Mosquito larvicidal activity of gluanol acetate, a tetracyclic triterpenes derived from Ficus racemosa Linn

Sialic acids as attachment factors in mosquitoes mediating Japanese encephalitis virus infection

The role of Culex mosquitoes in the transmission of Japanese encephalitis virus (JEV) is crucial, yet the mechanisms of JEV infection in these vectors remain unclear. Previous research has indicated that various host factors participate in JEV infection. Herein, we present evidence that mosquito sialic acids enhance JEV infection both in vivo and in vitro. By treating mosquitoes and C6/36 cells with neuraminidase or lectin, the function of sialic acids is effectively blocked, resulting in significant inhibition of JEV infection. Furthermore, knockdown of the sialic acid biosynthesis genes in Culex mosquitoes also leads to a reduction in JEV infection. Moreover, our research revealed that sialic acids play a role in the attachment of JEV to mosquito cells, but not in its internalization. To further explore the mechanisms underlying the promotion of JEV attachment by sialic acids, we conducted immunoprecipitation experiments to confirm the direct binding of sialic acids to the last α-helix in JEV envelope protein domain III. Overall, our study contributes to a molecular comprehension of the interaction between mosquitoes and JEV and offers potential strategies for preventing the dissemination of flavivirus in natural environments.IMPORTANCEIn this study, we aimed to investigate the impact of glycoconjugate sialic acids on mosquito infection with Japanese encephalitis virus (JEV). Our findings demonstrate that sialic acids play a crucial role in enhancing JEV infection by facilitating the attachment of the virus to the cell membrane. Furthermore, our investigation revealed that sialic acids directly bind to the final α-helix in the JEV envelope protein domain III, thereby accelerating virus adsorption. Collectively, our results highlight the significance of mosquito sialic acids in JEV infection within vectors, contributing to a better understanding of the interaction between mosquitoes and JEV.

Neem-based products as potential eco-friendly mosquito control agents over conventional eco-toxic chemical pesticides-A review

Mosquitoes cause serious health hazards for millions of people across the globe by acting as vectors of deadly communicable diseases like malaria, filariasis, dengue and yellow fever. Use of conventional chemical insecticides to control mosquito vectors has led to the development of biological resistance in them along with adverse environmental consequences. In this light, the recent years have witnessed enormous efforts of researchers to develop eco-friendly and cost-effective alternatives with special emphasis on plant-derived mosquitocidal compounds. Neem oil, derived from neem seeds (Azadirachta indica A. Juss, Meliaceae), has been proved to be an excellent candidate against a wide range of vectors of medical and veterinary importance including mosquitoes. It is environment-friendly, and target-specific at the same time. The active ingredients of neem oil include limonoids like azadirachtin A, nimbin, salannin and numerous other substances that are still waiting to be discovered. Of these, azadirachtin has been shown to be very effective and is mainly responsible for its toxic effects. The quality of the neem oil depends on its azadirachtin content which, in turn, depends on its manufacturing process. Neem oil can be used directly or as nanoemulsions or nanoparticles or even in the form of effervescent tablets. When added to natural breeding habitat waters they exert their mosquitocidal effects by acting as ovicides, larvicides, pupicides and/or oviposition repellents. The effects are generated by impairing the physiological pathways of the immature stages of mosquitoes or directly by causing physical deformities that impede their development. Neem oil when used directly has certain disadvantages mainly related to its disintegration under atmospheric conditions rendering it ineffective. However, many of its formulations have been reported to remain stable under environmental conditions retaining its efficiency for a long time. Similarly, neem seed cake has also been found to be effective against the mosquito vectors. The greatest advantage is that the target species do not develop resistance against neem-based products mainly because of the innumerable number of chemicals present in neem and their combinations. This makes neem-based products highly potential yet unexplored candidates of mosquito control agents. The current review helps to elucidate the roles of neem oil and its various derivatives on mosquito vectors of public health concern.

Xanthotoxin: an aphicidal coumarin from Ficus petiolaris against Melanaphis sacchari Zehntner (Hemiptera: Aphididae)

In this research, we evaluated the aphicidal effect of the ethanolic extract of stems and bark of Ficus petiolaris Kunth (Moraceae), in laboratory bioassays in an artificial diet against apterous adult females of Melanaphis sacchari Zehntner (Hemiptera: Aphididae). The extract was evaluated at different concentrations (500,1,000,1,500,2,000,and2,500ppm), and the highest percentage of mortality (82%) was found at 2,500 ppm after 72 h. The positive control imidacloprid (Confial®) at 1% eliminated 100% of the aphids, and the negative control (artificial diet) only presented mortality of 4%. The chemical fractionation of the stem and bark extract of F. petiolaris yielded five fractions of FpR1-5, which were each evaluated at 250, 500, 750, and 1,000 ppm. FpR2 had the strongest aphicidal effect, with 89% mortality at 72 hours at 1,000 ppm. The pure xanthotoxin compound extracted from this fraction was even more effective, with 91% aphid mortality after 72 h at 100 ppm. The lethal concentration (LC₅₀) of xanthotoxin was 58.7 ppm (72h). Our results indicate that the extract of F. petiolaris showed toxic activity against this aphid, and its xanthotoxin compound showed strong aphicidal activity at low concentrations.

Mosquitocidal effect of monoterpene ester and its acetyl derivative from Blumea mollis (D. Don) Merr against Culex quinquefasciatus (Diptera: Culicidae) and their insilico studies

The present study was conducted to assess the mosquitocidal efficiency of compound isolated from Blumea mollis (D. Don) Merr against Culex quinquefasciatus. Eggs and larvae of Cx. uinquefasciatus were exposed to different concentrations 0.5, 1.0, 1.5 and 2.0 ppm of compounds prepared using DMSO. Compound 1 was identified as (4R, 5S)-4-hydroxy-7-tigloyloxy carvotanacetone, from which new derivative was synthesized and confirmed as (4R, 5S)-4-acetoxy-7-tigloyloxy carvotanacetone. Both the compounds presented larvicidal and ovicidal activities. Compounds 1 and 2 at 2-ppm concentration showed 64% and 78% larval mortality in 24 h, respectively. The LC₅₀and LC₉₀values of compounds 1 and 2 on Cx. quinquefasciatus larvae were 1.73, 1.27 and 4.59, 3.33 ppm, respectively. The eluted compound 1 and synthesized compound 2 presented 68% and 77% of ovicidal activity, respectively, against eggs of Cx. quinquefasciatus at 120 h post-treatment. Histopathological studies of the compound-treated larvae revealed serious damage on the larval midgut cells. Furthermore, compounds 1 and 2 was tested for toxicity study and the results showed both the compounds were found to be harmless to non-target organism Poecilia reticulata. Computational analysis of compound 2 showed strong binding interaction with the AChE1 of Cx. quinquefasciatus. These results clearly suggest that compounds from Blumea mollis could act as good mosquitocidal agents against Cx.quinquefasciatus and compound 2 was first time reported.

An Overview of Phytochemical and Biological Activities: Ficus deltoidea Jack and Other Ficus spp

Ficus deltoidea Jack (Moraceae) is a well-known medicinal plant used in customary medication among the Malay people to reduce and mend sicknesses such as ulcers, psoriasis, cytotoxicity, cardioprotective, inflammation, jaundice, vitiligo, hemorrhage, diabetes, convulsion, hepatitis, dysentery injuries, wounds, and stiffness. Ficus deltoidea contains a wide variety of bioactive compounds from different phytochemical groups such as alkaloids, phenols, flavonoids, saponins, sterols, terpenes, carbohydrates, and proteins. The genus Ficus has several hundreds of species, which shows excellent therapeutic effects and a wide variety of helpful properties for human welfare. Searching information was collected by using electronic databases including Web of Science, Science Direct, Springer, SciFinder, PubMed, Scopus, Medline, Embase, and Google Scholar. This review is, therefore, an effort to give a detailed survey of the literature on its pharmacognosy, phytochemistry, phytochemical, and pharmacological properties of Ficus and its important species. This summary could be beneficial for future research aiming to exploit the therapeutic potential of Ficus and its useful medicinal species.

Larvicidal and antibacterial activity of aqueous leaf extract of Peepal (Ficus religiosa) synthesized nanoparticles

In this study, the zinc oxide nanoparticles (ZnO NPs) and titanium dioxide nanoparticles (TiO2 NPs) were synthesized using the aqueous leaf extract of Ficus religiosa (Peepal tree). The synthesized nanoparticles were tested as larvicides against the larvae of Anopheles stephensi. Further, the synthesized nanoparticles were tested as antibacterial agents against the Escherichia coli (gram negative) and Staphylococcus aureus (gram positive) bacteria. The synthesized nanoparticles were characterized with UV-visible spectroscopy, X-rays powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). The larvicidal mortality was observed after 24 h and 48 h by probit analysis. The antibacterial activity was evaluated using the well diffusion method. The synthesized nanoparticles were irregular shape and varied size. The larvae of An. stephensi were found highly susceptible against the ZnO NPs than the TiO2 NPs and aqueous leaves extract. The highest mortality was observed in synthesized ZnO NPs against first to third instars of (LC50 50, 75, and 5 ppm) and 100% mortality in fourth instars of An. stephensi. The higher zone of inhibition was occurred against the E. coli. This report of present investigation revealed that the rapid biological synthesis of ZnO NPs and TiO2 NPs using aqueous leaf extract of F. religiosa would be effective potential larvicides for mosquito control as well as antimicrobial agents with eco-friendly approach.

Effect of tiliamosine, a bis, benzylisoquinoline alkaloid isolated from Tiliacora acuminata (Lam.) Hook. f. & Thom on the immature stages of filarial mosquito Culex quinquefasciatus say (Diptera: Culicidae)

The present study was aimed to check the mosquitocidal activity of tiliamosine isolated from Tiliacora acuminata (Lam.) Hook. f. & Thom against immature stages of Culex quinquefasciatus. Eggs and larvae of Cx. quinquefasciatus were exposed to different concentrations of tiliamosine - 0.5, 1.0, 1.5 and 2.0 ppm - prepared using DMSO. The compound tiliamosine showed good larvicidal activity with LC₅₀ and LC₉₀ values of 1.13 and 2.85 ppm respectively, against third-instar larvae of Cx. quinquefasciatus at 24 h. In control, the larvae exhibited normal movement. Tiliamosine exhibited 91% ovicidal activity at 2.0 ppm concentration after 120 h post-treatment. Lowest concentration of tiliamosine (0.5 ppm) showed 19% egg mortality. Histopathology study of the compound-treated larvae showed serious damage on the larval midgut cells. The treated larvae showed restless movement which was different from that of the control larvae. The larvae exhibited malformation in development. The compound tiliamosine was harmless to non-target organisms P. reticulata and Dragon fly nymph at tested concentrations. The compound was highly active and inhibited AChE in a concentration-dependent manner. Computational analysis of the tiliamosine had strong interaction with AChE1 of Cx. quinquefasciatus. This report clearly suggests that the isolated compound can be used as an insecticide to control mosquito population and thus prevent the spread of vector-borne diseases.

Dual function of active constituents from bark of Ficus racemosa L in wound healing

Background

Different parts including the latex of Ficus racemosa L. has been used as a medicine for wound healing in the Ayurveda and in the indigenous system of medicine in Sri Lanka. This plant has been evaluated for its wound healing potential using animal models. The aim of this study was to obtain an insight into the wound healing process and identify the potential wound healing active substance/s present in F. racemosa L. bark using scratch wound assay (SWA) as the in-vitro assay method.

Method

Stem bark extracts of F. racemosa were evaluated using scratch wound assay (SWA) on Baby Hamster Kidney (BHK 21) and Madin-Darby Canine Kidney (MDCK) cell lines and Kirby Bauer disc diffusion assay on common bacteria and fungi for cell migration enhancing ability and antimicrobial activity respectively. Dichloromethane and hexanes extracts which showed cell migration enhancement activity on SWA were subjected to bioactivity directed fractionation using column chromatography followed by preparative thin layer chromatography to identify the compounds responsible for the cell migration enhancement activity.

Results

Dichloromethane and hexanes extracts showed cell migration enhancement activity on both cell lines, while EtOAc and MeOH extracts showed antibacterial activity against Staphylococcus and Bacillus species and antifungal activity against Saccharomyces spp. and Candida albicans. Lupeol (1) and β-sitosterol (2) were isolated as the potential wound healing active compounds which exhibited significant cell migration enhancement activity on BHK 21 and MDCK cell lines (> 80%) in par with the positive control, asiaticoside at a concentration of 25 μM. The optimum concentration of each compound required for the maximum wound healing has been determined as 30 μM and 35 μM for 1 and 2 respectively on both cell lines. It is also established that lupeol acetate (3) isolated from the hexanes extract act as a pro-drug by undergoing hydrolysis into lupeol in the vicinity of cells.

Conclusion

Different chemical constituents present in stem bark of Ficus racemosa L show enhancement of cell migration (which corresponds to the cell proliferation) as well as antimicrobial activity. This dual action of F. racemosa stem bark provides scientific support for its traditional use in wound healing.

Larvicidal activity of natural and modified triterpenoids against Aedes aegypti (Diptera: Culicidae)

BACKGROUND

Insecticide resistance to commonly used substances demands new molecules for the chemical control of the dengue vector Aedes aegypti. Because natural product sources have been an alternative to obtain larvicidal compounds, the aim of this study was to evaluate the triterpenoids betulinic (BA) and ursolic (UA) acids and their semi-synthetic derivatives against larval Ae. aegypti. BA, UA, ten derivatives modified at the C-3 position and a positive control (diflubenzuron) were evaluated. Larvicidal assays were carried out with early fourth-instar larvae, and mortality was observed between 48 and 96 h. Doses from 200 to 10 ppm were used to calculate lethal concentrations (LCs).

RESULTS

Natural compounds, i.e. UA and BA, had the lowest LCs (LC50 of 112 and 142 ppm respectively), except for the modified compound 2b (LC50 of 130 ppm). Larvicidal activity increased significantly from 48 to 96 h for all the compounds evaluated, ranging from 20 to 50% after 48 h and from 48 to 76% after 96 h. Some derivatives, e.g. 2a and 2d, had up to a three-fold larvicidal activity increase from 48 to 96 h.

CONCLUSION

BA, UA and their derivatives showed larvicidal activity against Ae. aegypti larvae, increasing significantly from 48 to 96 h. The presence of a hydroxyl group is essential for larvicidal potential in these triterpenoids. © 2016 Society of Chemical Industry.

Acetylcholine and memory-enhancing activity of Ficus racemosa bark

Background:

Alzheimer's disease (AD) is a progressive neurodegenerative disorder resulting in dementia and enhancement of acetylcholine (Ach) levels in brain using acetylcholinesterase inhibitors is one of the most important approaches for the treatment of AD.

Methods:

In this study, aqueous extract of Ficus racemosa Linn. (Moraceae) bark having anti-inflammatory, antioxidant, and anticholinesterase activity was evaluated for its ability to enhance Ach levels, and to ascertain its antidementia activity in rats. This work was carried out under the assumption that the F. racemosa extract may show combination of actions which could be beneficial in the treatment of AD, such as neuroprotection, attributed to antioxidant and anti-infl ammatory property and may elevate levels of Ach like Ficus hispida extract reported earlier.

Results:

Administration of the extract at two levels viz., 250 and 500 mg/kg signifi cantly raised (P ≤ 0.05) Ach levels in hippocampi of rats compared to control. The percentage enhancement in Ach levels was found to be 22% and 38%, respectively. Further, the extract at both dosage levels elicited signifi cant reduction (P ≤ 0.05) in transfer latency on elevated plus-maze, which was used as an exteroceptive behavioral model to evaluate memory in rats.

Conclusion:

It is inferred that it would be worthwhile to explore the potential of F. racemosa in the management of Alzheimer disease.

Mosquito larvicidal activity of methyl-p-hydroxybenzoate isolated from the leaves of Vitex trifolia Linn

The vector-borne diseases caused by mosquitoes are one of the major health problems in many countries especially in tropical and sub-tropical countries. The resistance of mosquitoes to synthetic chemicals and environmental toxicity created by the chemicals raised the demand for finding of alternate natural molecules that control mosquito. In the present study, a crystalline compound methyl-p-hydroxybenzoate was isolated from the methanol extract of Vitex trifolia leaves and it was identified by (1)H and (13)C NMR and single crystal X-ray diffractometer. The larvicidal potential of the isolated compound was evaluated against early 4th instar larvae of Culex quinquefasciatus and Aedes aegypti. The compound exhibited 100% larval mortality of both the mosquitoes at 20 ppm with LC(50) values of 5.77 and 4.74 ppm against C. quinquefasciatus and A. aegypti, respectively. The methyl-p-hydroxybenzoate, which is reported for the first time to our best of knowledge from V. trifolia can be better explored for the control of mosquito population.

Larvicidal activity of lignans from Phryma leptostachya L. against Culex pipiens pallens

The larvicidal activity of crude petroleum ether, ethyl acetate, and methanol extracts of the whole plants of Phryma leptostachya L. was assayed for its toxicity against the early fourth instar larvae of Culex pipiens pallens. The larval mortality was observed after 24 h of exposure. Among three solvent extracts from Phyrma leptostachya L., the petroleum ether extract exhibited the best larvicidal activity. The corresponding LC₅₀ values of petroleum ether, ethyl acetate, and methanol extracts were 3.23, 5.23, and 61.86 ppm against the early fourth instar larvae of Culex pipiens pallens. The petroleum ether extract was successively subjected to column chromatography and preparative high performance liquid chromatography, and yielded the three lignans, phrymarolin-I, haedoxane A, and haedoxane E, which were isolated and identified as new mosquito larvicidal compounds. Phrymarolin-I, haedoxane A, and haedoxane E showed high larvicidal activity, for which the lethal doses LC₅₀ were estimated at 1.21, 0.025, and 0.15 ppm against the early fourth instar larvae of Culex pipiens pallens, respectively. The structures were elucidated by analyses of IR, UV, MS, and NMR spectral data. This is the first report on the mosquito larvicidal activity of the three compounds, phrymarolin-I, haedoxane A, and haedoxane E from Phyrma leptostachya L.

Larvicidal activity of metabolites from the endophytic Podospora sp. against the malaria vector Anopheles gambiae

In a screening for natural products with mosquito larvicidal activities, the endophytic fungus Podospora sp. isolated from the plant Laggera alata (Asteraceae) was conspicuous. Two xanthones, sterigmatocystin (1) and secosterigmatocystin (2), and an anthraquinone derivative (3) 13-hydroxyversicolorin B were isolated after fermentation on M(2) medium. These compounds were characterised using spectroscopic and X-ray analysis and examined against third instar larvae of Anopheles gambiae. The results demonstrated that compound 1 was the most potent one with LC(50) and LC(90) values of 13.3 and 73.5 ppm, respectively. Over 95% mortality was observed at a concentration 100 ppm after 24 h. These results compared farvorably with the commercial larvicide pylarvex® that showed 100% mortality at the same concentration. Compound 3 was less potent and had an LC(50) of 294.5 ppm and over 95% mortality was achieved at a concentration of 1,000 ppm. Secosterigmatocystin (2) revealed relatively weak activity and therefore LC values were not determined.

Traditional uses, medicinal properties, and phytopharmacology of Ficus racemosa: a review

Ficus racemosa Linn. (Moraceae) is a popular medicinal plant in India, which has long been used in Ayurveda, the ancient system of Indian medicine, for various diseases/disorders including diabetes, liver disorders, diarrhea, inflammatory conditions, hemorrhoids, respiratory, and urinary diseases. F. racemosa is pharmacologically studied for various activities including antidiabetic, antipyretic, anti-inflammatory, antitussive, hepatoprotective, and antimicrobial activities. A wide range of phytochemical constituents have been identified and isolated from various parts of F. racemosa. In this review, a comprehensive account of its traditional uses, phytochemical constituents, and pharmacological effects is presented in view of the many recent findings of importance on this plant.

Efficacy of larvicidal botanical extracts against Culex quinquefasciatus Say (Diptera: Culicidae)

The present study explored the effects of crude leaf acetone, chloroform, hot water, methanol, petroleum ether (60-80 degrees C), and water extracts of Calotropis procera (Ait) R. Br., Canna indica L., Hibiscus rosa-sinensis Linn., Ipomoea carnea Jacq. spp. fistulosa Choisy, and Sarcostemma brevistigma Wight that were selected for investigating larvicidal potential against second and fourth instar larvae of the laboratory-reared mosquito species, Culex quinquefasciatus Say, in which the major lymphatic filariasis was used. All plant extracts showed moderate larvicidal effects after 24 h of exposure at 1,000 ppm; however, the highest larval mortality was found in leaf acetone, chloroform, methanol, and petroleum ether of C. indica (LC(50) = 29.62, 59.18, 40.77, and 44.38 ppm; LC(90) = 148.55, 267.87, 165.00, and 171.91 ppm) against second instar larvae (LC(50) = 121.88, 118.25, 69.76, and 56.31 ppm; LC(90) = 624.35, 573.93, 304.27, and 248.24 ppm) and against fourth instar larvae and acetone, hot water, methanol, and petroleum ether extracts of I. carnea (LC(50) = 61.17, 41.07, 41.82, and 39.32 ppm; LC(90) = 252.91, 142.67, 423.76, and 176.39 ppm) against second instar larvae (LC(50) = 145.37, 58.00, 163.81, and 41.75 ppm; LC(90) = 573.30, 181.10, 627.38, and 162.63 ppm) and against fourth instar larvae of C. quinquefasciatus, respectively. These results suggest that the acetone, methanol extracts of C. indica and hot water, petroleum ether extracts of I. carnea have the potential to be used as an ideal eco-friendly approach for the control of the major lymphatic filariasis vector, C. quinquefasciatus.

Laboratory study on larvicidal activity of indigenous plant extracts against Anopheles subpictus and Culex tritaeniorhynchus

Anopheles subpictus and Culex tritaeniorhynchus have developed resistance to various synthetic insecticides, making its control increasingly difficult. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. The leaf acetone, chloroform, ethyl acetate, hexane, and methanol extracts of Aegle marmelos (Linn.) Correa ex Roxb, Andrographis lineata Wallich ex Nees., Andrographis paniculata (Burm.f.) Wall. ex Nees., Cocculus hirsutus (L.) Diels, Eclipta prostrata L., and Tagetes erecta L. were tested against fourth-instar larvae of malaria vector, A. subpictus Grassi and Japanese encephalitis vector, C. tritaeniorhynchus Giles (Diptera: Culicidae). All plant extracts showed moderate larvicidal effects after 24 h of exposure at 1,000 ppm; however, the highest larval mortality was found in leaf ethyl acetate of A. marmelos, E. prostrata, hexane, methanol of A. paniculata and C. hirsutus against the larvae of A. subpictus (LC(50) = 167.00, 78.28, 67.24, 142.83 ppm; LC(90) = 588.31, 360.75, 371.91, and 830.01 ppm) and against the larvae of C. tritaeniorhynchus (LC(50) = 99.03, 119.89, 88.50, 105.19 ppm; LC(90) = 479.23, 564.85, 416.39, and 507.86 ppm), respectively. These results suggest that the leaf hexane extract of A. paniculata and ethyl acetate extract of E. prostrata have the potential to be used as an ideal eco-friendly approach for the control of the A. subpictus and C. tritaeniorhynchus. Therefore, this study provides first report on the mosquito larvicidal activity of plant extracts against vectors from Southern India.

Evaluation of larvicidal and nymphicidal potential of plant extracts against Anopheles subpictus Grassi, Culex tritaeniorhynchus Giles and Aphis gossypii Glover

The acetone, chloroform, ethyl acetate, hexane and methanol extracts of peel and leaf extracts of Citrus sinensis, Ocimum canum, Ocimum sanctum and Rhinacanthus nasutus were tested against fourth instar larvae of malaria vector, Anopheles subpictus Grassi, Japanese encephalitis vector, Culex tritaeniorhynchus Giles (Diptera: Culicidae) and feeding deterrence to nymphs of cotton pest, Aphis gossypii Glover (Homoptera: Aphididae). The larval and nymph mortality were observed after 24 h of exposure. All extracts showed moderate larvicidal and nymphicidal effects; however, the highest mortality was found in peel chloroform extract of C. sinensis, leaf ethyl acetate extracts of O. canum and O. sanctum and leaf chloroform extract of R. nasutus against the larvae of A. subpictus (LC(50) = 58.25, 88.15, 21.67 and 40.46 ppm; LC(90) = 298.31, 528.70, 98.34 and 267.20 ppm), peel methanol extract of C. sinensis, leaf methanol extract of O. canum, ethyl acetate extracts of O. sanctum and R. nasutus against the larvae of C. tritaeniorhynchus (LC(50) = 38.15, 72.40, 109.12 and 39.32 ppm; LC(90) = 184.67, 268.93, 646.62 and 176.39 ppm), peel hexane extract of C. sinensis, leaf methanol extracts of O. canum and R. nasutus and leaf ethyl acetate extract of O. sanctum against the nymph of A. gossypii (LC(50) = 162.89, 80.99, 73.27 and 130.19 ppm; LC(90) = 595.40, 293.33, 338.74 and 450.90 ppm), respectively. These results suggest that the peel methanol extracts of C. sinensis and O. canum, ethyl acetate leaf extract of O. sanctum and leaf chloroform and ethyl acetate extract of R. nasutus have the potential to be used as an ideal eco-friendly approach for the control of the A. subpictus, C. tritaeniorhynchus and A. gossypii.