Selective Insecticides Research Articles

Assessing agricultural practices and insecticides resistance for effective malaria vector control in northwestern Iran

BackgroundAfter three years with no local transmission of malaria, an outbreak occurred in Iran in 2022. Key malaria control methods in Iran are including indoor residual spraying (IRS), long-lasting insecticide-treated nets (LLINs), and prompt diagnosis and treatment of malaria cases. Anopheles sacharovi is one of the main malaria vectors in Iran. This study aimed to determine the insecticides resistance status of An. sacharovi in northwestern Iran, to inform effective vector control programs in this region.MethodsLarval stages of An. sacharovi were collected from various larval habitats located in the villages along the Aras River. Adult susceptibility tests were performed on An. sacharovi using diagnostic doses of insecticides accordance to World Health Organization (WHO) guidelines. The study also evaluated agricultural insecticide and fertilizer usage alongside the presence of natural mosquito predators in breeding sites in the study area.ResultsAlongside various chemicals such as silica, humic acid, superphosphate, sulfur, urea, and solupotasse at different dose levels, organophosphorus and pyrethroid insecticides are commonly used in rice fields and orchards. Anopheles sacharovi displayed diverse reactions to insecticides, demonstrating resistance to DDT but sensitivity to malathion, and showing similar reactions to carbamate and pyrethroid insecticides.ConclusionsThese results provide significant insights into agricultural practices and the presence of mosquito larvae in the study area. The extensive use of a specific herbicide illustrates its popularity among farmers for weed control, while other agricultural products focus on enhancing soil fertility and productivity. The absence of mosquito larvae in habitats with predators indicates the usefulness of these predators in controlling the population of mosquitoes. The resistance of mosquitoes to certain insecticides highlights the need for careful selection and intermittent use of insecticides in vector control programs. These findings can inform the development of targeted strategies to reduce malaria transmission risks. Further research is essential for assessing the effectiveness of these interventions.

Stability, Inheritance, Cross-Resistance, and Fitness Cost of Resistance to λ-Cyhalothrin in Cydia pomonella.

Insecticides are commonly utilized in agriculture and forestry for pest control, but their dispersal can pose hazards to humans and environment. Understanding resistance, inheritance patterns, and fitness costs can help manage resistance. A λ-cyhalothrin-resistant population (LCR) of Cydia pomonella, a global pest of pome fruits and walnuts, was obtained through selective insecticide breeding for 15 generations, showing stable moderate resistance (23.85-fold). This population was cross-resistant to deltamethrin (4.26-fold) but not to β-cypermethrin, chlorantraniliprole, chlorpyrifos, and avermectin. Genetic analysis revealed the resistance was autosomal, incompletely dominant, and controlled by multiple genes. Increased activity of glutathione S-transferases and cytochrome P450 monooxygenases (P450s) played a primary role in resistance, with specific genes up-regulated in LCR, and exhibited significant expression in midgut. LCR also exhibited fitness costs, including delays in development, reduced fecundity, and slower population growth. These findings contribute to understanding λ-cyhalothrin resistance in C. pomonella and can guide resistance management strategies.

Determining selectivity of isocycloseram and afidopyropen and their compatibility with conservation biological control in Arizona cotton.

Selective tools, including selective insecticides and transgenic cotton, have been crucial in reducing insecticide usage within the integrated pest management (IPM) plan for Arizona cotton. To guide growers effectively, cotton field trials evaluated the effects of the novel insecticides, isocycloseram and afidopyropen against our primary pests, Bemisia argentifolii and Lygus hesperus, and their impacts on nontarget arthropods, including key predators: Collops spp., Orius tristicolor, Geocoris spp., Misumenops celer, Drapetis nr. divergens and Chrysoperla carnea s.l. Assessments involved over 27 arthropod taxa through community analyses, individual predator abundance, and biological control function via predator to prey ratios and a sentinel prey method. Comparisons were made with an untreated check, a proven fully selective insecticide (flonicamid) and acephate-treated positive controls. Overall, relative to the untreated check, afidopyropen showed no significant differences, whereas isocycloseram exhibited some negative impacts, primarily reducing M. celer and Geocoris spp. nymphs, yet it was less detrimental compared with the positive control, acephate, and it did not affect four of the six key predators and most nontarget arthropods. Afidopyropen was classified as a fully selective insecticide and isocycloseram as a partially selective insecticide. Their fit for conservation biological control in Arizona cotton IPM and similar systems is discussed. © 2024 Society of Chemical Industry. Published by John Wiley & Sons Ltd.

Bioassay of Plant-based and Synthetic Insecticides for the Management of Tomato Leaf Miner, Tuta absoluta (Meyrick) in Open-field Conditions in Salyan, Nepal

The tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), has invaded most parts of Nepal and threatens tomato production. Their management primarily relies on insecticides in Nepal. Market-available and locally-madeplant-based pesticides are not equally effective in managingT. absoluta. Therefore, this study aimed to evaluate the effectiveness of such potential insecticides in managing T. absoluta in open-field conditions. This study was carried out in the Salyan district of Nepal in 2021 and treatments were designed in a randomized complete block design (RCBD)with seven treatments and three replications. All treatments were sprayed at12-dayintervalsfor two times. The treatments used were Emamect in benzoate 5% SC, Imidacloprid 17.8 SL, Jholmol (botanical mixture extract and urine mixture), Chlorantraniliprole 18.5 SC, Spinosad 45 SC, Azadirachtin 300ppm and Control. The results showed that the lowest percentage of leaves and fruit damage was recorded in Chlorantraniliprole 18.5 SC and Spinosad 45 SC sprayed plots. Insecticide efficiency was ranked as Chlorantraniliprole > Spinosad>Ema-mectin Benzoate > Azadirachtin >Imidaclroprid>Jholmol>Control. Marketable yield was obtained highest in Chlorantraniliprole (85.26 t/ha) treated plots followed by Spinosad (79.26 t/ha); both were not significantly different. This study provides an opportunity to select the most suitable and effective pesticides for the management of tomato leaf miners and can be used in integrated pest management strategies as a selective insecticides.

Laboratory Evaluation of the Combine Usage Possibilities of Entomopathogenic Nematodes with Insecticides against Mediterranean Corn Borer Sesamia nonagrioides (Lefebvre)

The Mediterranean Corn Borer (MCB), Sesamia nonagrioides, poses a significant threat to maize crops, necessitating effective pest management strategies. This study investigates the compatibility of two entomopathogenic nematode (EPN) isolates, Steinernema feltiae KV6 and Heterorhabditis bacteriophora EO7, with four registered insecticides for MCB control: deltamethrin, flubendiamide, spinetoram, and betacyfluthrin. The impact of these insecticides on EPN mortality, infectivity, and reproduction was assessed. Results indicate that deltamethrin exhibits the lowest toxicity to EPNs, with mortality rates of 1.3% for S. feltiae and 0.63% for H. bacteriophora at field dose (FD) after 24 h and 4.63% and 1.96%, respectively, after 48 h. In contrast, betacyfluthrin showed higher toxicity, with mortality rates of 38.04% and 14.17% for S. feltiae at 2FD and FD after 48 h. The infectivity assays demonstrated that deltamethrin-treated EPNs caused up to 100% mortality in MCB larvae, while the reproduction capacity varied significantly between the EPN species and insecticides. H. bacteriophora exhibited higher progeny production, especially in the presence of deltamethrin (87,900 IJs/larva). The findings suggest that integrating EPNs with selective insecticides like deltamethrin can enhance pest control efficacy and support sustainable agricultural practices. This study provides valuable insights for developing integrated pest management (IPM) strategies aimed at mitigating MCB infestations in maize while minimizing environmental impacts.

Lethal and sublethal effects of spinosad on dengue vector mosquito, Aedes albopictus and bancroftian filariasis vector mosquito, Culex pipiens pallens.

Aedes albopictu and Culex pipiens pallens are important vectors of many viruses and have had resistance to chemical pesticide. Spinosad is a selective biological insecticide to control urban mosquito. The aim of this study was to reveal the sublethal effects of spinosad on mosquito and provide reference basis for integrated mosquito management. The toxicity of spinosad against Ae. albopictus and Cx. pipiens pallens were determined under laboratory conditions by exposing early third-instar larvae to different concentrations. The LC50 values of spinosad to Ae. albopictus and Cx. Pipiens pallens larvaes were 4.44×10-3 mg∙L-1 and 1.93×10-3 mg∙L-1 respectively after 72 h exposure. Spinosad at sublethal concentrations has many negative effects on Ae. albopictus and Cx. Pipiens pallens larval, pupae, adult and offspring eggs, including significantly reduced their larvae pupation rate by 51.37% and 58.47%, significantly prolonged pupae length by 21.43% and 16.18%, reduced female wing-spans by 20.19% and 14.89%, reduced male wing-spans by 3.84% and 7.54%, reduced female weight by 29.04% and 31.52%, reduced male weight by 7.47% and 9.07%, reduced female and male ratio by 51.98% and 45.21%, reduced individual egg-laying amount by 15.73% and 35.51%, in addition, offspring egg hatchability were dramatically decreased by 25.71% and 34.04%, egg periods were significantly prolonged by 14.42% and 62.82% respectively. No significant effect on larval period, pupae emergence rate, female bite rates were observed. These results suggest that spinosad might affect pest population dynamics significantly and is fairly expected to be a candidate biological pesticide for mosquito control.

Realized heritability, inheritance, and mechanism of chlorfenapyr resistance in biocontrol agent, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae): A step towards sustainable pest management

A field population of Chrysoperla carnea was exposed for 17 generations to chlorfenapyr insecticide that resulted in 217-fold resistance compared to a susceptible strain. The overlapping of LC50 values in reciprocal crosses and their dominance values indicated that chlorfenapyr resistance was autosomal and incompletely dominant. The chi-square analysis of back-cross mortality confirmed the polygenic nature of chlorfenapyr resistance. The results of effective dominance of chlorfenapyr resistance indicated that resistance at the highest concentration was completely recessive. The realized heritability of chlorfenapyr resistance in the first 9, last 9, and a total of 18 generations was 0.28, 0.42, and 0.31, respectively. Furthermore, synergism results showed that both experimental synergists, PBO and DEF, did not synergize the toxicity of chlorfenapyr. In conclusion, C. carnea had been found to have autosomal, partially dominant, and polygenic chlorfenapyr resistance. Meaning that thereby resistance is inherited through multiple genes and is not limited to a single gene or sex-linked trait. These findings will help to develop an effective IPM model focusing on the simultaneous use of selective insecticides and resistant biocontrol agents to reduce the problem of resistance development in pest populations.

Theory versus practice: are insecticide mixtures in Arizona cotton used for resistance management?

Resistance management in pesticide use is critical, yet grower practices, especially pesticide mixing motivations, diverge from theoretical frameworks. This study analyzes 30 years of Arizona cotton growers' practices and pest manager insights to understand mixing trends. Growers predominantly mix pesticides for spectrum or efficacy, not resistance management. This highlights a gap between theory and practice, emphasizing the complexity of real-world dynamics. A shift over time towards selective insecticides and integrated pest management (IPM), supported by extension education, has reduced reliance on broad-spectrum insecticides and increased opportunities to conserve the natural enemies of key pests. This reduced the frequency of insecticide use, a mutual goal of both IPM and resistance management. The availability and adoption of selective products with diverse modes of action, along with the resulting increases in biological control and refuges, likely has delayed or prevented resistances without emphasis on using mixtures specifically for resistance management. In a disrupted system exclusively dependent on broad-spectrum insecticides (1991-1995), 75% ± 5% of cotton area was sprayed with mixtures of these materials. With the availability of selective insecticides, few broad-spectrum products are used today and mixtures of insecticides are sprayed on only 36% ± 3% of the cotton area (2015-2020). Although mixing has theoretical relevance, it is diminishing in stable systems with diverse modes of action and adherence to moderation principles. Arizona cotton guidance prioritizes multi-crop refuges over mixtures for resistance management. Integrated research and education, targeting professional pest managers, are pivotal in advancing resistance management without mixtures specifically designed to prevent or mitigate resistance. © 2024 Society of Chemical Industry.

Compatibility of Bioinsecticides with Parasitoids for Enhanced Integrated Pest Management of Drosophila suzukii and Tuta absoluta.

Drosophila suzukii and Tuta absoluta are successful biological invaders of agroecosystems. Their integrated pest management (IPM) programs involve the release and/or conservation of natural enemies. Among these, Ganaspis kimorum is a major Asian parasitoid of D. suzukii and has been introduced as a classical biological control agent of this pest in Europe and North America, while Necremnus tutae is a key fortuitous parasitoid of T. absoluta in the Mediterranean region. Bioinsecticides represent key alternatives to chemicals for controlling both pests. This study investigated the potential compatibility of both parasitoids with Beauveria bassiana, Bacillus thuringiensis, garlic essential oil (EO), and spinosad, in comparison to two synthetic insecticides, cyantraniliprole and chlorantraniliprole. The results showed that combining each of the tested insecticides with G. kimorum slightly increased pest mortality compared to the insecticide alone. Necremnus tutae had a significant additive effect on host mortality when combined with insecticides. Beauveria bassiana and B. thuringiensis were most compatible with both parasitoid species. Both garlic EO and chlorantraniliprole impaired the survival of immature N. tutae and showed sublethal toxicity on the reproductive and non-reproductive behaviors of N. tutae. Spinosad exhibited high acute toxicity on both juvenile and adult parasitoids of both species. Overall, these findings provide useful insights into insecticide selectivity toward two key parasitoids and offer new knowledge on the potential of combining natural enemies and bioinsecticides for optimized IPM.

Interaction of fluralaner with binary model membranes. Potential implications in the selectivity for invertebrates/vertebrates

GABAA receptors (GABAA-R) are the target of widely used gabaergic insecticides such as fluralaner, a second generation non-competitive antagonist. Fluralaner blocks GABAA-R, binding to a pocket in the transmembrane subunit interface. Because of the location of its binding pocket, it is expected that fluralaner accesses to the receptor by previously partitioning into the bilayer. Therefore, differences in lipid composition of insect and mammal cells become relevant to determine the impact of membrane composition on the nonspecific selectivity of gabaergic insecticides. Insect cells show minimal concentration of cholesterol and they modulate membrane fluidity by regulating PE:PC ratios. On the other hand, vertebrate cholesterol concentration can be as high as 50%, depending on the type of cell. We used experimental Langmuir monolayer and Molecular Dynamics Simulations (MDS) to characterize the effect and interactions of the insecticide fluralaner with model membranes with varying concentrations of POPC:POPE and POPC:CHOL. Monolayer experiments showed that this insecticide reduces film rigidity. MDS showed that fluralaner is located at the interface between the acyl chain and the polar region of the membrane, but this location shifts at high CHOL concentrations towards the phosphate region. This is accompanied by a shift in the orientation of the fluralaner backbone, affecting fluralaner solubility. The presence of CHOL favors fluralaner aggregation, while POPE has the opposite effect, allowing its solubilization and the presence of individual insecticide molecules homogeneously dispersed. Our work suggests that differences in membrane composition could unspecifically influence the selectivity of gabaergic insecticides, modulating fluralaner solubility and fluralaner's access to GABAA-R.

Comparative bio-efficacy of different insecticides on major sucking pests of Bt-cotton

The field evaluation of various insecticides on major sucking pests of Bt-cotton during the 2022-23 season demonstrated significant reductions in pest occurrence across all treatments compared to the control. However, the efficacy varied depending on the insecticide used. Among all the treatments, Flonicamid 50 WG proved highly effective in managing all the sucking pests by recording lowest incidence of thrips (8.44/ 3 leaves), leaf hopper (5.43/ 3 leaves), aphid (3.64/ 3 leaves) and whitefly (3.29/ 3 leaves) with highest cotton yield (19.41 q/ha), net returns (53,540 `/ha) and B: C ratio (1.85) as compared to all other treatments. In addition, other promising alternatives such as Dinotefuran 20 SG, Spinetoram 11.7 SC, and Diafenthiuron 50 WP for combating thrips, Dinotefuran 20 SG and Spinetoram 11.7 SC for addressing leaf hoppers, and Pyriproxyfen 10 EC, Diafenthiuron 50 WP, and Dinotefuran 20 SG can be utilized for managing aphids and whiteflies in Bt- cotton. Utilizing these findings to optimize the selection and application of insecticides can enable growers to more effectively control pest pressures, thereby enhancing both the productivity and quality of Bt-cotton crops. Overall, Flonicamid 50 WG emerged as the most cost-effective option, underscoring its potential as a key solution for managing sucking pests in Bt-cotton cultivation.

Impact and selectivity of insecticides on groundnut predators

Impact and selectivity of insecticides on groundnut predators

Compatibility Studies on Selective Insecticides, Fungicides and Water-Soluble Fertilizer Mixtures in Soybean

In present context, there is a demand for combination spray of insecticides and fungicides to manage both insect pests and diseases simultaneously in a crop season. However, tank mixing of incompatible combinations can reduce the effectiveness of the chemicals, cause phytotoxicity or development of insecticide resistance in pests. Hence, a laboratory experiment was conducted at Agricultural Research Station (UAS, Dharwad), Sankeshwar, Karnataka to study the physical, chemical and phytotoxic compatibility of selective insecticides, fungicides and water-soluble fertilizer mixtures at their recommended dose in soybean by jar compatibility method. Out of eighteen different combinations tested emamectin benzoate 5 SG (0.3 g l-1) in combination with propiconazole 25 EC (1 ml l-1) and 19:19:19 (N:P:K @ 5 g l-1), as well as lambda cyhalothrin 4.6 + chlorantraniliprole 9.3 ZC (0.4 ml l-1) in combination with propiconazole 25 EC (1 ml l-1) and 19:19:19 (5 g l-1) exhibited sedimentation levels of 1 ml l-1 which was less than the limits of 2 ml 100 ml-1 as specified in 1973 by Indian Standard Institute. The pH of agrochemicals both alone and combinations in all solutions test ranged from 6.02 to 8.39 and none of the solutions found extremely acidic nor alkaline. No phytotoxic symptoms were observed in combination treatments at 5 and 10 days after spraying. All test combinations were physically, chemically and biologically compatible hence, tank mixing of these chemicals can be recommended in soybean for managing of insect pest and diseases.

Field evaluation of whorl application of sand mixed or spray insecticides against Spodoptera frugiperda (Lepidoptera: Noctuidae) on yield of maize

BackgroundSpodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), the fall armyworm (FAW), has recently invaded Egypt and poses serious threats to maize farmers as it causes huge economic costs and yield losses. Selection of efficient insecticides and appropriate methods of application can be a problem to control this pest.MethodsTwo-year field studies to effectiveness of whorl application (sand mixed or spray) of seven insecticides comprising new insecticides generations with conventional insecticides from different groups at maximum recommended dosage field rate against FAW on yield of maize was evaluated in maize fields at El-Qualubia Governorate, Egypt.ResultsIn plots treated with insecticide mixed in sand, all tested insecticides recorded a significant decrease in FAW larvae with significantly higher yields than those treated with spraying or untreated plots. However, among tested insecticides in both applications, chlorantraniliprole was found to be the most effective followed by emamectin benzoate and spinosad and these insecticides gave better control FAW with higher yield than conventional insecticides tested. In this context, the highest decrease in FAW density was recorded in plots treated with chlorantraniliprole mixed in sand or sprayed (93.69% for 2021; 91.59% for 2022) and (84.74% for 2021; 85.78% for 2022), respectively, as well as a significantly high yield. However, lambda-cyhalothrin recorded the highest density of FAW (33.86% for 2021; 32.72% for 2022) in the treated plots with spraying with lowest significant yield during the 2021 and 2022 seasons in the treated plots with spraying by 8.98 and 8.00%, respectively, increase over control plots.ConclusionsThese results indicate that insecticides mixed in sand application are more efficacious against FAW larvae along with yield increase than spraying.

Computational study on organochlorine insecticides extraction using ionic liquids

Insecticides pose hazardous environmental effects and can enter the food chain and contaminate water resources. Ionic liquids (ILs) have recently drawn much interest as environmentally friendly solvents and have been an efficient choice for extracting pesticides because of their outstanding thermophysical characteristics and tunable nature. In this study, ILs were screened using COSMO-RS (Conductor-like Screening Model for Real Solvents) to extract organochlorine insecticides from water at 289 K. A total of 165 ILs, a combination of 33 cations with five anions, were screened by COSMO-RS to predict the selectivity and capacity of the organochlorine insecticides at infinite dilution. The Organochlorine insecticide compounds, such as benzene hexachloride (BHC), Heptachlor, Aldrin, Gamma-Chlordane (γ-Chlordane), Endrin, and Methoxychlor are selected for this study. Charge density profiles show that Endrin and Methoxychlor compounds are strong H-bond acceptors and weak H-bond donors, while the rest of the compounds are H-bond donors with no H-bond acceptor potential. Moreover, it has been shown that ILs composed of halides and heteroatomic anions in conjunction with cations have enhanced selectivity and capacity for insecticides. Moreover, the hydrophobic phosphonium-based ILs have enhanced selectivity and capacity for insecticides. In BHC extraction, the selectivity of 1,3-dimethyl-imidazolium chloride was found to be the highest at 1074.06, whereas 2-hydroxyethyl trimethyl ammonium chloride exhibited the highest capacity being 84.0.1,3-dimethyl-imidazolium chloride exhibits the highest performance index, which is 57064.77. In addition, the ILs that have been chosen are well-recognized as environmentally friendly and very effective solvents to extract insecticides from water. As a result, this study evaluated that ILs could be promising solvents that may be further developed for the extraction of insecticides from contaminated water.

Assessing the sub‐lethal impacts of insecticides on aphid parasitoids through laboratory‐based studies

AbstractAphids are a major pest of cropping systems throughout the world. In most cases, crop aphids are controlled with broad‐spectrum insecticides; although generally very effective at preventing yield loss, this approach risks non‐target damage to beneficial organisms. In the last 20 years, a number of selective insecticides have become available to control aphids while minimising harm to other arthropods. Previous studies have found that two such insecticides, flonicamid and afidopyropen, cause only low‐level acute mortality impacts on aphid parasitoids in Australian grain crops. However, little research has examined the sub‐lethal effects of these chemicals, which could induce various physiological changes that impact pest control. We hypothesised that both flonicamid and afidopyropen have negative effects that extend beyond the immediate acute mortality previously published. To test this hypothesis, we undertook a series of experiments to determine the effects of flonicamid and afidopyropen, along with the synthetic pyrethroid gamma‐cyhalothrin, on aphid parasitism (mummification) rate, emergence rate of the next generation and the next generation sex ratio in three important aphid parasitoids, Aphidius colemani (Viereck), Diaeretiella rapae (M'Intosh) and Aphelinus abdominalis (Dalman). Analogous with previous research, our acute toxicity bioassays showed that all three insecticides had low (<30%) mortality impacts. Although sub‐lethal impacts could not be assessed for D. rapae due to the low level of aphid parasitism by that species, our findings showed negative impacts on fecundity in surviving A. abdominalis and A. colemani. Of particular note is the increase in International Organisation for Biological Control ratings to moderate (30%–80% mortality and/or reproductive reduction) when mortality and reduced fecundity effects were combined to determine overall fitness impacts. Gamma‐cyhalothrin typically resulted in higher negative impacts on A. abdominalis and A. colemani (compared with flonicamid and afidopyropen); however, quite surprisingly, these impacts were not rated as highly toxic. Taken together, our results suggest that, even when sub‐lethal impacts are considered, flonicamid and afidopyropen are useful tools for farmers targeting aphid populations while minimising the non‐target impacts on parasitoids. We recommend semi‐field and/or field trials to further assess the impacts of these insecticides on aphid parasitoid populations.

Laboratory and simulated semi-field larvicidal efficacy of Aframomum angustifolium (Sonn.) K. Schum and Tagetes patula essential oils against Anopheles gambiae

IntroductionMalaria is a vector-borne, important public health problem spread by mosquitoes in tropical regions. The use of synthetic insecticides for mosquito control has been linked to insecticide resistance and environmental consequences. Thus, there is an urgent need to search for new highly selective and biodegradable insecticides lacking long-term toxicity to humans and mammals which are botanical-based compounds from indigenous plant sources available in local communities. Therefore, this study focused on evaluating the larvicidal activity of Aframomum angustifolium and Tagetes patula essential oils against Anopheles gambiae larvae in laboratory and simulated fields. MethodsThe Eos was extracted by the hydro distillation method, and the chemical composition of the Eos was determined using gas chromatography-mass spectrometry (GC-MS). The WHO protocol was followed for the laboratory and the simulated bioassays. Both laboratory-reared and field-collected larvae, as well as non-targeted organisms (Gambusia affinis), were used in simulated field conditions. The collected data were analyzed using probit analysis, and their means were compared in one-way analysis of variance (ANOVA) using IBM SPSS Statistic version 26. ResultsThe main active ingredients in T. patula Eo were terpinolene (20.75 %) and (Z)-ocimene (17.10 %) and A. angustifolium were cis-pinen-3-ol (58.48 %) β-pinene (31.03 %). The EO of T. patula was the most efficacious in the bioassay. The larvicidal bioassay findings demonstrated that the mortality rate was dose- and exposure-dependent. In the laboratory, the EOs of A. angustifolium and T. patula have larvicidal activity against An. gambiae larvae, with LC50 values of 1.71 and 0.71 ppm after 48 h, respectively. Both binary combinations of the EOs showed synergistic interactions at 24 h but antagonistic interactions at 48 h. In the simulated field trial using laboratory-reared larvae, the mortality rate was higher in the simulated setting compared with the laboratory setting for all the tested concentrations for both EOs. Only A. angustifolium EO was toxic against Gambusia affins at 100 ppm. ConclusionThe findings of this study have shown that T. patula and A. angustifolium oils have good larvicidal activities for An. gambiae. The two plants are potential sources of larvicidal compounds that could be used to control the malaria vector.

Influence of select foliar insecticides on soybean looper management in soybeans I, 2022

Influence of select foliar insecticides on soybean looper management in soybeans I, 2022

Spinetoram, a Selective Novel Insecticide Able to Check Key Lepidopteran Pests in Cabbage Ecosystem

Spinetoram, a Selective Novel Insecticide Able to Check Key Lepidopteran Pests in Cabbage Ecosystem

Influence of select foliar insecticides on soybean looper management in soybeans II, 2022

Influence of select foliar insecticides on soybean looper management in soybeans II, 2022