Mosquitoes are major vectors for the transmission of many diseases like chikungunya, malaria, dengue, zika, etc. worldwide. In the present study, selenium nanoparticles (SeNPs) were synthesized from Clausena dentata and were tested for their larvicidal efficacy against the fourth-instar larvae of Anopheles stephensi, Aedes Aegypti, and Culex quinquefasciatus. The synthesized nanoparticles were characterized using UV-Vis spectroscopy, Fourier Transform Infrared Radiation (FTIR) spectroscopy, EDaX, and SEM. The results recorded from UV-Vis spectroscopy show the peak absorption spectrum at 420 nm. In FTIR, the maximum peak value is 2922.25 cm assigned to N-H group (amide group). In EDaX analysis shows peak around 72.64 which confirm the binding intensity of selenium. In SEM analysis, the synthesized SeNPs sizes were ranging from 46.32 nm to 78.88 nm. The synthesized SeNPs produced high mortality with very low concentration (LC) were 240.714 mg/L; 104.13 mg/L, and 99.602 mg/L for A. stephensi, A. Aegypti, and C. quinquefasciatus, respectively. These results suggest that the C. dentata leaf extract-mediated biosynthesis of SeNPs has the potential to be used as an ideal ecofriendly approach toward the control of mosquito vectors at early stages.

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Botanical metabolites are increasingly realized as potential replacements to chemical insecticides. In the present study, Acacia nilotica seed essential oil and seed pod solvent extracts were tested for bioefficacy against three important types of mosquitoes. Mortality was recorded 24 h post-treatment, while smoke toxicity of adult mosquitoes was recorded at 10 min intervals for 40 min. Seed pod powder was extracted with different solvents and hydrodistilled seed oil chemical constituents were determined by using Gas chromatography mass spectroscopy (GC-MS) -. Larvicidal and adulticidal efficacy of seed hydrodistilled essential oil and solvent extracts were tested against larval and adult mosquitoes. The seed hydrodistilled oil provided strong larvicidal activity against Anopheles stephensi, (LC50 (lethal concentration that kills 50% of the exposed larvae) = 5.239, LC90 (lethal concentration that kills 90% of the exposed larvae) = 9.713 mg/L); Aedes aegypti, (LC50 = 3.174, LC90 = 11.739 mg/L); and Culex quinquefasciatus, (LC50 = 4.112, LC90 = 12.325 mg/L). Smoke toxicities were 82% in Cx. quinquefasciatus, 90% in Ae. aegypti, and 80% mortality in An. stephensi adults, whereas 100% mortality was recorded for commercial mosquito coil. The GC-MS profile of seed essential oil from A. nilotica showed the presence of hexadecane (18.440%) and heptacosane (15.914%), which are the main and active compounds, and which may be involved in insecticidal activity. Overall findings suggest that the seed oil showed strong mosquitocidal activity against mosquito vectors and therefore may provide an ecofriendly replacement to chemical insecticides.

Mosquito vectors are responsible for the transmission of parasitic and viral infections, including loss in commercial and labor outputs, particularly in developing countries with tropical and subtropical climates. The aim of the present study is to evaluate the adulticidal and smoke toxicity of Cipadessa baccifera (Roth) against three important mosquitoes vectors, Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus (Diptera: Culicidae). Adult mortality was observed after 24-h recovery period. The plant crude extracts showed dose-dependent mortality. At higher concentrations, the adult showed restless movement for some times with abnormal wagging and then died. Among the extracts tested, the highest adulticidal activity was observed in acetone extract against An. stephensi followed by Ae. aegypti and Cx. quinquefasciatus with the LD50 and LD90 values 16.021 (14.080-18.345), 29.095 (25.118-34.089); 23.581 (22.100-28.315), 38.636 (35.321-41.021); and 13.560 (9.479-17.391), 248.35 (203.47-344.43) mg/ml, respectively. No mortality was recorded in the control. Smoke toxicity was observed at 10-min interval for 40 min and the mortality data were recorded. Among the C. baccifera plant powder tested. Smoke toxicity results show that Cx. quinquefasciatus, An. stephensi, and Ae. aegypti shows 88.6 ± 1.8, 78.2 ± 0.5, and 77 ± 1, respectively. One hundred percent mortality was recorded in the commercial mosquito control. The present study shows that C. baccifera leaf powder can be used as an efficient toxicity against mosquitoes. These results suggest that the leaf extracts of C. baccifera have a potential to be used as an ideal eco-friendly approach for the control of mosquitoes.

Resistance of mosquitoes to insecticides is a growing concern in India. Since only a few insecticides are used for public health and limited development of new molecules is expected in the next decade, maintaining the efficacy of control programs mostly relies on resistance management strategies. Developing such strategies requires a deep understanding of factors influencing resistance together with characterizing the mechanisms involved. Among factors likely to influence insecticide resistance in mosquitoes, agriculture and urbanization have been implicated but rarely studied in detail. In the present study, we evaluate the permethrin resistance and cross-resistance pattern of several insecticides in Culex quinquefasciatus mosquitoes. After 10 generation of selection with permethrin, the LC50 value for both larvae and adult Cx. quinquefasciatus was increased by 17.3- and 17.1-folds compared with susceptible strain. Detoxification enzyme profiles and native PAGE electrophoresis of esterase isoenzyme further revealed that esterase and CytP450 may be involved in permethrin resistance (PerRes) strain compared with susceptible strain. In addition to cross-resistance, study revealed that high resistance to cypermethrin (RR = 6.3, 8.8-folds). This study provided important information for understanding permethrin resistance and facilitating a better strategy for the management of resistance. These studies conclude that a strong foundation for further study of permethrin resistance mechanisms observed in Cx. quinquefasciatus mosquitoes.

Mosquitoes in the larval stage are attractive targets for pesticides because mosquitoes breed in water, and thus, it is easy to deal with them in this habitat. The use of conventional pesticides in the water sources, however, introduces many risks to people and/or the environment. Natural pesticides, especially those derived from plants, are more promising in this aspect. Aromatic plants and their essential oils are very important sources of many compounds that are used in different respects. Insecticides of botanical origin may serve as suitable alternative to chemical insecticides. Acetone, chloroform, ethyl acetate, methanol, and petroleum benzine leaf extracts of Clausena dentata were tested against the fourth instar larvae of Anopheles stephensi, Culex quinquefasciatus, and Aedes aegypti (Diptera: Culicidae). Larval mortality was observed after 24 h of exposure. The highest larval mortality was found in acetone leaf extract, C. quinquefasciatus (LC50 = 0.150278 mg/ml; LC90 = 7.302613 mg/ml), A. aegypti (LC50 = 0.169495 mg/ml; LC90 = 1.10034 mg/ml), and A. stephensi (LC50 = 0.045684 mg/ml; LC90 = 0.045684 mg/ml). GC-MS analysis of plant extracts of acetone solvent revealed 16 compounds, of which the major compounds were benzene,1,2,3-trimethoxy-5-(2-propenyl) (14.97%), Z,Z-6,28-heptatriactontadien-2-one (6.81%), 2-allyl-4-methylphenol (28.14%), 2-allyl-4-methylphenol (17.34%), and 2,6,10,14,18,22-tetracosahexaene, 2,6,10,15,19,23-hexamethyl (10.35%). Our result shows acetone leaf extracts of C. dentata have the potential to be used as an ideal eco-friendly approach for mosquito control.

Mosquito control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of botanical origin may serve as suitable alternative biocontrol agents. The present study is to evaluate adulticidal activity of Clausena dentata plant extract against Aedes aegypti and Culex quinquefasciatus mosquitoes. The adult mortality was observed after 24 h of exposure. The highest mortality was found in acetone extracts against Ae. aegypti and Cx. quinquefasciatus with the LC50 and LC90 4.1783 mg/ml (3.8201-7.1026), 9.3884 mg/ml (7. 8258-13.1820) and 4.2451 mg/ml (3.8547-8.0254), 12.3214 mg/ml (10.9287-16.2220), respectively. Smoke toxicity was observed at 10-min interval for 40 min, and the mortality data were recorded. Result shows that Ae. aegypti and Cx. quinquefasciatus are 85 ± 2 and 89 ± 1.5, respectively. A mortality of 100 % was recorded in the commercial mosquito control. These results suggest that the leaf extracts of C. dentata have a potential to be used as an ideal eco-friendly approach for the control of mosquitoes.

Genome‐wide analysis of cytochrome P450 monooxygenase (CYP) genes from the advanced genome project of the Leucinodes orbonalis and the expression analysis provided significant information about the metabolism‐mediated insecticide resistance. A total of 72 putative CYP genes were identified from the genome and transcriptome of L. orbonalis. The genes were classified under 30 families and 46 subfamilies based on the standard nomenclature. In the present study, a novel CYP gene, CYP324F1, was identified and it has not been reported from any other living system so far. Biochemical assays showed enhanced titers (5.81–18.5‐fold) of O‐demethylase of CYP in five field‐collected populations. We selected 34 homologous CYP gene sequences, seemed to be involved in insecticide resistance for primer design and quantitative real‐time PCR studies. Among the many overexpressed genes (>10 fold), the expression levels of CYP324F1 and CYP306A1 were prominent across all the field populations as compared with the susceptible iso‐female line. Oral delivery of ds‐CYP324F1 and ds‐CYP306A1 directed against CYP324F1 and CYP306A1 to the larvae of one of the insecticide resistance populations caused reduced expression of these two transcripts in a dose‐dependent manner (53.4%–85.0%). It appears that the increased titer of O‐demethylase is the result of increased transcription level of CYP genes in resistant populations. The data provide insight for identifying the novel resistance management strategies against L. orbonalis.