Biopesticides Research Articles

Development of a Deep Learning‐Assisted Mobile Application for the Identification of Nematodes Through Microscopic Images

ABSTRACTNematodes are microscopic metazoans, some species of which can be used as biological insecticides, while some other species annually damage 10.0%–20.0% of crops globally. Accurate identification of nematodes is crucial for their effective utilisation or control. Current methods of nematode identification are labour‐intensive, time‐consuming, and prone to false positives, thus necessitating the development of an intelligent system for their identification from microscopic images without technical assistance. In this study, a novel approach was investigated for the identification of nematodes from microscopic images. A novel lightweight convolutional neural network (CNN) was developed to identify the nematodes belonging to different trophic groups (Heterorhabditis indica, Meloidogyne incognita, Helicotylenchus, Anguina tritici, and Xiphinema). The CNN model was trained for 75 epochs using 70.0% of the nematode dataset, with validation on 20.0% of the dataset. To ensure unbiased evaluation, 30 images from each class were randomly selected from the remaining 10.0% of the dataset for testing the classification performance of the trained model. The trained models achieved an average classification accuracy, precision, recall, and F1‐score values of 98.52%, 95.66%, 95.56%, and 95.56%, respectively. The proposed CNN was found to be four times faster and five times lighter against a marginal (< 1.0%) decrease in accuracy when compared with the existing state‐of‐the‐art CNNs. The classification accuracy of the developed mobile application was validated by nematode specialists on freshly captured data and found to be greater than 98.0%. Hence, the developed mobile application can be effectively applied for the identification of targeted nematodes and eliminate the necessity of specialists.

The Effect of Some Biological Fungicides and Liquid Organic Fertilizers on Sigatoka Disease on ‘Mas’ Banana Plants (Musa acuminata Colla)

Banana (Musa acuminata Colla) is a tropical fruit with great economic potential and export prospects. According to the Directorate General of Horticulture, Ministry of Agriculture, banana production from 2009 to 2014 fluctuated due to attacks by Plant Destruction Organisms (PDO), particularly Sigatoka disease caused by the fungus Mycosphaerella musciola. This study investigated biological agents like Trichoderma sp. and Gliocladium sp., along with liquid organic fertilizers, to control the disease without synthetic fungicides.The research, conducted at the University of Muhammadiyah Malang, used a split-plot design with two factors: biological pesticides (Tricogreen, Natural Glio, Trico-G) and liquid organic fertilizers (rabbit urine POC, shrimp shell MOL, banana hump MOL). The experiment had nine treatment combinations with three plant samples each. Results showed that biological pesticides significantly reduced Sigatoka disease intensity, with the J3P3 treatment (Trico-G and Banana Hump MOL) achieving the lowest infection rate of 29.55%, reducing disease intensity by 70.45%. Liquid organic fertilizers also improved plant growth, increasing leaf number and leaf area. This indicates that biological agents and organic fertilizers effectively manage Sigatoka disease and promote healthy banana plant growth.

Side effects of insecticides used for management of Tuta absoluta Meyrick (Lepidoptera: Gelechidae) on the biocontrol agent Trichogramma brassicae Bezdenko (Hymenoptera: Trichogrammatidae)

Trichogramma brassicae is one of the most important egg parasitoids of many pests including South American tomato pinworm, Tuta absoluta (Lepidoptera: Gelechiidae). In agrosystems, the function of parasitoids can be affected by the application of insecticides. To use biological control agents and pesticides simultaneously in pest management, it is necessary to know the potential effect of pesticides on biological control agents. In this study, the lethal and sublethal effects of four insecticides (flubendiamide, emamectin benzoate + lufenuron, thiocyclam, and spinosad) frequently used to control T. absoluta, were investigated on its parasitoid Trichogramma Brassicae Bezdenko (Hymenoptera: Trichogrammatidae), under controlled laboratory conditions. The results showed that spinosad with an LC50 value of 0.73 mg a.i./ L was highly toxic against adults of T. brassicae in comparison to flubendiamide (4.09 mg a.i./ L), emamectin benzoate + lufenuron (4.17 mg a.i./ L), and thiocyclam (9.59 mg a.i./ L). Furthermore, key demographic parameters such as net reproductive rate (R0), intrinsic rate of increase (rm), mean generation time (T), and doubling time (DT) were significantly decreased after exposure of T. brassicae to the LC30s of spinosad, thiocyclam, flubendiamide, and emamectin benzoate + lufenuron compared to the control. In the light of our results, the four insecticides should be used cautiously in T. absoluta integrated management programs. While the thiocyclam can be combined with the T. brassicae, the flubendiamide and emamectin benzoate + lufenuron are not recommended in the presence of this parasitoid. The use of spinosad should be avoided concomitantly with the release of T. brassicae.

Alternatives for controlling insect pests in crops of agronomic interest using Bacillus thuringiensis and Brevibacillus laterosporus

The bacteria Bacillus subtilis and Bacillus thuringiensis have been the main target of research for a long time, making it necessary to identify new microorganisms capable of being used and that accompany the rapid development of biotechnology. The work aims to evaluate the efficiency of isolates of B. thuringiensis and B. laterosporus in controlling caterpillars in crops of agronomic interest. Experiments were conducted with the cultivation of Cotton, Sugarcane, Citrus, Bean, Cabbage, Maize, Soybean and Wheat in different environments to evaluate the efficiency of B. thuringiensis and B. laterosporus isolates in controlling caterpillars. Analysis of variance took place at 5% probability using the F test. Subsequently, the Scott-Knott grouping of means was used at 5% probability. The synergistic use of chemical and biological insecticides promotes satisfactory rates of pest control in crops of agronomic interest. Isolates of B. thuringiensis and B. laterosporus are efficient in controlling caterpillars when applied at the highest dosages tested.

The application ozone within the food industry, mode of action, current and future applications, and regulatory compliance.

The food industry faces numerous challenges today, with the prevention and reduction of microbial contamination being a critical focus. While traditional chemical-based methods are effective and widely used, rising energy costs, the development of microbial tolerances, and growing awareness of the ecological impact of chemical biocides have renewed interest in novel biocides. Ozone, in both its gaseous and aqueous forms, is recognized as a potent disinfectant against bacteria, viruses, and fungi due to its high oxidation potential. Our review highlights several studies on the applications of ozone within the food industry, including its use for surface and aerosol disinfection and its capacity to reduce viable Listeria monocytogenes, a pertinent foodborne pathogen harbouring environmental and biocide stress tolerances and biofilm former. We also explore the use of ozone in food treatment and preservation, specifically on blueberries, apples, carrots, cabbage and cherry tomatoes. While ozone is an effective disinfectant, it is important to consider material incompatibility, and the risks associated with prolonged human exposure to high concentrations. Nevertheless, for certain applications, ozone proves to be an efficacious and valuable alternative or complementary method for microbial control. Compliance with the Biocide Products Regulation (BPR) will require ozone device manufacturers to produce proven efficacy and safety data in line with British standards based on European standards (BS EN), and researchers to propose adaptations to account for ozone's unique properties.

Consumer acceptance of bacteriophage technology for microbial control

As global concerns and awareness of the threat posed by antimicrobial resistance (AMR) grow, the One Health initiative provides a framework to advance public understanding of and willingness to address AMR. The use of bacteriophages as a non-antibiotic means to control bacterial infections aligns with this framework, but it is unknown whether the use of new antibiotic alternatives, and bacteriophages in particular, will find acceptance among consumers. Within the context of poultry production and consumption, we sampled 1497 Pakistani consumers studying their knowledge of and familiarity with antibiotics, bacteriophages and AMR, whether they perceived AMR as a threat, and their willingness to accept alternative microbial control technologies. Additionally, we tested the impact information about bacteriophages had on the different concepts as well as respondents’ perception of different chicken quality attributes. Using both Probit and Multivariate Probit models we found that familiarity with antibiotics and bacteriophages is significantly associated with the acceptance of alternative microbial control technologies and perceptions of resulting products. Moreover, we find that providing information about the technology does not significantly alter respondent’s perception of most quality attributes.

Microbial Dynamics and Pathogen Control During Fermentation of Distiller Grains: Effects of Fermentation Time on Feed Safety

Determining the effects of fermentation duration on the microbial ecosystem, potential pathogenic risks, and metabolite generation during the fermentation of distilled grains is essential for safeguarding the safety and enhancing the nutritional profile of animal feed. This study investigates the effect of varying fermentation times (9, 30, and 60 days) on microbial diversity, pathogenic risk, and metabolite profiles in distiller grains using 16S rDNA sequencing and LC–MS-based metabolomics. The results showed that early fermentation (9–30 days) enhanced the abundance of beneficial bacteria, such as Lactobacillus reuteri and Lactobacillus pontis (p < 0.05), while pathogenic bacteria, like Serratia marcescens and Citrobacter freundii, were significantly reduced (p < 0.05). Metabolomic analysis revealed an increase in unsaturated fatty acids and the degradation of biogenic amines during early fermentation. However, prolonged fermentation (60 days) led to a resurgence of pathogenic bacteria and reduced the synthesis of essential metabolites. These findings suggest that fermentation duration must be optimized to balance microbial safety and nutrient quality, with 30 days being the optimal period to reduce pathogenic risks and enhance feed quality.

Isolation and identification of native Chilean entomopathogenic fungi and their potential for the control of Drosophila suzukii

Drosophila suzukii is an invasive pest of berries and other soft-skinned fruits, was first detected in Chile in 2017, and has since spread over 2,800 km from north to south. Sustainable control of the spotted-wing drosophila (SWD) is essential due the negative attitude of the consumers toward the excessive use of insecticides. During a survey in Chile for biological control agents, thirty-two isolates of entomopathogenic fungi (EPF) were isolated from mycotized insects and soil samples, identified through sequence analysis, and tested against D. suzukii adults under laboratory conditions. The EPF identified are Akanthomyces muscarius, Beauveria bassiana, Beauveria pseudobassiana, Clonostachys rosea, Metarhizium alvesii, Metarhizium brunneum and Metarhizium robertsii. Six isolates caused 100 % of mortality of D. suzukii adults within ten days after the initial exposition to conidia; these included four B. bassiana isolates (LSB 110, LSB 114, LSB 122 and LSB 125), one M. robertsii isolate (LSB 115) and one M. brunneum isolate (LSB 127). LSB 122 and LSB 125 induced the shortest lethal time (LT50 4 and 4.2 days, respectively), while Akanthomyces and Clonostachys caused ≤36 % cumulative mortality of the adults at 10 days of exposure. These results indicate that isolates of B. bassiana, M. robertsii and M. brunneum have significant potential as microbial control agents against D. suzukii adults. This study marks a critical step forward in identifying and validating native entomopathogenic fungi in Chile for sustainable pest management. Future work will focus on further testing these isolates under laboratory, semi-field and field conditions to optimize their application in real-world agricultural settings.

The impact of different concentrations of nano-capsulated Aleppo oak extraction on the biological performance of Amblyseius swirskii (Acari: Phytoseiidae)

Essential oils have demonstrated promising results in controlling mites. However, their impact on predatory mites, which are widely used in pest management programs, remains uncertain. In the present study, the effects of 1, 2 and 3 (g a.i. L-1) of nano-capsulated Aleppo oak extraction on the biological parameters of Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) were investigated under laboratory condition. Based on the results, the pre-adult period of the predator was significantly longer in the 2 (g a.i. L-1) concentration (6.66 days) compared with the control and the 1 (g a.i. L-1) concentration. Additionally, the total lifespan in the control group (39.42 days) was significantly longer than the treatment with a 3 (g a.i. L-1) concentration (31.50 days). The total fecundity in the 2 (g a.i. L-1) concentration (47.60 eggs/female) was significantly higher than the other treatments, indicating a positive effect of this botanical pesticide at the concentration recommended by the manufacturer on the reproductive system of the predatory mite. No significant differences were observed among the different treatments and the control group in terms of population growth parameters (GRR, R0, r, and λ). Only the mean generation time (T) showed a significant difference, with the longest period being recorded in the 2 (g a.i. L-1) concentration (15.44 ± 0.21), which was significantly longer than the control and the 1 (g a.i. L-1) concentration. The lack of significant differences in population growth parameters between the treatments indicates that nano-capsulated Aleppo oak extraction is safe for use along with the predatory mite A. swirskii.

Possibility for control with botanical insecticides against the mealy plum aphid Hyalopterus pruni Geoffroy, 1762 (Hemiptera: Aphididae) on the plum in Southern Bulgaria

The aim of this study was to evaluate the efficacy of botanical insecticides recommended for control of the mealy plum aphid Hyalopterus pruni (Hemiptera: Aphididae). The experiment was carried out in 2024 in the experimental field of the Fruit Growing Institute-Plovdiv, Bulgaria. The tested insecticides were orange oil (Limocid), liquid extract of Urtica spp. (Basictec) and pyrethrins (Abanto). The insecticides were applied at the recommended concentrations for control of aphids, whiteflies, thrips and other pests. All tested botanical insecticides showed high biological efficacy and can be used to control the mealy plum aphid. Keywords: mealy plum aphid, biological control, botanical insecticides, Limocid, Basictec, Abanto, Hyalopterus pruni

Evaluation of the insecticidal efficacy of four plants to protect stored Bambara groundnuts [Vigna subterranea (L.) Verdc. (Fabaceae)

Bambara groundnuts [Vigna subterranean] is one of the main legumes consumed in Northern Cameroon. However, stored nuts by farmers are quickly destroyed by pests leading to low yields. To overcome this constraint, the efficient control of stored grains from insect pests is dependent on synthetic insecticides. To reduce post-harvest losses of stored voandzou seeds, four botanicals insecticides have been developed and evaluated on the main pest. Plant powders prepared from Piper nigrum Linn. (Pipericaceae), Syzygium aromaticum (L.) Merr. & L.M.Perry (Myrtaceae), Xylopia aethiopica Dunal (Annonaceae) and Phaseolus vulgaris L.( Fabaceae), at different doses were tested on Callosobruchus maculatus Fabricius under laboratory conditions. The rest of the study involved combining black bean powder with the three condiment species in different proportions. The analysis shows a highly significant difference (p < 0.0001) between the mortality induced by formulations on day two of exposure with the lowest dose (0.5 g). These mortalities are 100%, 94.44 ± 3.79%, 72.5 ± 96 and 8.33 ± 4.77, respectively for S. aromaticum, P. nigrum, X. aethiopica and P. vulgaris powders. In relation to the formulation, the results show S. aromaticum powder induced 100% mortality compared with 94.44%, 72.59% and 8.33% respectively for P. nigrum, X. aethiopica and P. vulgaris plant powder at a dose of 5%. The results show that the natural substances used had a good insecticidal action against bruchid. The persistent compounds present in the studied spice plant powders are not toxic for human consumption at the concentrations used, but rather a beneficial effect. Key words: botanical insecticide, aromatic plants, powder, seeds, storage, insect pest.

Botanical extracts for insect management: lessons from participatory research in peri-urban horticultural systems of central Argentina

ABSTRACT We evaluate botanical insecticides as a technological device for synthetic input substitution in peri-urban horticultural system transitions. For that purpose, a Participatory Action Research (PAR) framework was proposed, and garlic extracts (GE) performance was evaluated for pest and natural enemy regulation in lettuce crops in conventional and agroecological contexts. Through three PAR cycles under actual production conditions, we observed GE effectiveness on aphids, thrips, and natural enemies. Additionally, context-specific adaptations were noticed: for conventional systems; the extract is useful near harvest and serves as a trust-building tool while reducing synthetic insecticide dependence. Instead, for agroecological systems, garlic extract highlighted biodiversity’s relevance for system redesign.

Multispecies Trichoderma in Combination with Hydrolyzed Lignin Improve Tomato Growth, Yield, and Nutritional Quality of Fruits

The application of biological pesticides as alternatives to chemical phytosanitary products is a natural and innovative method to improve environmental protection and sustainable agricultural production. In this work, the compatibility between Trichoderma spp. and a commercial lignin extract was assessed in vitro and in vivo. The beneficial effects of lignin in combination with different Trichoderma consortia were evaluated in terms of improved growth and quantitative and qualitative tomato productivity. T. virens GV41 + T. asperellum + T. atroviride + lignin formulation was the most effective in growth promotion and increased root and stem dry weight compared to control (45.4 and 43.9%, respectively). This combination determined a 63% increase in tomato yield compared to the control, resulting in the best-performing treatment compared to each individual constituent. Consistent differences in terms of lycopene, GABA, ornithine, total, essential, and branched-chain amino acids were revealed in fruits from tomato plants treated with Trichoderma–lignin formulations (T. asperellum + T. virens GV41 + lignin) or with the microbial consortia (T. asperellum + T. virens GV41, T. atroviride + T. virens GV41). The developed bioformulations represent a sustainable biological strategy to increase yield and produce nutritional compound-enriched vegetables.

Effect of Pipe Materials and Interspecific Interactions on Biofilm Formation and Chlorine Resistance: Turn Enemies into Friends

Drinking water distribution systems (DWDSs) may be contaminated to various degrees when different microorganisms attach to the pipe walls. Understanding the characteristics of biofilms on pipe walls can help prevent and control microbial contamination in DWDSs. The biofilm formation, interspecific interactions, and chlorine resistance of 10 dual-species biofilms in polyethylene (PE) and cast iron (CI) pipes were investigated in this paper. The biofilm biomass (heterotrophic bacterial plate count and crystal violet) of dual species in CI pipes is significantly higher than that in PE pipes, but the biofilm activity in CI pipes is significantly lower than that in PE pipes. The interspecific interaction of Sphingomonas-containing group presented synergistic or neutral relationship in PE pipes, whereas the interspecific interaction of the Acidovorax-containing group showed a competitive relationship in CI pipes. Although interspecific relationships may help bacteria resist chlorine, the chlorine resistance was more reliant on dual-species groups and pipe materials. In CI pipes, the Microbacterium containing biofilm groups showed better chlorine resistance, whereas in PE pipes, most biofilm groups with Bacillus exhibited better chlorine resistance. The biofilm groups with more extracellular polymeric substance (EPS) secretion showed stronger chlorine resistance. The biofilm in the PE pipe is mainly protected by EPS, while both EPS and corrosion products shield the biofilms within CI pipe. These results supported that dual-species biofilms are affected by pipe materials and interspecific interactions and provided some ideas for microbial control in two typical pipe materials.

Integrated pest management farmer field school of Chinese cabbage for young farmers in Batu City

The Abinaya Milenial Youth Farmers Group in Sumber Brantas Village, Bumiaji District, Batu City, faces significant challenges in cultivating Chinese cabbage due to a high incidence of clubroot disease caused by Plasmodiophora brassicae, with infection rates reaching 50–80 percent, leading to crop failure. The overuse of synthetic pesticides has resulted in pathogen resistance. Therefore, we adopted an integrated pest management (IPM) approach focusing on long-term prevention by integrating ecologically-based control techniques. The principles of IPM include managing healthy plants, preserving natural enemies, monitoring, and enhancing farmers' ecological understanding to become IPM experts. Through the IPM Farmer Field School (IPM-FFS), we aimed to implement ecological IPM, improve agroecosystem health, and support sustainable agriculture through participatory extension methods. Activities were conducted from June to November 2023 in Sumber Brantas Village, Bumiaji District, Batu City. The activities included surveys, planning, socialization, teaching, training, and follow-up. The IPM-FFS successfully developed standard operating procedures for Chinese cabbage management, increasing farmers' knowledge of IPM by 85 percent. The adoption of IPM reduced the incidence of clubroot disease to 20 percent, increased production by 420 kg, and reduced production costs by IDR 403,000 on an area of 400 m2. Farmers independently produce compost, compost tea, botanical pesticides, mycorrhizae, and fungicides through the IPM-FFS, empowering them in sustainable agriculture.

Optimization of fermentation conditions for Bacillus velezensis TCS001 and evaluation of its growth promotion and disease prevention effects on strawberries

Bacillus velezensis TCS001 is a novel biocontrol bacterium with broad-spectrum antifungal activity and plant growth-promoting effects, holding great potential for development in agricultural production. This study optimized the fermentation conditions for B. velezensis TCS001 through single-factor experiments combined with response surface methodology, and developed a formulation for TCS001 suspension concentrate (TCS001-SC). The efficacy of TCS001-SC to promote the growth of strawberries and to prevent and control strawberry anthracnose was evaluated. The optimal liquid fermentation condition for TCS001 was determined to be 2.89 % soluble peanut cake powder, 3.0 % glucose, 3.0 % soluble starch, 0.002 % FePO4, 0.006 % KCl, 0.6 % NaCl, 0.05 % MgCl2·6H2O, 0.3 % K2HPO4, 0.15 % KH2PO4, 0.05 % CaCO3, 0.005 % MnSO4, a working volume of 31 % (77.5 mL/250 mL), a rotation speed of 173 r/min, a cultivation temperature of 28°C, an inoculum volume of 1.0 %, and a pH of 7.0. The 15 L fermenter upscale culture achieved a spore count of 9.46 × 109 CFU/mL, which was 2.01 times the spore count of 4.7 × 109 CFU/mL before optimization, and a preliminary TCS001-SC was developed with the fermented broth as the main component. Agar plate confrontation tests showed that TCS001 had antifungal activity against five types of anthracnose fungi, with inhibition rates ranging from 70.3 % to 87.2 %. TCS001-SC could promote the growth of strawberries and induce a rapid defense enzyme response in their leaves, enhancing the plant's resistance to pathogens. After treatment, individual strawberry plants showed significant increases in the number of leaves, fresh weight of stems and leaves, root fresh weight, leaf area, plant height, and the content of POD, SOD, CAT enzymes, GA, IAA, and ABA compared to the control.Additionally, it shows good prevention and control effects against strawberry anthracnose, with a control efficacy of 60.45% after five spray treatments at a concentration of 2 × 107 CFU/mL, which is not significantly different from the efficacy of commercial microbial agents such as Bacillus subtilis wettable powder, subsequent field trials will be conducted to determine its potential as a microbial pesticide. This study provides important support for the future industrial production and application of the strain TCS001.

Making waves: Intelligent phage cocktail design, a pathway to precise microbial control in water systems

Current practices in water and wastewater treatment to control unwanted microbes have led to new problems, including health effects from disinfection byproducts, growth of opportunistic pathogens resistant to residual disinfectants (e.g., chlorine), and antibiotic resistance. These challenges are spurring interest in rethinking our practices of microbial control. Simultaneously, advances in molecular biology and computation power are driving renewed interest in using phages (viruses that infect bacteria) to precisely control microbial growth (aka, phage biocontrol). In this Making Waves article, I begin by reviewing the current state of research into phage cocktail design, emphasizing our limited understanding of the features of successful phage cocktails (combinations of multiple types of phages). I describe the state of modeling phage-bacteria interactions and underscore the need for increasing research efforts to predict phage cocktail success, a key gap slowing the application of phage biocontrol. I also detail how research must also focus on techniques for engineering more effective phages to offer a more rapid alternative to phage discovery from natural environments. In this way, phage cocktails comprised of phages with complementary infection strategies may be designed. The final area for increased research effort that I highlight is the need for phage cocktail design to account for possible unintended environmental effects, a risk that is increasingly acknowledged in phage ecology studies but mostly ignored by those developing phage biocontrol technologies. By focusing more research effort towards the areas necessary for intelligent phage cocktail design, we can accelerate the development of phage-based biocontrol in water systems and improve public health.

Development of a Triplex qPCR Assay Based on the TaqMan Probe for the Detection of Haemophilus parasuis, Streptococcus suis Serotype 2 and Pasteurella multocida

Porcine respiratory disease is a significant economic problem for the global swine industry. Haemophilus parasuis (H. parasuis), Streptococcus suis (S. suis), and Pasteurella multocida (P. multocida) are three important pathogenic bacteria of the swine respiratory tract. Notably, the three pathogens not only frequently manifest as mixed infections, but their striking clinical similarities also present difficulties for pig populations in terms of disease prevention and treatment. Thus, we developed a triplex real-time quantitative polymerase chain reaction (qPCR) assay based on a TaqMan probe for the detection of H. parasuis, S. suis serotype 2, and P. multocida. Primers and probes were designed to target the conserved regions of the H. parasuis OmpP2 gene, the S. suis serotype 2 gdh gene, and the P. multocida Kmt1 gene. By optimizing the reaction system and conditions, a triplex qPCR method for simultaneous detection of H. parasuis, S. suis serotype 2, and P. multocida was successfully established. The amplification efficiencies of the standard curves for all three pathogens were found to be highly similar, with values of 102.105% for H. parasuis, 105.297% for S. suis serotype 2, and 104.829% for P. multocida, and all R2 values achieving 0.999. The specificity analysis results showed that the triplex qPCR method had a strong specificity. The sensitivity test results indicated that the limit of detection can reach 50 copies/μL for all three pathogens. Both intra- and inter-assay coefficients of variation for repeatability were below 1%. This triplex qPCR method was shown to have good specificity, sensitivity, and reproducibility. Finally, the triplex qPCR method established in this study was compared with the nested PCR as recommended by the Chinese national standard (GB/T34750-2017) for H. parasuis, the PCR as recommended by the Chinese national standard (GB/T 19915.9-2005) for S. suis serotype 2, and the PCR as recommended by the Chinese agricultural industry standard (NY/T 564-2016) for P. multocida by detecting the same clinical samples. Both methods are reasonably consistent, while the triplex qPCR assay was more sensitive. In summary, triplex qPCR serves not only as a rapid and accurate detection and early prevention method for these pathogens but also constitutes a robust tool for microbial quality control in specific pathogen-free pigs.

INSECTICIDE SUSCEPTIBILITY IN TWO POPULATIONS OF Aedes aegypti L. (Diptera: Culicidae) FROM GUERRERO, MEXICO, AND RECOMMENDATIONS FOR THEIR MANAGEMENT

The Aedes aegypti L. mosquito is a vector of diseases such as classic and hemorrhagic dengue (DENV), chikungunya (CHIKV), Zika (ZIKV), yellow fever (YFV), and Mayaro (MAYV). In 2019 alone, in Latin America, there were 2.7 million cases and 1206 deaths. In Mexico, government programs for managing this pest include the elimination of larval habitats and chemical control of larvae and adults. The objective of this study was to evaluate the response of two larvae and adult populations of A. aegypti from the state of Guerrero, Mexico, under laboratory conditions, to insecticides with different modes of action and to make considerations for their management. In the bioassays, larvae showed susceptibility to permethrin, malathion, deltamethrin, and Bacillus thuringiensis var. israelensis; low resistance to Temephos and propoxur; as well as moderate resistance to Spinosad. Both adult populations showed resistance to permethrin and susceptibility to deltamethrin, while the Acapulco population showed resistance to alpha-cypermethrin. For larvae, Spinosad is suggested to be used in times of high incidence of dengue. During drought, it is advisable to include rotations of B. thuringiensis var. israelensis with organophosphates. For adults, the use of imidacloprid in combination with botanical insecticides is considered a rational alternative to rotations with organophosphates and pyrethroids.

Special issue: Botanical pesticides for crop protection

Special issue: Botanical pesticides for crop protection