Insecticide Products Research Articles

Toxicological characterization of the insecticide metofluthrin and assessment of the carcinogenic risk to human health due to its chronic inhalation effect

The aim of the investigation is the toxicological characterization and analysis of the danger criteria of the insecticide metofluthrin with an assessment of the carcinogenic risk to health caused by chronic inhalation exposure to the substance at the level of the maximum possible concentrations in the air environment of human life. The analysis of scientific reports of the US Environmental Protection Agency (US EPA) and the European Chemicals Agency (ECHA) on the toxicological properties of metofluthrin was carried out. The assessment of the risk of the development of carcinogenic effects due to chronic inhalation exposure to metofluthrin was carried out taking into account the average daily dose of the substance that can enter the human body during the natural life span (LADD) and the carcinogenic potential factor (SF) in accordance with domestic guidelines. Classification of levels of carcinogenic risk was carried out using domestic and international approaches. It was established that the limiting criteria for the danger of metofluthrin are the average lethal concentration in air (LC50 =1080 mg/m³) and the size of the zone of chronic action (Zch=7.46), which characterizes the danger of occurrence of chronic intoxication due to long-term inhalation exposure. According to these indicators, metofluthrin is classified as a dangerous substance (hazard class 2). The key effects of the toxic action of metofluthrin are determined – neurotoxicity, hepatotoxicity and nephrotoxicity. The threshold non-genotoxic oncogenic potential of metofluthrin according to the phenobarbital type was established. Individual carcinogenic risk under different scenarios of chronic inhalation exposure to metofluthrin was calculated. The substance concentration of 3.54 mg/m³ leads to a high level of risk (1.5×10-3), which is considered unacceptable for production conditions and the population. At concentrations of 0.28 mg/m³ and 1.0 mg/m³, the risk is estimated as average and acceptable for production conditions (1.1-4.1×10-4). The risk of exposure to a concentration of 0.14 mg/m³ is classified as low and acceptable for the population (5.7×10-5). Thus, the results obtained in the study indicate that such concentrations of metofluthrin in the air as 0.14 – 0.28 – 1.0 mg/m³ are safe for human health, subject to compliance with medical and sanitary regulations at the stage of production and application of insecticides based on metofluthrin as prescribed.

Essential Oil with Mosquito-Repellent Potential from Plectranthus Amboinicus Leaves Against Aedes Aegypti via Human Volunteer Study

Plectranthus amboinicus(PA) is a highly aromatic perennial shrub that belongs to the Lamiaceae family. It has thick, fleshy and succulent leaves and stem. The margins of the leaves contain numerous glandular hairs that produce essential oil. The essential oil of PA(PAEO) exhibits therapeutical, nutritional, antioxidant, antimicrobial, insecticidal, and insect repellent potentials. The objective of this study was to evaluate and compare the repellent properties of PAEO and DEET against Aedes aegypti mosquitoes, which are known carriers of dengue fever. The extraction of PAEO was carried out using hydrodistillation method while the chemical profile was analysed by gas chromatography-mass spectrometry (GC-MS) technique. The bioefficacy test was conducted according to the household insecticide products personal mosquito repellent evaluation method for biological efficacy (First revision) (MS1497:2007) provided by the Standard and Industrial Research Institute of Malaysia (SIRIM) with slight modification. 10% PAEO was used as test solution while 10% DEET was used as positive control. Fabric and patches treated with 10% PAEO were tested on human volunteers. Both the fabric and the patch, treated with 10% PAEO, exhibit excellent repellency (97 - 100%) against Ae. aegypti mosquitoes for a duration of up to 240 min (4 h) post-application. In contrast, 10% DEET, which initially showed a comparable repellency (99%) 30 min after application, experiences a gradual decline in repellency over time, reaching a 51% repellency rate at the end of the test (240 min post-application). A two-way ANOVA analysis indicates significant effect for type of treatment (p = 0.016) but with no significant difference between the exposure time. Tukey’s test showed significant differences between 10% PAEO-treated patches and 10% DEET (p = 0.016), and between 10% PAEO-treated fabric and 10% DEET (p = 0.026). These findings suggest that PAEO is potentially an effective natural repellent against Ae. aegypti.

Common consumer residual insecticides lack efficacy against insecticide-susceptible and resistant populations of the German cockroach (Blattodea: Ectobiidae).

The German cockroach, Blattella germanica (L.) (Blattodea: Ectobiidae), is a ubiquitous pest in affordable housing. They represent a major threat to human health due to their contribution of asthma-exacerbating allergens and the potential to transfer pathogenic microorganisms indoors. Despite well-documented pyrethroid resistance, pyrethroid-based broadcast residual insecticide products are often used by residents to control cockroaches in their homes. Additionally, there is little empirical independent testing of these products. Thus, it remains unclear how effective these commonly used do-it-yourself products are at controlling German cockroaches. This study represents a comprehensive examination of the efficacy of these products with direct, limited, and continuous exposure assays on a variety of common household surfaces on field populations of cockroaches with varying levels of pyrethroid resistance. While most products performed well when applied directly to test insects, mortality was substantially lower across all surfaces with limited exposure (30min). In continuous exposure assays on a nonporous surface, products took at least 24hr to cause 100% mortality in a field population, with some products taking up to 5d to achieve 100% mortality. The findings of this study demonstrate a lack of residual efficacy from common pyrethroid-based consumer-use pesticides products. Given that it is not feasible to find and treat every cockroach in a home directly, the residuality of spray-based formulations is critical for products designed to control German cockroaches. Without residual efficacy, as shown in the consumer aerosol and spray products tested, we expect these products to add little to no value to cockroach control.

Efficacy of plant-based products and nonconventional pesticides for the management of tropical bed bug.

Insecticide resistance is widespread in global bed bug populations. Both common bed bugs and tropical bed bugs are pyrethroid-resistant among most field populations. Plant-based products and nonconventional pesticides offer minimal-risk strategies for managing bed bug resistance, but this strategy has yet to be formally evaluated in Cimex hemipterus (F.) (Hemiptera: Cimicidae). Here, several commercial plant-based formulations (Cedarcide, EcoRaider (also known as EcoVenger), EcoSMART, and Bio-D), a novel product, Provecta, and a pyrethroid insecticide, Pesguard FG161 were tested against pyrethroid-susceptible and resistant strains of C. hemipterus using direct spray, residual exposure, and egg dipping assays. Direct spray treatments outperform residual applications against all tested bed bug strains. Cedarcide exhibits the highest consistency in eliminating bed bugs, followed by EcoRaider, EcoSMART, and Provecta that outperform Bio-D and Pesguard FG161. In comparison to Pesguard FG161, all plant-based insecticide products and Provecta showed higher efficacy against pyrethroid-resistant strains. Although effective, product efficacy varies in terms of speed. Cedarcide kills all bed bugs within 1 min after spraying; however, other products can take up to 9 days to achieve 100% mortality. The efficacy of all products was reduced when evaluated on fabric surface (42%-65% mortality). Cedarcide and EcoRaider reduced egg hatchability by 37%-73% and 47%-70%, respectively. This study suggests that certain plant-based insecticides and an unconventional insecticide can serve as alternative direct spray treatments for managing tropical bed bugs, though their residual effects are limited.

Evaluation of the In2Care Mosquito Station at low deployment density: a field study to manage Aedes aegypti and Culex quinquefasciatus (Diptera: Culicidae) in North Central Florida.

In the last 2 decades, there has been an increase in the geographic range and frequency of vector-borne diseases. Management of mosquito populations has become challenging due to increasing rates of resistance to existing insecticidal products and formulations. Several alternative tools have emerged to suppress or replace mosquito populations. One of these tools is the In2Care Mosquito Station (In2Care station). This dual-action station contains the insect growth regulator pyriproxyfen which disrupts the development of immatures and the entomopathogenic fungus Beauveria bassiana (B. bassiana) strain GHA which kills exposed adult mosquitoes. The In2Care stations have previously been shown to effectively control Aedes aegypti in field settings at a density of 6 stations/acre rather than the label-recommended 10 stations/acre. To further test the efficacy of low station density deployment, we deployed In2Care stations in the Pleasant Street Historic District of Gainesville, Florida, at a density of 3 stations/acre over a period of 2 years in the presence or absence of ground larvicidal applications. The deployment of stations resulted in no measurable impact on Ae. aegypti and Culex quinquefasciatus adult or immature abundance suggesting that the low-density deployment of In2Care stations is insufficient to reduce Ae. aegypti and Cu. quinquefasciatus abundance within treatment areas.

Trends in poisoning associated with the use of insecticides for bed bug infestations: a 20-year retrospective study in France

Bed bugs are pervasive global pests that have reemerged in the last 20 years as a significant public health concern, especially in densely populated urban areas. Beyond financial losses, expenses, inconvenience, and psychological distress, bed bug infestations often necessitate chemical management, posing poisoning risks to those with an infestation. The French Poison Control Centers recorded 1056 cases of exposure to bed bug insecticide products between 1999 and 2021. This study followed cases over 2007–2021, with a notable surge in reports of adverse reactions from 2016 onwards. Data revealed an increased recurrent misuse of insecticides, including substances banned or not approved for this use. Our findings underscore the growing public reliance on chemical insecticides for home bed bug management. With this is the concern of increased poisoning risks, and potential long-term health consequences from non-professional efforts by the public to manage bed bugs in their homes. This escalating trend emphasizes the need for safer and more sustainable pest management strategies in urban environments.

Toxicity of cockroach gel baits to the oothecal parasitoid Aprostocetus hagenowii (Hymenoptera: Eulophidae) and implications for cockroach integrated pest management.

Aprostocetus hagenowii (Ratzeburg) is a parasitoid wasp that parasitizes the oothecae of peridomestic pest cockroaches. A. hagenowii has been used in integrated pest management (IPM) programs for cockroach control but little is known about how this parasitoid responds to the insecticides commonly used for cockroach management. Five insecticidal gel bait products containing indoxacarb, clothianidin, fipronil, dinotefuran, or abamectin B1 were tested for their toxicity towards A. hagenowii and the American cockroach, Periplaneta americana (L.; Blattodea: Blattidae), a host of A. hagenowii and a common pest. All baits were tested as fresh and 1-d aged deposits. Indoxacarb was the only active ingredient that did not cause significant (P < 0.05) A. hagenowii mortality compared to the control in both the fresh and aged gel experiments (Median survival time [MST]s: 168 h fresh, 72 h aged). Clothianidin caused the lowest A. hagenowii MSTs across experiments (24 h, fresh and aged). All baits caused significant P. americana mortality as fresh and 1-d aged deposits (P < 0.05). Indoxacarb appears most compatible with A. hagenowii in cockroach IPM.

Exposure of Young Children to Permethrin and Cypermethrin Insecticides in the Residential Environment.

The aims of this study were to evaluate the exposure to permethrin and cypermethrin of young children aged between 2 and 5 years in Nakhon Pathom and Sing Buri provinces, Thailand. A questionnaire that included general demographic information, household characteristics, insecticide usage and exposure-related behavior in children was used to interview parents or family caregivers. Permethrin and cypermethrin concentrations on floor surfaces and children's hands, as well as their urinary metabolites, were analyzed by gas chromatography coupled with mass spectrometry. The results showed that permethrin and cypermethrin were detected in 62% and 83% of the children's hand wipe samples, with geometric mean (GM) levels of 0.02 µg and 0.04 µg, respectively. Permethrin and cypermethrin were detected in 79% and 93% of floor surface wipe samples, with GM levels of 0.90 µg/m2, and 1.49 µg/m2, respectively. For children's urine, the GM concentrations of cis- and trans-DCCA, 3-PBA, and total pyrethroid metabolites were 0.84, 0.31 and 1.23 nmol/g creatinine, respectively. This study found that household insecticide product usage and having a tile floor were associated with increased permethrin concentrations on the children's hands and floor surfaces. However, cypermethrin concentrations on floor surfaces were significantly higher in families using aerosol insecticide sprays and insecticide products in the living room and bedroom. The predictors of the total pyrethroid, DCCA and 3-PBA metabolites are permethrin on children's hands or floor surfaces and cypermethrin on floor surfaces.

Assessing the effectiveness, biosafety, and resident’s perception of a micro-encapsulated propoxur paint against Aedes aegypti: a field trial in a dengue-affected community of Sonora, Mexico

Mosquito-borne diseases remain a major public health concern in the Region of the Americas. Concerning dengue, Mexico ranked as the third American country with the highest number of cases in 2023, following Brazil and Peru. In this sense, the development and production of safer, eco-friendly, cost-effective, more efficient, and target-specific insecticides have become essential in disease control strategies. This study aimed to assess the effectiveness and safety of indoor micro-encapsulated propoxur paint against Aedes aegypti, estimate residents' exposure via cholinesterase levels, and gauge resident perceptions in the rural village Poblado Miguel Alemán (PMA), Sonora, Mexico. Houses in PMA were organised into four blocks for a field trial, with different treatments on interior walls: 1) full insecticide paint coverage; 2) insecticide paint applied up to 1 meter; 3) full indoor residual spraying; and 4) no treatment (control). Mosquito surveys were conducted before and after interventions. Blood samples from residents were analysed for cholinesterase levels, while perceptions were gathered through a questionnaire. Aedes resting density correlated closely with the paint formulation and coverage. Full-surface insecticide paint showed the greatest reduction. Both paint interventions notably impacted Aedes breeding, with substantial reductions in House Index (20.1% IP, 31.2% IP 1 m) and Container Index (51.8% IP, 61.7% IP 1 m) compared to the control over one year. Post-intervention blood cholinesterase activity remained within acceptable limits. Over 80% of residents expressed satisfaction with the interventions. The use of propoxur paint proves to be a safe, effective, and well-accepted method for decreasing Ae. aegypti populations in urban areas.

Insecticidal activity of Aguaria salicifolia leaf extracts on cowpea bruchid Callosobruchus maculatus (Coleoptera: Chrysomelidae)

The protection of foodstuffs against insect pests constitutes a serious problem across the world. Synthetic chemical insecticides are the most widely used method for grain protection. Unfortunately, the harmful effects of these insecticides on human health and environment have increased the interest of researchers for botanical insecticides which are recognized as eco-friendly products. Therefore, the efficacy of Aguaria salicifolia Hook. f. ex Oliv. leaf extracts was tested against Callosobruchus maculatus F. on cowpea grain, at the dosage of 2, 4, 8 and 16 g/kg. To estimate the biological activity of leaf powder and aqueous extract, adult mortality, insect population growth reduction, grain damage and weight loss reduction tests were carried out. The repellency effect of A. salicifolia was assessed using the aqueous, methanolic and ethyl acetate extracts. The mortality was recorded at 1, 3, 5 and 6 days post-exposure. All treatments were submitted to four replications, and the experiment was carried out in a completely randomised design in the fluctuating laboratory conditions (Temp. = 23.71 ± 1.03 °C; RH. = 81.38 ± 2.03 %). Overall, all the extracts significantly exhibited insecticidal activities against cowpea bruchids. The highest dosage induced the highest mortality rates; 79.26 % and 84.08 % with aqueous extract and leaf powder, respectively. The different plant extracts considerably reduced insect population, grain damage and weight loss. The complete reduction of C. maculatus population was achieved by aqueous extract of A. salicifolia. The different solvent extracts had repellent property with repellency percentage values ranging from 30 % to 73.75 %. Considering these results, insecticidal products derived from A. salicifolia could constitute an alternative to the chemical synthetic insecticides used against C. maculatus. However, further studies are needed to be carried out concerning the mammalian toxicity and evaluation of suitable formulations of the extracts under field conditions before their promotion for grain protection.

Activity of Rosmarinus officinalis (Lamiales: Lamiaceae) Essential Oil and Its Main Constituent, 1,8-Cineole, against Tribolium castaneum (Coleoptera: Tenebrionidae)1

Abstract Rosemary essential oil (EO), from Rosmarinus officinalis L. (Lamiales: Lamiaceae), has potent properties against stored insect pests. This study aimed to evaluate the efficacy of EOs from both manually extracted and commercially produced R. officinalis, as well as the main compound 1,8-cineole, against adults of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). Chemical analysis of the R. officinalis EOs was conducted using a gas chromatograph–mass spectrometer. Toxicity and repellent effects were assessed through contact and fumigation bioassays in a factorial experimental design with five replicates. Each R. officinalis EO type showed nine major compounds (&amp;gt;90%), with 1,8-cineol as the predominant component (&amp;gt;52%). Contact toxicity bioassays showed 1,8-cineole had a median lethal concentration of 1.12% at 48 h, 1.54% for manually extracted EOs, and 1.64% for commercially produced R. officinalis EOs. Furthermore, 0.5% of 1,8-cineole displayed strong contact efficacy against T. castaneum. Fumigant toxicity was observed at 140.07, 127.28, and 121.52 μl/L air, respectively. Manually extracted EO at 160 μl/L air demonstrated strong fumigant efficacy against T. castaneum, acting as a contact (66–94%) and fumigant (82–69%) repellent within 8 h, outperforming commercially produced EO and 1,8-cineole. These findings highlight the potential of manually extracted EO from R. officinalis as a natural insecticide, effective in both contact and fumigation against T. castaneum. This offers a promising avenue for using plant extracts in storage pest prevention, potentially leading to the development of insecticide products.

Preparation and Application of Volatilized Wormwood Essence Derived Naturally into Green Insecticide.

Naturally occurring substances and their derivatives function as vital resources for pesticides that can be used in fields, such as insecticide production and fungicide development. As a botanical entity displaying multifaceted biological functions, wormwood has received thorough scrutiny across multiple sectors. The insect repellency potency combined with antibacterial and antifungal activities of wormwood position it as a potential candidate for prospective development into eco-friendly chemical pesticides. In this research, Wormwood essential oil was procured via ethanol water under ultrasonic scenarios and subsequently diluted with PEG 400 to formulate green chemical pesticides. The defensive efficacy of this green pesticide on plants was validated through 2 weeks of clustered plant growth experiments. Active constituents that exerted their effects were scrutinized by GC-MS. Furthermore, this green pesticide also displays efficacious effects on the prevention and management of aphids, exhibiting a dose-dependent relationship. 4-terpenol, eucalyptol, carvacrol, and L-borneol were identified by GC-MS as the predominant active constituents in this green chemical pesticide. Wormwood can be leveraged to develop green chemical pesticides, which can protect plants without contaminating the environment.

Potential use of pinenes to improve localized insecticide injections targeting the western drywood termite (Blattodea: Kalotermitidae).

The western drywood termite, Incisitermes minor (Hagen), causes significant economic damage to wood structures in the United States of America, especially California. When infestation is not widespread, localized insecticide injections may be useful for remedial control. However, the extensive gallery structure of drywood termites and their tendency to aggregate at specific parts of the galleries can impact the efficacy of localized insecticide injection. Chemicals that attract termites from a distance may improve the localized insecticide injection by increasing the number of termites contacting the insecticide residues. Two volatile terpenes, α-pinene and β-pinene, commonly found in many coniferous timber trees, were applied to artificial termite galleries to determine if termites were attracted from their original aggregation site. Furthermore, we examined if adding these pinenes would improve the overall efficacy of some insecticide products for drywood termite control. Behavioral assay results showed that the treatment with pinenes increased the likelihood that drywood termites would leave their original aggregation site and contact the treated part of the gallery. When tested with the pesticide products applied in a small area away from the termite aggregation, β-pinene significantly accelerated the time course of mortality for the aqueous fipronil. The efficacy of disodium octaborate tetrahydrate dust was not influenced by the addition of pinenes. Implications for drywood termite management and future research directions are discussed.

Wild plants with toxic properties and with insecticidal potential organic against pests agricultural

In this work, 15 plants are listed, which are considered to have toxic effects in different areas of Durango. In addition, their main characteristics, distribution, properties and uses are described. Most toxic plants cause problems to human health such as: irritations, burns, vomiting, diarrhea and in some extreme cases these can cause death if we exceed the dose. On the other hand, these qualities can be used to benefit the environment, by extracting toxic secondary metabolites and using them to control pests, whether for forestry or agricultural insects, and thus reduce damage to the entomofauna of the area. Therefore, the objective of this review is to inform and identify the location of toxic plants in the state of Durango, uses and distribution. Furthermore, since the plants listed here do not have any harmful effects on the environment, their possible use in the production of biorational insecticides against insects is considered, which can be part of integrated pest management.

The Effect of Social Norms on Residential Insecticide Use.

Insecticide products are widely used in homes around the world, despite concerns about their adverse health effects. Variations in insecticide use levels can stem not only from differences in environmental conditions, but also from societal factors. This study investigates the impact of religiosity on insecticide use in Jewish households, hypothesizing that religious families might use more insecticides because insects are considered taboo in Judaism. Data from interviews with 70 families, examining their insecticide use, exposure to pests, aversion to cockroaches, and other predisposing factors, revealed that despite similar levels of pest exposure, religious families reported higher insecticide use and greater aversion to cockroaches. Multiple linear regression analysis identified religiosity as the primary predictor of insecticide use, followed by pest exposure levels. The elevated insecticide use among religious Jewish families may stem from several factors, with the Jewish categorization of insects as "impure animals" that should be strictly avoided likely playing a crucial role in promoting insecticide use. Understanding how attitudes toward insects influence insecticide use across different societies is crucial for health and environmental authorities to develop novel insecticide-reduction initiatives that will be tailored to the unique social characteristics of various communities.

Correction to “Synthesis and Insecticidal Activity Evaluation of Potential Insecticidal Natural Product Borrelidin Analogs Toward New Pesticides”

Correction to “Synthesis and Insecticidal Activity Evaluation of Potential Insecticidal Natural Product Borrelidin Analogs Toward New Pesticides”

Rifampicin synergizes the toxicity of insecticides against the green peach aphid, Myzus persicae

Myzus persicae is an important pest that has developed resistance to nearly all currently used insecticidal products. The employment of insecticide synergists is one of the effective strategies that need to be developed for the management of this resistance. Our study showed that treatment with a combination of the antibiotic, rifampicin, with imidacloprid, cyantraniliprole, or clothianidin significantly increased their toxicities against M. persicae, by 2.72, 3.59, and 2.41 folds, respectively. Rifampicin treatment led to a noteworthy reduction in the activities of multifunctional oxidases (by 32.64%) and esterases (by 23.80%), along with a decrease in the expression of the CYP6CY3 gene (by 58.57%) in M. persicae. It also negatively impacted the fitness of the aphids, including weight, life span, number of offspring, and elongation of developmental duration. In addition, bioassays showed that the combination of rifampicin and a detoxification enzyme inhibitor, piperonyl butoxide, or dsRNA of CYP6CY3 further significantly improved the toxicity of imidacloprid against M. persicae, by 6.19- and 7.55-fold, respectively. The present study suggests that development of active ingredients such as rifampicin as candidate synergists, show promise to overcome metabolic resistance to insecticides in aphids.

A Review of Endophytic Fungi and their Applications in Different Fields of Biotechnology

Endophytic fungus is an intriguing group of organisms that live inside their host's living tissues, which are primarily higher plants. Endophytes generate naturally occurring bioactive chemicals that are thought to operate as an elicitor for the synthesis of secondary metabolites in plants, without causing any disease symptoms in the host cells. By imparting stress tolerance and enhancing host resistance to a range of diseases, this incredibly varied collection of fungus can have a significant influence on plant ecosystems. They are known to improve nutrition through the reversible exchange of nutrients and protect plants from infections, which in turn affects development by releasing plant growth hormones. Endophytic fungus-infected plants exhibit notable increases in biomass, enhance commercial plant output, and are therefore beneficial to the agricultural industry. The potential uses of endophytic fungi as biological vectors, biological control agents, and insecticidal products, sources of secondary metabolites, antimicrobial agents, antitumor compounds, antibiotics, immunosuppressants, and antidiabetic agents make them of biotechnological interest. The current study concentrated on the numerous uses of fungal endophytes in several biotechnology fields.

Protatrans – growth biostimulants for centomopathogenic bacteria &lt;i&gt;Bacillus thuringiensis&lt;/i&gt;

The study investigates the use of protatran compounds as growth stimulators for Bacillus thuringiensis bacteria, which are widely used as producers of biopesticides. Cultivation of the Bacillus thuringiensis strain subsp. kurstaki was carried out in a Luria-Bertani (LB) liquid medium. Protatrans (2-Me-C6H4OCH2COO- were added to the NN+(CH2CH2OH)3 (1), 4-Cl-C6H4 -SCH2COO-NN(CHCHOH) (2) and 4-Cl-CSOCHCOO NN+(CH2CH2OH)3 (3) media in concentrations of 1×10-4–1×10-8wt %. The LB medium without the addition of compounds 1–3 was used as a control. Cultures were incubated at a temperature of 30°C for 24 hours. The number of Bacillus thuringiensis cells was determined by serial dilution. The maximum growth was observed in a medium containing 1×10-4wt % of protatran 3. The number of cells was almost 10 times (966.7%) higher than in the control. In media with 1×10-5, 1×10-6, 1×10-7 and 1×10-8 wt % of compound 3, the number of cells was 4–7 times higher than in the control (by 371.7–666.7%). Protatrans 1 and 2 had a positive effect on Bacillus thuringiensis, increasing the number of cells by 83–292% compared to control. Therefore, it was demonstrated for the first time that commercially available non-toxic protatran compounds in microconcentrations are powerful growth stimulators for the entomopathogenic bacteria Bacillus thuringiensis. This indicates the potential for significant improvement and cost reduction of biotechnology for the production of bacterial insecticides based on Bacillus thuringiensis, used in agriculture, forestry and homesteads to control harmful insects.

Physiological Quality of Treated and Stored Barley Seeds

Industrial seed treatment (IST) is used in some grain crops. However, the products used often impair the quality of seeds, especially insecticides. In the case of barley seeds, investigative studies on the use of IST are scarce. The present study aimed to evaluate the influence of IST with the fungicide (Iprodione) and insecticide (Thiamethoxan) products, mixed or not, on the physiological quality of barley seeds, before and after storage for two months. A completely randomized design was used, in a 4x2 factorial scheme, with four replications. The treatments consisted of four combinations of applications carried out via IST on barley seeds, of chemical pesticides (fungicide/insecticide), alone or in mixtures, as follows: {T1 &amp;ndash; fungicide Iprodione (Rovral); T2 &amp;ndash; Thiamethoxan insecticide (Cruizer); T3 &amp;ndash; mixture of fungicide/insecticide products (Iprodione + Thiamethoxan); T4 &amp;ndash; Control)}, submitted to storage for two months, with evaluations carried out at T0 (treated and analyzed seeds) and T1 (treated seeds stored for 60 days). The following tests were carried out: water content, germination, first count, accelerated aging, seedling length, seedling dry mass. It was concluded that the germination of barley seeds treated with the fungicide Iprodione (Rovral&amp;reg;) and the insecticide Thiamethoxan (Cruizer&amp;reg;), alone and in a mixture applied via IST, maintained the physiological quality of the seeds within the standards for commercialization until 60 days of storage. The use of the insecticide Thiamethoxan (Cruizer&amp;reg;) via IST showed greater damage to the physiology of barley seeds during storage (60 days), applied alone or in a mixture with the fungicide Iprodione (Rovral &amp;reg;).