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Purpose: The flea Ctenocephalides felis (Siphonaptera: Pulicidae), parasitizes dogs and cats globally, acting as a vector for various pathogens affecting both animals and humans. Growing interest in environmentally friendly, plant-based products prompted this study. The aim of the study was to determine the chemical composition of essential oils (EOs) from Copaifera reticulata, Citrus paradisi, Lavandula hybrida and Salvia sclarea, assessing their insecticidal and repellent properties, determining lethal concentrations (LC50 and LC90), and evaluating residual efficacy in vitro against Ctenocephalides felis felis. Methods: Gas Chromatography with Flame Ionization Detector analyzed EO composition. In vitro tests involved preparing EO solutions at various concentrations. Ten specimens from each life stage (egg, larva, pupa, adult) were used for insecticidal activity assessment. Adulticidal activity was assessed using 10 cm2 filter paper strip, each treated with 0.200 mL of the test solution. Immature stages activities were evaluated using 23.76 cm2 discs of the same filter paper, each treated with 0.470 mL of the test solution. Mortality percentage was calculated using (number of dead insects × 100) / number of incubated insects. Probit analysis calculated LC50 values with a 95% confidence interval. Results: Major EO constituents were β-caryophyllene (EOCR), linalool (EOLH), linalyl acetate (EOSS), and limonene (EOCP). LC50 values were obtained for all stages except for the essential oil of C. paradisi. All oils showed repellent activity at 800 μg/cm2. OECR exhibited greater residual efficacy. Conclusion: Each EO demonstrated superior insecticidal activity against specific C. felis felis stages. [ABSTRACT FROM AUTHOR]

The insecticidal effect of two zeolite formulations was tested on wheat against adults of Lepinotus reticulatus Enderlein, Liposcelis decolor (Pearman), Acarus siro L. and Stegobium paniceum (L.). The zeolites were tested at four dose rates, i.e., 50, 100, 500 and 1000 ppm (mg per kg of wheat). The bioassays were conducted under laboratory conditions. The vials for A. siro were kept at 22°C, 60–70% relative humidity (r.h.), for psocids were kept at 30°C, 75–80% r.h., and for S. paniceum were kept at 26°C, 65–70% r.h., with continuous darkness. The bioassays were conducted in cylindrical glass vials of 20 ml (beetles and psocids) or 4 ml (mites). There were three replicates for each treatment, whereas each bioassay was repeated three times for S. paniceum and A. siro, whereas for psocids species, there were three vials for each treatment. Each vial was filled with 10 g of wheat for psocids and S. paniceum, and 2 g for A. siro. Afterward, ten adults of each species were placed in each vial, with separate series of vials per species, and all vials were kept at the aforementioned conditions. Mortality was determined after 4, 7, and 14 d of exposure for psocids, 3, 7 and 14 d of exposure for S. paniceum and 14 d of exposure for A. siro. From the species tested, L. reticulatus and S. paniceum were by far the most susceptible species, given that mortality reached 100% after 14 days of exposure. In contrast, for the other two species, mortality rate for L. decolor was 27% and for A. siro was 54% after 14 d of exposure at 1000 ppm, indicating that for these species, rapid rebound of their populations is likely to occur. The current study provides data on the toxicity of zeolites against four stored-product insect species, for which the relative data available were scarce. [ABSTRACT FROM AUTHOR]

Nowadays, the insecticidal and acaricidal properties of plant extracts and essential oils (EOs) have been evaluated as an alternative to chemical means. This study aims to assess the insecticidal efficacy of 20 commercial EOs against the adults of Musca domestica Linnaeus (Diptera: Muscidae) by the contact of insects with the residues of EOs at the bottom of glass cups. The dose effects of seven EOs (i.e. Acorus calamus, Allium sativum, Syzygium aromaticum, Cymbopogon citratus, Juniperus communis, Cedrus atlantica, and Foeniculum vulgare) as well as the time effects of exposure to these EOs on the mortality of flies were analyzed by probit analysis. Permethrin (technical substance) was used as a reference insecticide in the positive control and pure acetone served as the negative control. The insecticidal efficacy of the tested EOs decreased in order (based on their lethal dose (LD)50 values): A. calamus > A. sativum > S. aromaticum ≥ C. citratus > J. communis > C. atlantica > F. vulgare. A. calamus EO was the most effective against flies and very fast acting with negligible reversibility of effect. The EOs of A. sativum and S. aromaticum had a significant time-dependent insecticidal effect. The time for 50% insecticidal effect (knockdown and mortality in total) of the A. sativum EO was the greatest among the seven EOs and seven times more in comparison with the positive control. Present results and literature data suggest that the aforesaid plant products could be promising as contact insecticides against adults M. domestica. The difference in the insecticidal properties of A. calamus and A. sativum EOs observed in the current study display the need for various approaches for their future application as insecticides. [ABSTRACT FROM AUTHOR]

The Mediterranean basin thrives in native plant species are able to produce numerous derivatives that can be used for insect pest control. This article provides an up-to-date overview of the most important native plant species commonly found in this region that have a certain insecticidal value in vegetable crops. Regarding the insecticidal activity of extracts from selected native species, results from both laboratory and field experiments will be also presented to highlight the potential of the latter as alternatives to synthetic insecticides. Considering the great diversity in ingredients among the various plant species, it is essential to record and describe the chemical composition of these species, in conjunction with their insecticidal activity against the main insect pests of vegetable crops. The review concludes in underlining the critical points for increasing the effectiveness and consequently the practical use of natural insecticides in crop protection. Moreover, emphasis is given in understanding the importance of the production of standardized and stable natural resource-based insecticides through the development of suitable formulations, such as capsule suspension that protects the active ingredients from environmental degradation and improves their residual activity. [ABSTRACT FROM AUTHOR]

Insecticidal action of plant essential oils has been an area of intensive research in the new millennium, according to a recent bibliometric analysis. Despite this overwhelming research effort, commercialization of bioinsecticides based on essential oils has lagged far behind, although such products have now been used in the USA for over a decade, and in the EU in the last 4–5 years. Recent progress in commercialization of these products is reviewed here. Essential oils and their mono- and sesquiterpenoid constituents are fast-acting neurotoxins in insects, possibly interacting with multiple receptor types. These compounds also display potentially important sublethal behavioural effects in pest insects, including feeding and oviposition deterrence and repellence. Synergy among essential oil terpenoids appears to be a common phenomenon, and a mechanism for this action in rosemary oil has recently been demonstrated. Commercial development of bioinsecticides based on plant essential oils can follow several different pathways producing products with active ingredients differing in their genesis. These include products whose active ingredients consist of (1) a mixture of essential oils; (2) a single essential oil, or a single terpenoid constituent; (3) a blend of terpenoids, synthetically produced, that emulate those in a plant essential oil; and (4) a novel (non-natural) blend of terpenoids obtained from different plant sources. Examples of each of these are provided. [ABSTRACT FROM AUTHOR]

Stilbenes are constitutively accumulated in grape canes at a high concentration of about 10 g kg DW. Some of these compounds have antimicrobial activity and are involved in grapevine defence in leaves and fruits, acting as phytoalexins. In this work, we studied their insecticidal effects against Spodoptera littoralis larvae by using an extract from grapevine canes containing 27% (w/w) of total stilbenes and the major ones isolated from this extract ( E-piceatannol, E-resveratrol, isohopeaphenol, E- ε-viniferin and E-vitisin B). The stilbenes isolated from the grapevine extract did not show any significant antifeedant effect or acute toxicity, but they did cause chronic mortality to the larvae population of an important polyphagous pest, S. littoralis. The tetramer, E-vitisin B, appeared to be the most effective compound with LC and LC values of 134 and 298 µg cm, respectively. Significant synergic relationships were found between some stilbenes, resulting in a significant increase in the insecticidal efficacy of the mixture of these substances. Taken together, these results suggest that grapevine canes are a good source of active substances for the development of botanical insecticides. [ABSTRACT FROM AUTHOR]

Natural sources for novel insecticide molecules hold promise in view of their eco-friendly nature, selectivity, and mammalian safety. Recent progress in understanding the biology of insect olfaction and taste offers new strategies for developing selective pest control agents. We have isolated two natural insecticidal molecules from edible roots of Decalepis hamiltonii named Decalesides I and II, which are novel trisaccharides, highly toxic to household insect pests and stored-product insects. We have experimentally shown that insecticidal activity requires contact with tarsi on the legs but is not toxic orally. The insecticidal activity of molecules is lost by hydrolysis, and various sugars modify toxic response, showing that the insecticidal activity is via gustatory sites on the tarsi. Selective toxicity to insects by virtue of their gustatory site of action and the mammalian safety of the new insecticides is inherent in their chemical structure with 1-4 or 1-1 α linkage that is easily hydrolyzed by digestive enzymes of mammals. Decalesides represent a new chemical class of natural insecticides with a unique mode of action targeting tarsal chemosensory/gustatory system of insects. [ABSTRACT FROM AUTHOR]