Efficacy of botanical extracts from Callitris glaucophylla, against Aedes aegypti and Culex annulirostris mosquitoes (2025)

Effects of sub lethal concentrations of synthetic insecticides and Callitris glauscophylla extracts on the development of Aedes aegypti

Journal of vector …, 2005

Synthetic and botanical insecticides can have a profound effect on the developmental period, growth, adult emergence, fecundity, fertility, and egg hatch, resulting in effective control at sub-lethal concentrations. This paper investigated sub-lethal concentrations of fenitrothion, lambda-cyhalothrin, and Callitris glaucophylla Joy Thomps. & L.P. Johnson (Cupressaceae) extract to characterize their effects on the development of Aedes aegypti L. (Diptera: Culicidae) mosquito larvae. The LC 25 , LC 50 , and LC 75 (four replicates) were used for each synthetic insecticide and the LC 25 and LC 75 (four replicates) were used for C. glaucophylla. Observations of larval mortality, duration of larval stage, pupal mortality, duration of pupal stage, adult emergence, sex ratio, and malformations were recorded over 14 days. A dose-response effect was observed for all insecticides. Although C. glaucophylla extract doses were higher than synthetic insecticide doses, the LC 75 treatment outperformed synthetics by completely prohibiting adult emergence. Consequently, this botanical is recommended for field application either in combination with synthetic or natural insecticides or alone. Journal of Vector Ecology 30 (2): 295-298. 2005.

The Effect of Some Plant Extracts on Mosquito Aedes aegypti (L.)

Biosciences Biotechnology Research Asia, 2014

Mosquito larvicidal, ovicidal, and repellent properties of botanical extracts against Anopheles stephensi , Aedes aegypti , and Culex quinquefasciatus (Diptera: Culicidae

Parasitology Research

Mosquito-borne diseases have an economic impact, including loss in commercial and labor outputs, particularly in countries with tropical and subtropical climates; however, no part of the world is free from vector-borne diseases. In mosquito control programs, botanical origin may have the potential to be used successfully as eggs, larvae, and adult. The larvicidal, ovicidal, and repellent activities of crude benzene and ethyl acetate extracts of leaf of Ervatamia coronaria and Caesalpinia pulcherrima were assayed for their toxicity against three important vector mosquitoes, viz., Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus (Diptera: Culicidae). The larval mortality was observed after 24 h of exposure. All extracts showed moderate larvicidal effects; however, the highest larval mortality was found in benzene extract of E. coronaria against the larvae of Anopheles Stephensi, Aedes aegypti, and Culex quinquefasciatus with the LC50 and LC90 values were 79.08, 89.59, and 96.15 ppm and 150.47, 166.04, and 174.10 ppm, respectively. Mean percent hatchability of the ovicidal activity was observed 48 h posttreatment. The percent hatchability was inversely proportional to the concentration of extract and directly proportional to the eggs. The leaf extract of E. coronaria was found to be most effective than Caesalpinia pulcherrima against eggs/egg rafts of three vector mosquitoes. For E. coronaria, the benzene extract exerted 300, 250, and 200 ppm against Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus, respectively. The results of the repellent activity of benzene and ethyl acetate extract of E. coronaria and Caesalpinia pulcherrima plants at three different concentrations of 1.0, 2.5, and 5.0 mg/cm2 were applied on skin of fore arm in man and exposed against adult female mosquitoes. In this observation, these two plant crude extracts gave protection against mosquito bites without any allergic reaction to the test person, and also, the repellent activity is dependent on the strength of the plant extracts. These results suggest that the leaf solvent plant extracts have the potential to be used as an ideal ecofriendly approach for the control of mosquitoes. This is the first report on the mosquito larvicidal, ovicidal, and repellent activities of the reported E. coronaria and Caesalpinia pulcherrima plants.

Environmental Science and Pollution Research Larvicidal activity of selected plant extracts and their combination against the mosquito vectors Culex quinquefasciatus and Aedes aegypti

Environmental Science and Pollution Research

In order to develop an environment-friendly botanical mosquito larvicide alternative to the chemical larvicides, extracts were made from the leaves of Hyptis suaveolens, Lantana camara, Nerium oleander, and Tecoma stans with three organic solvents such as methanol (ME), chloroform (CH), and petroleum ether (PE) using a Soxhlet extractor. The plant extracts were screened for larvicidal activity individually and in combination against the larvae of Aedes aegypti and Culex quinquefasciatus as per WHO protocol. Among the extracts, the maximum larvicidal activity was shown by the PE extract of L. camara (LC50 10.63 mg/ L) followed by the PE extract of T. stans (LC50 19.26 mg/L), ME extract of N. oleander (LC50 35.82 mg/L), and PE extract of H. suaveolens (LC50 38.39 mg/L) against Cx. quinquefasciatus. In the case of Ae. aegypti, the PE extract of T. stans showed maximum activity with LC50 value of 55.41 mg/L followed by H. suaveolens (LC50 64.49 mg/L), PE extract of L. camara (LC50 74.93 mg/L), and ME extract of N. oleander (LC50 84.09). A blend of these four extracts resulted in a combination with corresponding LC50 values of 4.32 and 7.19 mg/L against Cx. quinquefasciatus and Ae. aegypti. The predator safety factors were 12.55 and 20.88 for Gambusia affinis with respect to Aedes and Culex larvae for the extract combination. Chemical constituents in extracts were also identified by FT-IR and GC-MS data. The present investigations suggest the possible use of this blend of botanical extracts as an ideal ecofriendly, larvicide against Ae. aegypti and Cx. quinquefasciatus larvae.

Study of chemical composition and larvicidal efficacy of secondary metabolites from aromatic phytoextracts against dengue vector: Aedes aegypti (Linn) (Diptera: Culicidae

Mosquitoes have not only threatened human health but also adversely affect human and wild life as they act as vector for many deadly diseases. Among vector mosquito Aedes aegypti plays a key vector role to transmit viral diseases viz. Dengue, Zika, Yellow Fever and Chikunguniya. The present scenario for vector control strategies exposes the fact of rise in resistance index of mosquitoes against various available synthetic insecticides and also nonresponsive to bacterial larvicides. To overcome these circumstances, more emphasis should be given to bio-control strategies using secondary metabolites from plant extracts; since, they are enriched in bioactive components with larvicidal activity. Present study analyzed chemical composition and larvicidal efficacy of flowers of Gliricidia sepium and seeds of Annona squamosa in methanolic and hexane extracts. The bioassay for larvicidal activity was carried out using II, III, IV instar larvae of Aedes aegypti. It was observed that early instar stages showed more sensitivity to EOs as compared to later immature developing stages. The lowest LC50 values shown by second, third, fourth instar larvae in methanol extract of Gliricidia sepium as 38.01ppm, 45.65 ppm, 60.25 ppm respectively whereas highest LC50 values against II, III, IV instar larvae of Aedes aegypti were 77.62 ppm, 95.40 ppm, 128.82 ppm respectively in hexane extract of Annona squamosa. EOs of Gliricidia sepium can be used as an effective biolarvicide to control mosquitoes as environment friendly solution.

Efficacy of Some Selected Indigenous Plant Extracts against Two Urban Mosquitoes Culex quinquefasciatus Say and Aedes aegypti L.

Elixir Appl. Zoology 118 (2018) 50857-50866, 2018

Efficacies of the chloroform and aqueous extracts of the leaf, stem and root of three indigenous plants viz. Calotropis procera, Polygonum hydropiper and Thevetia neriifolia against the larval mortality and reproductive potential of two urban mosquitoes Culex quinquefasciatus Say and Aedes aegypti L. are reported here. Results show that the chloroform extracts of C. procera leaf (LC50 = 167.48 ppm), P. hydropiper stem (LC50 = 341.79 ppm) and T. neriifolia leaf (LC50 = 209.45 ppm) had excellent larvicidal effect on Cx. quinquefasciatus. The aqueous extracts of C. procera stem (LC50 = 207.18 ppm), P. hydropiper stem (LC50 = 634.92 ppm) and T. neriifolia leaf (LC50 = 453.34 ppm), however, had relatively milder larvicidal effect on the mosquitoes under study. Both the extracts significantly reduced percentage of egg-hatch and adult emergence per raft, lengthened immature duration and increased immature mortality in all the treatment groups. The chloroform extracts had a significantly negative effect on the number of eggs per raft, but both chloroform and aqueous extracts failed to induce any appreciable effect on the female ratio. Compared to the aqueous extracts, chloroform extracts are much more efficient against Cx. quinquefasciatus productivity. Results on Ae. aegypti indicated that the leaf extracts of C. procera (LC50 =696.14 ppm), the stem extract of P. hydropiper (LC50 =1164.36 ppm), and the leaf extract of T. neriifolia (LC50 =872.91 ppm) had significant larvicidal effects compared to the respective controls. In general, the extracts significantly reduced egg-laying, decreased egg-hatch, lengthened immature duration, and increased immature mortality culminating in reduced adult emergence. A comparison of the larvicidal efficacy of the extracts against the two mosquito species reveals that Cx. quinquefasciatus is more sensitive to the plant extracts than Ae. aegypti. However, further research is solicited to evaluate the impact, persistence and effectiveness of these extracts against the vector mosquitoes under indoor and field conditions.

Synergistic efficacy of botanical blends with and without synthetic insecticides against Aedes aegypti and Culex annulirostris mosquitoes

Journal of vector …, 2005

Increasing insecticide resistance requires strategies to prolong the use of highly effective vector control compounds. The use of combinations of insecticides with other insecticides and phytochemicals is one such strategy that is suitable for mosquito control. In bioassays with Aedes aegypti and Culex annulirostris mosquitoes, binary mixtures of phytochemicals with or without synthetic insecticides produced promising results when each was applied at a LC 25 dose. All mixtures resulted in 100% mortality against Cx. annulirostris larvae within 24 h rather than the expected mortality of 50%. All mixtures acted synergistically against Ae. aegypti larvae within the first 24 h except for one mixture that showed an additive effect. We conclude that mixtures are more effective than insecticides or phytochemicals alone and that they enable a reduced dose to be applied for vector control potentially leading to improved resistance management and reduced costs. Journal of Vector Ecology 30 (2): 284-288. 2005.

Ovicidal and repellent activities of botanical extracts against Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi (Diptera: Culicidae

Adulticidal and repellent properties of indigenous plant extracts against Culex quinquefasciatus and Aedes aegypti (Diptera: Culicidae)

Parasitology Research, 2011

Several diseases are associated to the mosquitohuman interaction. Mosquitoes are the carriers of severe and well-known illnesses such as malaria, arboviral encephalitis, dengue fever, chikunguniya fever, West Nile virus, and yellow fever. These diseases produce significant morbidity and mortality in humans and livestock around the world. The adulticidal and repellent activities of crude hexane, ethyl acetate, benzene, chloroform, and methanol extracts of leaf of Eclipta alba and Andrographis paniculata were assayed for their toxicity against two important vector mosquitoes, viz., Culex quinquefasciatus and Aedes aegypti (Diptera: Culicidae). The adult mortality was observed after 24 h of exposure. All extracts showed moderate adulticide effects; however, the highest adult mortality was found in methanol extract of A. paniculata against the adults of C. quinquefasciatus and A. aegypti with the LC 50 and LC 90 values were 149.81, 172.37 ppm and 288.12, 321.01 ppm, respectively. The results of the repellent activity of hexane, ethyl acetate, benzene, chloroform, and methanol extract of E. alba and A. paniculata plants at three different concentrations of 1.0, 2.5, and 5.0 mg/cm 2 were applied on skin of forearm in man and exposed against adult female mosquitoes. In this observation, these two plant crude extracts gave protection against mosquito bites without any allergic reaction to the test person, and also, the repellent activity is dependent on the strength of the plant extracts. These results suggest that the leaf solvent plant extracts have the potential to be used as an ideal ecofriendly approach for the control of mosquitoes. This is the first report on the mosquito adulticidal and repellent activities of the reported E. alba and A. paniculata plants.

Larvicidal activity of selected plant extracts and their combination against the mosquito vectors Culex quinquefasciatus and Aedes aegypti

Environmental Science and Pollution Research, 2018

In order to develop an environment-friendly botanical mosquito larvicide alternative to the chemical larvicides, extracts were made from the leaves of Hyptis suaveolens, Lantana camara, Nerium oleander, and Tecoma stans with three organic solvents such as methanol (ME), chloroform (CH), and petroleum ether (PE) using a Soxhlet extractor. The plant extracts were screened for larvicidal activity individually and in combination against the larvae of Aedes aegypti and Culex quinquefasciatus as per WHO protocol. Among the extracts, the maximum larvicidal activity was shown by the PE extract of L. camara (LC 50 10.63 mg/ L) followed by the PE extract of T. stans (LC 50 19.26 mg/L), ME extract of N. oleander (LC 50 35.82 mg/L), and PE extract of H. suaveolens (LC 50 38.39 mg/L) against Cx. quinquefasciatus. In the case of Ae. aegypti, the PE extract of T. stans showed maximum activity with LC 50 value of 55.41 mg/L followed by H. suaveolens (LC 50 64.49 mg/L), PE extract of L. camara (LC 50 74.93 mg/L), and ME extract of N. oleander (LC 50 84.09). A blend of these four extracts resulted in a combination with corresponding LC 50 values of 4.32 and 7.19 mg/L against Cx. quinquefasciatus and Ae. aegypti. The predator safety factors were 12.55 and 20.88 for Gambusia affinis with respect to Aedes and Culex larvae for the extract combination. Chemical constituents in extracts were also identified by FT-IR and GC-MS data. The present investigations suggest the possible use of this blend of botanical extracts as an ideal ecofriendly, larvicide against Ae. aegypti and Cx. quinquefasciatus larvae.