Search Results (39)

Contact insecticides are classified into two categories: as grain protectants, which are applied directly on grains, and as surface treatments, which are applied on cracks and crevices. The aim of this study was to evaluate the long-term residual efficacy of these insecticides across different surfaces and target species. Thus, we investigated the efficacy of three insecticidal formulations, spinosad, alpha-cypermethrin, and pirimiphos-methyl against stored product beetles on different surfaces (concrete, metallic, plastic, and ceramic). Adults of Tribolium castaneum, Sitophilus granarius, and Lasioderma serricorne were used in the experiments. Bioassays were carried out during a six-month period, with mortality measured after 3, 7, 14, and 21 days after exposure. Among the different insecticides tested, spinosad was the least effective against T. castaneum, especially on concrete, where mortality had decreased to zero by Month 2, whereas in most of the cases, close to 100% was recorded. Regarding S. granarius, pirimiphos-methyl and spinosad remained effective on ceramic and metallic surfaces for a six-month period, whereas alpha-cypermethrin had the lowest mortality rate. For L. serricorne, spinosad caused high mortality levels, whereas pirimiphos-methyl was the least effective after Month 4. Based on our finding, among the tested insecticides, spinosad had the long-term residual effect on stored product protection. Full article

Stored grain pests cause significant economic losses during cereal grain storage. Insecticides have long been central to pest control; however, growing concerns over resistance, environmental harm, and human health demand alternative strategies. Diatomaceous earth (DE) treatments are a safe, eco-friendly alternative to insecticides, although their efficacy depends on the temperature, humidity, dose, and insect species. This study assessed the insecticidal effects of two natively-sourced raw (Ankara and Aydin) and one commercial (Silico-Sec) DE treatments against the key pest species Rhyzopertha dominica (F.) and Sitophilus granarius (L.) on stored wheat. Five doses (0, 250, 500, 750, and 1000 ppm) of each DE treatment were tested under two temperatures (25 °C and 30 °C) and two humidity levels (40% and 60%). Mortality was assessed at 7, 14, and 21 days after treatment (DAT). All DE treatments caused higher mortality in S. granarius than R. dominica. The highest mortality occurred in S. granarius at 30 °C and 40% RH with the highest dose. Aydin DE was most effective, but did not reach 100% mortality in S. granarius by 21 DAT. In contrast, it caused 100% mortality in R. dominica under the same conditions. There was no F₁ progeny produced by surviving individuals of both species. Given the similarity of the environmental conditions to the optimal conditions for DE efficacy present in Turkish storage facilities, natively sourced Aydin DE is a promising control option. Full article

This study examines the phytochemical composition, antioxidant, antifungal, and insecticidal properties of Origanum syriacum (Syrian oregano plant) and Cymbopogon wimterianus (Java citronella plant) extracts. Their potential applications in food preservation and pest control are explored based on their bioactive properties. The phytochemical screening indicated a rich presence of secondary metabolites in the extract. The hydrodistillation of plant leaves resulted in an extraction yield of 4.3% Syrian oregano essential oil. The major component of the essential oil was carvacrol (79.30%). The Syrian oregano ethanolic extract contained 110.674 ± 1.842 mg GAE/g total phenols and 52.57 ± 0.086 mg RE/g total flavonoids, and exhibited a high antioxidant activity with a half-maximal inhibitory concentration (IC₅₀) equal to 168.28 μg/mL. Flatbread was prepared with additions of Syrian oregano and Java citronella powders, followed by analysis of moisture content, visual appearance, and sensory characteristics. The results showed that the powders of Syrian oregano and Java citronella have promising food preservative effects. These findings were supported by a significant decrease in fungal growth in several samples and a shelf life extension of one day. The inclusion of a 2% mixture of Syrian oregano and Java citronella powder in the flatbread resulted in the sample receiving the highest overall acceptability mark from consumers, while also extending its shelf life. To assess the insecticidal activity, weevils (Sitophilus granarius L.) were exposed to Syrian oregano and Java citronella essential oils. The insecticidal activity was at its peak when Syrian oregano and Java citronella essential oils were combined resulting in 7% lethal dose (LD₅₀) towards grain weevils. Future research should focus on optimizing extraction methods, evaluating long-term storage effects, and assessing the broader applicability of these extracts in various food products and agricultural settings. Full article

This study investigates the innovative use of natural porous clays from the Bejaad Region in Morocco as a support matrix for the encapsulation and controlled release of lemon essential oil (Citrus limonum, EOCL), a natural compound with well-documented insecticidal properties. The research aims to address the inherent challenges of essential oils, particularly their high volatility and rapid degradation, by improving their stability and insecticidal efficiency against the grain pest Sitophilus granarius. By anchoring EOCL onto clay matrices, this study seeks to achieve a sustained and controlled release of the active components, thereby enhancing their practical application as biopesticides. The clays were comprehensively characterized using advanced analytical techniques, including X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX), and thermogravimetric analysis (TGA). These techniques revealed the mineralogical composition, thermal properties, and morphology of the clays, demonstrating their suitability for effectively adsorbing and retaining EOCL. The insecticidal performance of the clay/EOCL composites was thoroughly tested under controlled conditions, revealing a marked improvement in efficacy, with significantly lower lethal doses required to achieve high mortality rates in Sitophilus granarius. The diffusion of EOCL through the clay matrix was modeled using Fick’s law of diffusion, and the results were further refined through statistical optimization to identify key parameters that influence the release and effectiveness of the active compounds. Complementing the experimental approach, a bioinformatics analysis was conducted to explore the molecular interactions between limonene, the primary active component of EOCL, and target proteins in insects. This theoretical investigation provided insights into the potential mechanisms of action, reinforcing the empirical findings. This study concludes that encapsulating EOCL within porous clay matrices not only enhances the stability and controlled release of the oil but also significantly boosts its insecticidal effectiveness. This approach presents a promising, environmentally sustainable strategy for crop protection, integrating material science, theoretical modeling, and bioinformatics to develop more efficient and durable biopesticides. Full article

Floor traps were placed in a feed mill in Greece for a period of approx. 13 months to illustrate the relative abundance and distribution of the stored product insects found. More than 20 taxa were found, with most of them belonging to Coleoptera. The most abundant species found were the rice weevil, Sitophilus oryzae (L.), and the granary weevil, Sitophilus granarius (L.), which are common primary colonizers of grains, and the confused flour beetle, Tribolium confusum Jacquelin du Val, and the red flour beetle, Tribolium castaneum (Herbst), which are secondary colonizers that usually occur in processed amylaceous commodities. Interestingly, the highest population densities of all four species were recorded during the same period, with the secondary colonizers slightly preceding the primary colonizers. Although competition among these species has been recorded in previous studies, we found that these four species could coexist during the entire trapping period in the same sampling units, which indicates possible spatial segregation and different colonization patterns in space and time. Our results demonstrate that trapping in storage and processing facilities is an essential component of decision-making regarding stored product pest management strategies in localized applications, and can drastically reduce the need for treating the entire facility. Full article

Loss of stored plant products due to insect infestation is a problem that is likely to increase with global warming. Improved storage under hermetic conditions in oxygen deficiency can prevent or control infestation and preserve product quality. Oxygen levels in hermetic storage decrease due to different factors, one of which is the oxygen consumption of the insects present. Experiments were carried out using varying numbers (25, 50, or 200) of all developmental stages of the grain weevil Sitophilus granarius L. (eggs, larvae, pupae, and adult beetles) caged and placed in sealed 30-L containers containing 22 kg of wheat for at least 21 weeks. Oxygen levels were measured at regular intervals. The oxygen consumption depended on the number of insects and went below the critical threshold of 3% for S. granarius survival in most of the trials. Some surviving beetles were observed at the end of the hermetic experiments and 12 weeks afterwards during control for progeny, when oxygen levels did not fall below the critical threshold or the low level could not be maintained for a sufficient time. Monitoring oxygen levels in hermetic storage is therefore essential to ensure safe storage over long periods. Full article

Certain plants like Rosemarinus officinalis, Lavandula angustifolia and Origanum vulgare have been used in the food industry for centuries. Cymbopogon winterianus (Java Citronella plant) is one of the most significant plants. The objective of this study is to screen for secondary metabolites by phytochemical screening, evaluate the antioxidant contents of extracts and investigate the use of the Java Citronella plant in food preservation and as an insecticide. Java Citronella powder was added to bread and evaluated for its moisture content, and a visual and sensory analysis was performed. Sitophilus granarius (L.) weevils were exposed to Java Citronella essential oil (JCEO). The phytochemical screening revealed that the extracts were abundant in secondary metabolites. The JCEO had a yield of 0.75%. The aqueous extract had a higher total phenolic content of 49.043 ± 0.217 mg GAE/g than the ethanolic extract, which was 24.478 ± 1.956 mg GAE/g. The aqueous extract had a total flavonoids content 27,725.25 ± 54.96 µg RE/g higher than the ethanolic extract, with 24,263 ± 74 µg RE/g. The ethanolic extract had stronger antioxidant activity, with anIC₅₀ = 196.116 μg/mL higher than the aqueous extract at 420 μg/mL. The 2% Java Citronella powder in the bread was preferred by consumers, and had a shelf life of 6 days. JCEO killed all the weevils with a high dose of 10% after 48 h. The Java Citronella showed insecticidal and food preservative activity. The results should help in future research to enhance the applications of Java Citronella in various domains, from food technology to insecticides. Full article

Species can coexist and infest stored products at different population densities. We evaluated the population growth of Sitophilus oryzae (L.) and Sitophilus granarius (L.) (Coleoptera: Curculionidae) on wheat and barley in laboratory conditions. Ten adults of each species were placed in vials containing wheat or barley alone or in combination, and the number of adults was counted after 65 and 120 days. These tests were performed at 25 and 30 °C. Moreover, the number of damaged grain kernels and the weight of frass produced were also recorded. In general, the simultaneous presence of both species had a negative effect on the population growth of either S. oryzae or S. granarius. Nevertheless, no significant differences were noted regarding the number of damaged kernels and the weight of frass in most of the combinations tested. Moreover, the temperature seems to have a negative effect if both species were combined, especially at 30 °C. Our results showed that there was competition in the progeny production capacity when both species were together, but this competition was temperature and commodity-mediated. Full article

Wheat, the main source of protein in the human diet, is a staple food in many countries. The yields and technological quality of wheat grain depend on both the yielding potential of wheat and the properties of wheat grain that allow its safe storage. To a large extent, losses during storage are caused by storage pests. Grains of 46 wheat cultivars were used in the study (samples weighing 20 g of each variety in 10 replications), on which the development of the grain weevil Sitophilus granarius (L.) (Coleoptera: Curculionidae) was observed (20 insects aged 3–4 days; sex ratio of 1:1). The laboratory study was carried out at constant temperature (27 OC) and humidity (75% relative humidity). The laboratory study demonstrated that the physicochemical parameters of grain (hardness, glassiness, flouriness, content of protein, sugars, starch, and crude fat), which are cultivar-dependent, can act as regulators of the development of the grain weevil. The main aim of the study was to develop recommendations regarding the breeding of wheat cultivars resistant to the foraging of S. granarius and which could therefore produce grain for longer storage, and to distinguish those that are more sensitive to the grain weevil and whose grain should therefore be supplied to the market more quickly. Knowledge of the resistance or susceptibility of individual cereal varieties to the feeding of storage pests may be useful in integrated grain storage management. Among the 46 wheat cultivars studied, five cultivars with the highest and five cultivars with the lowest susceptibility to foraging by S. granarius were identified. The highest inherent tolerance to the grain weevil was displayed by the following cultivars: KWS Livius, Bogatka, Speedway, Platin, and Julius; in contrast, the cultivars Askalon, Bamberka, Ostroga, Forum, and Muszelka proved to be the most sensitive. The chemical and physical analysis of the selected cultivars revealed a significant, positive correlation between the intensity of the development of the grain weevil, the content of starch and crude fat in the grain, and grain hardness and flouriness. Full article

Diatomaceous earth (DE) formulations are promising alternatives over the use of traditional insecticides. In the present study, a series of laboratory bioassays was carried out to assess the efficacy of three diatomaceous earth formulations, i.e., Silicid, Celatom^® MN-23, and SilicoSec^®, for the control of a wide range of stored-product insect species in soft wheat. The species tested were Tribolium confusum, Tribolium castaneum, Sitophilus oryzae, Sitophilus granarius, Rhyzopertha dominica, Oryzaephilus surinamensis, and Alphitobious diaperinus. Different dose rates, i.e., 0 (control), 100, 300, 500, and 1000 ppm, were used for each of the aforementioned dust formulations. Mortality levels of the exposed individuals were assessed after 3, 7, 14, and 21 days of exposure. Moreover, progeny were counted 65 days later. Based on our results, dust formulations were effective for the control of most of the stored-product beetle species tested. Among the DE formulations tested, Silicid could adequately control the stored-product insect species. Complete suppression of offspring was observed only for secondary species (T. confusum, T. castaneum, O. surinamensis, and A. diaperinus). For primary species (S. oryzae, S. granarius, and R. dominica), the lowest number of progeny was observed in wheat treated with Silicid. For instance, in the case of R. dominica, significantly fewer individuals were produced in Silicid-treated wheat at the highest dose rate. The results of the present study aim to encourage the utilization of DE in stored-product protection as an integrated pest management tool. Additional experimentation is required to apply the tested DE formulations in the field and on different surfaces. Full article

In this study, we evaluated the insecticidal effect of nitrogen against Sitophilus granarius (L.), Sitophilus oryzae (L.), Rhyzopertha dominica (F.), Prostephanus truncatus (Horn), Tribolium confusum Jacquelin du Val, and Oryzaephilus surinamensis (L.). Four trials were conducted in chambers containing flour in bags or sacks with >99% nitrogen level. Adults of all the above species, as well as immature life stages (eggs, larvae, and pupae) of T. confusum were used in the trials. Our results showed that nitrogen caused high mortality for all species and life stages tested. Some survival was recorded for R. dominica and T. confusum pupae. Low progeny production was recorded for S. granarius, S. oryzae, and R. dominica. In conclusion, our trials indicated that a high nitrogen environment can provide satisfactory control of various primary and secondary stored-product insect species. Full article

Phosphine resistance occurs in many areas worldwide. The present study evaluated Sitophilus species from different geographical origins using two different protocols: (i) the Food and Agriculture Organization (FAO) protocol (30 ppm for 20 h) and (ii) the dose–response protocol (50–1000 ppm for 3 d). According to our results, most of the populations tested were susceptible to phosphine. In the FAO protocol, 13 field populations out of the 35 tested were categorized as resistant to phosphine. From the populations tested, only Sitophilus oryzae (L.) G1 showed 100% active individuals after 20 h or even 7 d post-exposure. In contrast, low survival was noted for all populations of Sitophilus granarius (L.) and no survival for Sitophilus zeamais Motschulsky. Based on the dose–response protocol, no active individuals were recorded after exposure to 700 ppm for any of the populations tested. For instance, the population G1 showed 89% survival after 3 d at 50 ppm, while the respective figure at 700 ppm was 1.1.%. No survival was recorded for all concentrations and populations of S. granarius and S. zeamais. Our data show that there are considerable similarities between the two diagnostic protocols used for the evaluation of phosphine resistance of these three species. Full article

The granary weevil, Sitophilus granarius (L.), is considered a serious pest in stored grain worldwide. As residual-based protection possibilities become scarcer, the development of eco-friendly control technologies that can be implemented in practice is becoming urgent. In this spirit, our objective was to assess the effectiveness of different levels of atmospheric cooling against S. granarius under laboratory conditions. We also analysed the effects of cooling on progeny generation and the viability of treated wheat. Thus, we investigated the consequences of atmospheric exposures to temperatures of −5, −10, −15, −20, and −25 °C for 60, 75, and 90 min on these factors, and also explored the effects of nearby ranges using extrapolation. The viability of the treated wheat embryo was analysed using a TTC test. Our results showed that the highest efficacy was observed at an atmospheric cooling temperature of −25 °C (with a parallel recorded temperature of −10.5 °C in the stored grains zone), with a 90 min exposure at suboptimal relative humidity (40%). At 60% relative humidity, the mortality averages were more dispersed, and the expected efficiencies above 95% occurred at longer exposures. The post-suppressive effect of cooling can be confirmed in all three exposures. The different cooling temperatures of the tested exposure times did not produce any appreciable changes in the viability of treated wheat embryos. In conclusion, our results show that the use of atmospheric cooling can be an effective solution for stored product protection. Full article

There is ample evidence that entomopathogenic fungi can be used as alternative biological control agents for the management of insect pests in storage facilities. As the market demands more environmentally friendly methods and chemical insecticides become increasingly obsolete, more studies are being conducted to evaluate new strains of entomopathogenic fungi for their efficacy in storage facilities. In this context, we tested ten species of fungi isolated from soil, belonging to the genera Cladosporium, Condenascus, Lecanicillium, and Penicillium, for their long-term effects on economically important beetle species. Whole wheat was directly sprayed with a conidial suspension of 10⁸ spores/Ml of each of the tested fungi and then adults of Sitophilus granarius, S. oryzae, S. zeamais, Rhyzopertha dominica, and Trogoderma granarium were placed on the sprayed medium to study the mortality effects. Significantly higher mortality than the control was observed in all treatments. The lowest LT₅₀ (9.164 days) was observed in T. granarium infected with Penicillium goetzii. The isolate with the strongest results was L. dimorphum, which recorded remarkably low LT₅₀ values in S. oryzae (~11 days), R. dominica (~12 days), T. granarium (~10 days), and S. granarius (~13 days). However, for S. zeamais, it was more than 16 days. Our results confirm the existing literature on the efficacy of EPF on storage beetles, suggest the possible virulence of wild untested strains, and also highlight the importance of EPF specificity. Full article

The natural mummy of Saint Davino Armeno (11th century) is preserved in the church of Saint Michele in Foro in the city of Lucca (Tuscany, Central Italy). The body of Davino is one of the oldest Italian mummies of a Saint, and his paleopathological study was performed in 2018. In the present research, we investigated the arthropod fragments and botanical remains collected from the body, coffin, and fabrics of Saint Davino. Entomological analyses outlined the presence of 192 arthropod fragments. Among these, Diptera, Muscidae (Hydrotaea capensis and Muscina sp.), and Phoridae (Conicera sp.) puparia were the most abundant. Regarding Coleoptera, Ptinidae (Anobium punctatum) were the most frequent, followed by Cleridae (Necrobia sp.), Trogidae (Trox scaber), Curculionidae (Sitophilus granarius), and Histeridae (Gnathoncus). Cocoons of Tineidae and Pyralidae moths were found, along with a propodeum joined to the petiole and a mesopleuron of an Ichneumoninae parasitoid. Numerous metamera of Julida and three scorpion fragments were also found. Botanical samples indicated the presence of a quite broad botanical community, including gramineous species, olives, evergreen oaks, and grapevine. Overall, entomological data allow us to argue that Saint Davino was first buried into the soil, probably in a wooden coffin, thus supporting the historical-hagiographic tradition according to which he was buried sub divo in the cemetery of Saint Michele. The preservation of the body as a natural mummy may have been facilitated by burial in a coffin that prevented direct contact of the corpse with the earth. Botanical remains offer confirmation of a late medieval urban environment rich in horticultural areas and trees, giving us a landscape that is very different from the current Tuscan city. Full article