроекологічного університету. Мета роботи полягала у вивченні інтродукції, шляхів підвищення біологічної продуктивності досліджуваних рослин в умовах Полісся України. На основі багаторічних досліджень вперше вивчено можливість і способи одночасного вирощування лопуха великого на листок і корінь у підзимніх і ранньовесняних поточних і перехідних посівах другого року вегетації. Під час вирощування Arctium lappa L. на корені запропоновано однорічний термін вирощування культури із збиранням сировини у другій половині вересня. Підрізування головного кореня на глибині 15–20 см у фазі росту другого-третього справжнього листка знижувало біологічну продуктивність кореневої системи на 10–15 %. В умовах Полісся України доцільно вирощувати котячу м'яту справжню як дворічну культуру. Максимальна врожайність повітряно сухої сировини формується у котячої м'яти справжньої у фазі масового цвітіння і залежно від погодних умов у середньому за роками досліджень становить у рослин першого року життя 185,0 г/м2, у рослин другого року життя – 367,0 г/м2. Вміст ефірної олії у повітряно сухій сировині характеризується невисокими показниками. У середньому за роки досліджень у рослин котячої м'яти справжньої першого року життя 0,07 %, другого року життя – 0,14 %.

BackgroundChemical control is generally used against aphids. The harmful effects of the chemicals used in the control on the environment and human health have contributed to the development of alternative control methods. The main objective of this study was to determine chemical composition of Mentha longifolia L. essential oil obtained from spontaneous plants in Algeria, investigate repellent and con-tact toxicity effect on Aphis craccivora Koch control, and assess the impacts of essential oil on development, survival and reproduction of A. craccivora.ResultsThe essential oil showed a concentration dependent significant toxic and repellent effects. The highest effect was recorded for 8 μl/ml concentration of essential oil. The repellent effect and mortality rate in 8 μl/ml concentration were 84.37 and 80.66%, respectively. The values of LC50 and LC90 were 1.848 and 26.782 μl/ml, respectively. The effect of essential oil on immature period, adult longevity, natal period, survival, and fecundity was statistically significant (p < 0.05).ConclusionsThe findings in this study showed that the essential oil of M. longifolia harvested in the Tamanrasset region of Algeria has a toxic effect on A. craccivora, and can have a potential to be used as an insecticide to control A. craccivora. The use of environmentally friendly bioinsecticide will enable effective management of A. craccivora.Graphical