Search Results (93)

The present study highlights the critical role of surface type, insect species, and exposure duration in determining the efficacy of surface-applied insecticides in stored-product pest management. Four insecticides were sprayed and evaluated on different surfaces (concrete, metallic, plastic, and ceramic) against two beetles: the red flour beetle and the tobacco beetle. Alpha-cypermethrin and spinosad exhibited rapid and high efficacy, particularly on non-porous surfaces such as metal and ceramic, whereas pirimiphos-methyl was less effective initially and required extended exposure to achieve complete mortality, especially against Tribolium castaneum. In contrast, Lasioderma serricorne showed greater susceptibility across all insecticides and surfaces. Spinosad maintained high efficacy across all surface types, suggesting broader applicability under variable conditions. The reduced performance of insecticides on concrete surfaces underscores the influence of substrate porosity on insecticide bioavailability. Additionally, the observed delayed mortality effect in all treatments indicates that even brief exposure can result in lethal outcomes, emphasizing the long-term potential of these applications. These findings underscore the need for surface-specific application strategies and support the integration of surface treatments into comprehensive pest management programs. Further research is warranted under simulated field conditions to assess residual efficacy over time and in the presence of food, thereby enhancing the relevance of laboratory findings to real-world storage environments. Full article

Mating disruption is a commercially available management tactic for pyralid moths, which are pests of stored products. However, evaluations of efficacy have had limited replication, which limits the ability to draw conclusions about its effectiveness or the impact of different variables on its efficacy. We evaluated the mating disruption of Plodia interpunctella in 33 retail pet supply stores (6415 to 17,384 m³) and the impact of factors such as insect density and application rate on efficacy. Prior to starting MD, the average capture of P. interpunctella was 40.2 ± 3.6 moths/trap/month. Immediately after starting treatment, there was a sharp drop in captures (67.8 ± 4.8%) and then a more gradual overall downward. Overall, under mating disruption, the average reduction was 85.0 ± 3.0%. Geographic location, initial moth density, and pheromone application rate did not significantly impact efficacy. Analysis of the relationships between moth captures and mating disruption dispenser density indicated that competitive mechanisms were the primary mechanisms involved. This was the largest replicated assessment of MD for the management of a post-harvest pest and provides valuable foundational and applied insights into the process. Our results show that a standardized MD program can provide pest suppression in retail stores, but it takes time to be fully effective. Finally, identifying the primary mechanism for efficacy provides important information needed for further refinement of MD programs. Full article

Effective stored-grain insect pest detection is crucial in grain storage management to prevent economic losses and ensure food security throughout production and supply chains. Existing detection methods suffer from issues such as high labor costs, environmental interference, high equipment costs, and inconsistent performance. To address these limitations, we proposed PDA-YOLO, an improved stored-grain insect pest detection algorithm based on YOLO11n which integrates three key modules: PoolFormer_C3k2 (PF_C3k2) for efficient local feature extraction, Attention-based Intra-Scale Feature Interaction (AIFI) for enhanced global context awareness, and Dynamic Multi-scale Aware Edge (DMAE) for precise boundary detection of small targets. Trained and tested on 6200 images covering five common stored-grain insect pests (Lesser Grain Borer, Red Flour Beetle, Indian Meal Moth, Maize Weevil, and Angoumois Grain Moth), PDA-YOLO achieved an mAP@0.5 of 96.6%, mAP@0.5:0.95 of 60.4%, and F1 score of 93.5%, with a computational cost of only 6.9 G and mean detection time of 9.9 ms per image. These results demonstrate the advantages over mainstream detection algorithms, balancing accuracy, computational efficiency, and real-time performance. PDA-YOLO provides a reference for pest detection in intelligent grain storage management. Full article

Diatomaceous earth (DE) consists of fossilized remnants of diatoms, which are marine or freshwater unicellular algae. Most DEs originate from fossilized sedimentary layers of diatoms deposited in water bodies during the Eocene and Miocene periods, much more than 20 million years ago. Processed DE, a soft, chalky powder, is widely used as an insecticide due to the highly absorptive and abrasive nature of its particles. As an insecticide, DE removes the wax coating of the insect epicuticle, the primary barrier against water loss. This results in water evaporation, leading to desiccation and death of the targeted insects. This review emphasizes the co-treatment of DEs with biological agents that have insecticidal properties (e.g., essential oils, plant powders, silica gel, and species/isolates of fungi), reducing the quantities used in single-application treatments and suggesting paths for the sustainable management of insects damaging stored products. Full article

With over 1000 species of pests causing losses in both the quantity and quality of stored food, insect contamination poses significant challenges. The present study assesses the efficacy of the combination of λ-cyhalothrin and chlorantraniliprole against four key storage pests—Trogoderma granarium, Sitophilus oryzae, Rhyzopertha dominica, and Tribolium castaneum. Laboratory bioassays demonstrated species-dependent mortality, with S. oryzae and R. dominica suffering 100% mortality in several tested scenarios. A 90-day persistence trial revealed decreased efficacy over time, especially for T. granarium (32.0–71.4% at 0 days and 0.0–7.5% at 90 days) and T. castaneum (38.8–82.7% at 0 days and 0.0–12.7% at 90 days) vs. S. oryzae and R. dominica. Progeny production of S. oryzae and R. dominica was almost suppressed in persistence trials (0.4 individuals per vial and 1 individual per vial, respectively) after 30 days of storage at the dose of 5 mg/kg wheat. The results highlight the variability in insecticidal performance based on species, dose, exposure, and commodity type, emphasizing the need for tailored pest management strategies in the storage environment. Full article

The foreign grain beetle, Ahasverus advena (Waltl) (Coleoptera: Silvanidae), has been reported from 110 countries on more than 162 commodities, more than 35 types of facilities, and 14 other habitats such as compost heaps and haystacks or manure. Compost heaps, haystacks, and manure heated by fermentation may allow overwintering in cold climates, making them important sources of infestation. From these sources the A. advena can fly and infest grain storage and processing facilities. A. advena has been found in empty grain storage bins, is often found in wheat immediately after harvest, and is most abundant early in wheat storage. Larvae and adults of A. advena are well adapted to feeding on several species of fungi and have higher chitinase levels and greater tolerance for fungal aflatoxins than other species. A. advena lay more eggs on the fungal species on which their offspring can develop most successfully. They are attracted to fungal odors and high moisture commodities and have the capability to disseminate grain fungi that cause hot spots within the grain mass. The presence of fungus beetles is indicative of poor storage conditions. A. advena is capable of feeding on some commodities and is a predator that may have a potential role in biological control. They are strong fliers but are distributed extensively with the movement of commodities in the marketing system. In countries with a zero tolerance for insects, their presence is sufficient for rejection of a load and associated economic losses. In other countries, contamination by A. advena is a problem, and in India, it is listed as a quarantine pest. Extension agents have had many requests for the identification of this species, and two other species of the same genus have been found in stored products. Some information is available for the effectiveness of nine pest management methods for A. advena. Full article

Insect predators can suppress prey populations through increased progeny production. The present study investigated the numerical responses of adult♀ Xylocoris flavipes (Reuter) (Hemiptera: Anthocoridae) on a diet of Liposcelis decolor (Pearman) (Psocodea: Liposcelididae). Adult♀ X. flavipes were placed in arenas containing nymphs, adult females, or males of L. decolor at varying prey densities under laboratory conditions at 28 ± 1 °C, 63 ± 5 RH, and a 0:24 (L:D) photoperiod. The number of eggs laid by the predator was assessed at 24 h intervals for five days, and this was used to determine oviposition rate, oviposition efficiency, and efficiency of conversion of ingested food resources (ECI). This study showed that prey stage did not affect oviposition rate; however, there was a positive correlation between prey density and X. flavipes oviposition rate for all the prey stages. The predator’s oviposition efficiency and ECI (%) were inversely proportional to prey density for all prey stages. The current study shows that X. flavipes can produce more offspring on adults and nymphs of L. decolor when prey densities are high and can establish at low prey densities. Further evaluation of X. flavipes under field storage conditions is recommended to facilitate its incorporation into integrated management of psocids. Full article

Background/Objectives: Phosphine resistance in insects involves a complex interplay of genetic and physiological factors, which are often poorly understood. Resistance to high concentrations of phosphine worldwide poses a formidable challenge for stored-product pest management and affects global food security. Understanding the genetic basis of phosphine resistance in the red flour beetle, Tribolium castaneum, is urgent because of the species’ status as a notorious insect pest of stored grains and their resistance to major classes of insecticides. In this study, we take advantage of T. castaneum as a model species for biological and genetic studies. Methods: To tease apart genetic mutations and the differential expression of genes responding to phosphine intoxication, we set up 16 different exposure tests to compare the effects of phosphine dose, exposure time, and sampling time on gene expression in phosphine-susceptible and -resistant T. castaneum adults. Results: We examined the enrichment of gene ontology terms in genes that were differentially expressed and found that the data further distinguished differences in gene expression by insect strain, phosphine dose, exposure time, and recovery from phosphine exposure. The gene-encoding cytochrome P450 9e2 was expressed more in phosphine-resistant compared to phosphine-susceptible insects under all treatment conditions and was significantly higher in expression in resistant insects that were sampled after short or long phosphine exposures. Therefore, this gene may serve as a new phosphine resistance marker in T. castaneum and can further be utilized as a diagnostic tool for resistance detection. Conclusions: These data are important to understand the complex molecular changes in insects that have reduced sensitivity to phosphine to develop new monitoring and resistance prevention strategies. Full article

Tanacetum cinerariifolium, a perennial Asteraceae plant, is renowned for its ornamental value and natural insecticidal compounds, especially pyrethrins. These compounds, primarily stored in flower heads, are highly effective as insecticides with low toxicity to mammals, making them crucial for organic agriculture, along with the sesquiterpene (E)-β-farnesene (EβF), play critical roles in T. cinerariifolium defense mechanisms. However, the spatiotemporal patterns of these secondary metabolites in stems and flower heads, as well as their regulatory mechanisms, remain unclear. This study investigated the biosynthesis and regulation of pyrethrins and EβF across developmental stages (S1–S4) in flowers and stems using GC-MS and transcriptomics. Transcriptome analysis revealed that the expression of pyrethrin biosynthetic genes was not synchronized with pyrethrin accumulation. The main pyrethrin biosynthetic genes exhibited coordinated expression patterns, peaking during early flowering stages (S1–S2), while pyrethrin accumulation was primarily observed during mid-flower development. In contrast, the biosynthetic genes of EβF showed synchronized expression with EβF accumulation, with the highest activity observed in stems and early flowers. WGCNA identified jasmonic acid signaling, trichome differentiation, and terpene transport pathways as potentially associated with pyrethrin biosynthesis. Hub genes including MYC2 were identified as playing pivotal roles in regulating secondary metabolite biosynthesis. These findings provide new insights into the regulation and biosynthesis of pyrethrins and EβF, offering a foundation for optimizing bioactive compound production and advancing sustainable pest management strategies. Full article

Stored grain pests like Sitophilus oryzae pose significant challenges to food security and quality, necessitating eco-friendly pest management strategies. This study investigates the combined efficacy of reduced doses of diatomaceous earth (DE) and basil (Ocimum basilicum L.) essential oil (EO) as an alternative to conventional pesticides. Laboratory trials evaluated the effectiveness of the treatments—DE, EO, and a mixture of both (at halved doses)—against S. oryzae in wheat, alongside their impact on bread quality and sensory attributes. Results showed that DE and the DE + EO at halved doses combination achieved over 82% pest mortality, comparable to standard DE doses but with reduced mechanical and environmental drawbacks. EO alone demonstrated limited insecticidal activity. Bread made from treated wheat retained high sensory acceptability, with DE enhancing elasticity and crumb aroma. EO-enriched bread exhibited a complex aromatic profile due to methyl chavicol, though with reduced crumb elasticity and a slightly bitter aftertaste. Shelf-life assessments indicated that DE and DE + EO at halved doses extended mold-free storage by one day compared to untreated bread. These findings highlight the potential of combining DE and EO at reduced doses to manage stored grain pests sustainably, aligning with integrated pest management (IPM) and organic farming principles, while preserving the technological and sensory qualities of derived food products. Full article

Tribolium confusum is a major stored-product pest that exhibits resistance to chemically synthesized pest repellents. This study investigated the potential of essential oil (EO) extracted from the roots of Cyperus esculentus as a natural alternative for pest management. The EO was obtained through steam distillation, and its chemical composition was elucidated using gas chromatography–mass spectrometry. The primary compounds, cyperotundone and cyperene, were further isolated from the EO through silica gel column chromatography. The efficacy of the EO and its isolated compounds as pest repellents was evaluated against a flaxseed pest, which was identified as T. confusum through DNA sequence analysis. The results demonstrated that at 86.12 μg/cm², the EO and its two main components maintained significant repellent activity for up to 24 h. In contrast, the effectiveness of the positive control, N, N-diethyl-3-methylbenzamide (DEET) declined rapidly after 8 h. At 16 h, the repellent activity of the EO and one of its main components, cyperotundone, was significantly greater than that of DEET. Furthermore, at a lower concentration of 43.06 μg/cm², cyperotundone’s repellent activity was significantly stronger than DEET’s at 16 h. Additionally, cyperotundone outperformed DEET significantly from 4 to 16 h at 21.53 μg/cm² and at 16 h at 10.76 μg/cm². Among the two compounds, cyperotundone exhibited a longer-lasting repellent effect compared to cyperene, which is consistent with the lower evaporation rate of cyperotundone. Biochemical assays revealed that exposure to the EO of C. esculentus and its major compounds significantly reduced (p < 0.05) the activities of acetylcholinesterase and glutathione-S-transferase in T. confusum. Molecular docking experiments indicated that the compounds could bind to olfactory receptors with low binding energies. qRT-PCR analysis revealed that the EO and its two compounds significantly altered (p < 0.05) the expression levels of odorant receptor genes in the pest. These findings suggest that the repellent action of C. esculentus EO and its major compounds on T. confusum may be mediated through the modulation of the pest’s olfactory system, as well as by inhibiting essential enzymatic activities in the pests. This research contributes valuable insights into the development of sustainable, long-lasting, and eco-friendly pest repellents, harnessing the potential of the rich botanical resource C. esculentus. Full article

Phosphine is a widely utilized fumigant insecticide in stored-product facilities; however, its excessive application and improper usage have contributed to the emergence of resistance in insect populations. Although phosphine resistance is globally recognized, limited studies address its effects across different developmental stages. This research investigates the efficacy of phosphine on the eggs of major stored-product pests, including Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae), Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae), Tribolium castaneum, and T. confusum (Coleoptera: Tenebrionidae), focusing on strains with varying levels of phosphine susceptibility. Egg hatching rates were analyzed following exposure to phosphine concentrations ranging from 50 to 1000 ppm for durations of 1 to 7 days. Predictive models were constructed to correlate phosphine concentration and exposure time, facilitating the determination of optimal pest control strategies. The findings reveal significant differences in efficacy among species and strains, with eggs from susceptible strains experiencing complete hatch failure at 50 ppm, while resistant strains showed higher tolerance. Lethal time (LT50 and LT99) values were determined, with LT99 ranging from 6.91 to 12.95 days at 50 ppm, highlighting species-specific and age-related differences in phosphine susceptibility. Lethal concentration (LC₅₀ and LC₉₉) values could only be estimated for T. castaneum, with LC₉₉ for 1-day-old eggs ranging from 773.67 ppm to 923.03 ppm after 2.5 days of exposure. Furthermore, egg age influenced susceptibility, with 2-day-old eggs exhibiting greater mortality compared to 1-day-old eggs. This study underscores the critical role of phosphine concentration, exposure duration, and developmental stage in resistance management, providing valuable insights for enhancing fumigation protocols and improving the control of stored-product pests. Full article

Spodoptera frugiperda (Lepidoptera: Noctuidae) and Tenebrio molitor (Coleoptera: Tenebrionidae) are two prominent pests of maize and its stored grains, respectively. Botanical pesticides have been proposed as an alternative for their management. This study evaluated the insecticidal activity of Salvia connivens (Lamiaceae) methanolic extract and rosmarinic acid against S. frugiperda and T. molitor by adding them to an artificial diet, as well as their ecotoxicological effects on Poecilia reticulata (Cyprinodontiformes: Poeciliidae) and Danio rerio (Cypriniformes: Danionidae) through acute toxicity tests. The methanolic extract showed higher mortality activity against S. frugiperda (LC₅₀ = 874.28 ppm) than against T. molitor (LC₅₀ = 1856.94 ppm) and was non-toxic to fish. Rosmarinic acid, the most abundant compound in the extract (80.45 mg g⁻¹), showed higher activity against S. frugiperda (LC₅₀ = 176.81 ppm). This compound did not cause a toxic effect on adult P. reticulata at the tested concentrations. However, in P. reticulata fingerlings and D. rerio adults, it was non-toxic, except in D. rerio embryos, where it was slightly toxic. These findings suggest that S. connivens methanolic extract has potential as a botanical product for the management of S. frugiperda and T. molitor with low ecotoxicological impact, while rosmarinic acid may be a useful compound for the management of S. frugiperda. Full article

Sitophilus oryzae, Tribolium castaneum, Tribolium confusum, Oryzaephilus surinamensis, Rhyzopertha dominica, Tenebrio molitor, Trogoderma granarium, Acarus siro, and Alphitobius diaperinus represent significant arthropod stored-product pests worldwide. To combat these noxious arthropods, the current study examines the pesticidal effect of essential oils (EOs) derived from four aromatic plants, i.e., Illicium verum Hook. F., Citrus reticulata Blanco, Monodora myristica (Gaertn.) Dunal, and Xylopia aethiopica (Dunal) A. Rich. Considering the challenge of pesticide resistance, the current study focuses on assessing the efficacy of these EOs as an eco-friendly alternative to traditional synthetic insecticides. Two EO concentrations (500 and 1000 µL/kg wheat) were applied to different life stages of these pests in the bioassays. Mortality rates were monitored over several days under controlled environmental conditions. The findings demonstrated that C. reticulata and I. verum EOs had elevated insecticidal effects, especially against larval stages, resulting in 100% mortality in several species. On the contrary, M. myristica and X. aethiopica EOs showed less overall efficacy despite their potency against some pests. Both I. verum and C. reticulata EOs outperformed the positive control, pirimiphos-methyl, in several assays. The results of the current study highlight the potential of several EOs as effective alternatives in reducing synthetic pesticide use for integrated pest control management. Full article

Management of stored-product pests has historically relied on fumigation when pest populations become large. However, the ban of the fumigant methyl bromide and the ineffectiveness of other pesticides stress the need for alternative fumigants. Therefore, laboratory studies were conducted to evaluate the efficacy of ethanedinitrile (EDN) against different life stages of the mite Tyrophagus putrescentiae and to determine the sorption and desorption of EDN by dry-cured ham meat. The results showed that eggs were the most tolerant life stage to EDN fumigation, with an estimated LC₅₀ of 0.6 mg/L. Tyrophagus putrescentiae mixed life-stage colonies were controlled at 1.3 mg/L, and less than 0.05% of the population survived following treatment with 0.6 mg/L within 24 h at 25 °C. The free-headspace concentrations of EDN in fumigation chambers containing ham decreased by 97% of the initial concentrations applied (2.6 and 4.8 mg/L) after the 24 h fumigation period. The EDN sorption in ham followed the first-order kinetics, with half-life values of 5.0 and 4.9 h for 2.6 and 4.8 mg/L, respectively. The percentage losses of EDN per hour were calculated to be 12.8 and 13.2% at 2.6 and 4.8 mg/L, respectively. Our study indicates that EDN controls T. putrescentiae in the laboratory. Full article