Effect of aqueous extract of lemon (Citrus limon) on Anopheles gambiae sensu lato (Diptera: Culicidae) larvae tolerance in malaria vector control in Dogbo district in south-western Republic of Benin, West Africa

The use of chemical insecticides causes important damages to environment and human health and there is a need to search for alternative solutions. This study aims to investigate on the effect of aqueous extract of lemon in Anopheles gambiae s.l. larvae tolerance in couffo department in south-western Republic of Benin, West Africa. Larvae of Anopheles gambiae s.l mosquitoes were collected from breeding sites using the dipping method in July 2020 during the rainy season in Dogbo district. A batch of 15 larvae of fourth instar were exposed to a mixture of aqueous extract of lemon with distilled water saturated with oxygen containing in each of five glass jars or test cups of same dimensions contained each 48 ml distilled water saturated with oxygen plus 2 ml of aqueous extract of lemon (Citrus limon) and one control jar containing no trace of aqueous extract of lemon. Larval mortality was recorded after 24hours, 48hours and 72hours exposure. The results show that the use of aqueous extract of lemon causes full-grown Anopheles larvae to die by suffocation. After the application of this mixture, the larvae of four instars cannot breathe. The use of aqueous extract of lemon is effective method for disturbing the siphonal respiration of mosquito larvae. Aqueous extract of lemon is effective method for mosquito larvae control.

Download Full-text

Effect of coconut oil on Anopheles gambiae sensu lato (Diptera: Culicidae) larvae tolerance in malaria vector control in Dogbo district in south-western Benin, West Africa

GSC Advanced Research and Reviews ◽

10.30574/gscarr.2021.9.2.0221 ◽

2021 ◽

Vol 9 (2) ◽

pp. 001-007

Author(s):

Nazaire Aïzoun ◽

Arlette Adjatin ◽

Géorcelin Alowanou

Keyword(s):

West Africa ◽

Vector Control ◽

Anopheles Gambiae ◽

Malaria Vector ◽

Larval Mortality ◽

Coconut Oil ◽

Malaria Vector Control ◽

Mosquito Larvae ◽

Distilled Water ◽

Water Saturated

The use of chemical insecticides causes important damages to environment and human health and there is a need to search for alternative solutions. This study aims to investigate on the effect of coconut oil on Anopheles gambiae sensu lato larvae tolerance in malaria vector control in Dogbo district in south-western Benin, West Africa. Larvae of Anopheles gambiae s.l. mosquitoes were collected from breeding sites using the dipping method in May 2020 during the rainy season in Dogbo district. A batch of 25 larvae of fourth instar were exposed to a mixture of coconut oil with distilled water saturated with oxygen containing in each of five glass jars or test cups of same dimensions contained each 48 ml distilled water saturated with oxygen plus 2 ml of coconut oil and one control jar containing no trace of coconut oil. Larval mortality was recorded after 24 hours, 48 hours and 72hours exposure. The results show that the use of coconut oil causes full-grown Anopheles larvae to die by suffocation. After the application of this mixture, the larvae of four instars cannot breathe. The use of coconut oil is effective method for disturbing the siphonal respiration of mosquito larvae. Coconut oil is effective method for mosquito larvae control.

Download Full-text

Chemical composition and insecticidal activity of Aeollanthus pubescens Benth leaf essential oil on the malaria vector Anopheles gambiae (Diptera: Culicidae)

10.1101/2020.11.25.397588 ◽

2020 ◽

Author(s):

Roméo Barnabé Bohounton ◽

Luc Salako Djogbénou ◽

Oswald Yédjinnavênan Djihinto ◽

Oronce Sedjro-Ludolphe Dedome ◽

Pierre Marie Sovegnon ◽

...

Keyword(s):

Chemical Composition ◽

Essential Oil ◽

Anopheles Gambiae ◽

Malaria Vector ◽

Larval Mortality ◽

Alternative Approach ◽

Leaf Essential Oil ◽

Republic Of Benin ◽

The Republic ◽

Major Malaria Vector

AbstractThe use of synthetic insecticides is responsible for many cases of resistance in insects. Therefore, the use of natural molecules of ecological interest with insecticidal properties turns out to be an alternative approach to the use of synthetic insecticides. This study aims at investigating the larvicidal, adulticidal activity and the composition of the essential oil of Aeollanthus pubescens Benth on the major malaria vector Anopheles gambiae.The leaves of Aeollanthus pubescens were collected in the South of the Republic of Benin. Three reference strains of Anopheles gambiae s.s. such as Kisumu, Kiskdr and Acerkis were used. The chemical composition of the essential oil was analysed by gas chromatography coupled to mass spectrometry. Larvae were exposed to the essential oil extract for 24 h. Adult mosquitoes were exposed to the fragment nets coated with the essential oil for 3 min. Larval mortality and adult survivorship were monitored.Fourteen components were identified representing 98.31% of the total of oil. The major components were carvacrol (51.06 %), thymyle acetate (14.01 %) and γ-terpinene (10.60 %). The essential oil has remarkable larvicidal properties with LC50 of 29.26, 22.65, and 28.37 ppm respectively on Kisumu, Acerkis and Kiskdr strains. With the fragment net treated at 165 µg/cm2, the KDT50 of both Acerkis (1.71 s, p < 0.001) and Kiskdr (2.67 s, p < 0.001) individuals were significantly lower than that of Kisumu (3.77 s). The lifespan of the three mosquito strains decreased respectively to one day for Kisumu (p < 0.001), two days for Acerkis (p < 0.001) and three days for Kiskdr (p < 0.001) compared to their control.Our findings show that the Aeollanthus pubescens essential oil is an efficient larvicide and adulticide against malaria vector Anopheles gambiae. This bioinsecticidal activity is a promising discovery for the control of the resistant malaria-transmitting vectors.

Download Full-text

Bioefficacy of local Lantana camara (Verberneae) plant extracts against the 3rd instar larva and adult stages of Anopheles gambiae senso lato (Giles).

Journal of Medical Research and Health Sciences ◽

10.15520/jmrhs.v3i12.214 ◽

2020 ◽

Vol 3 (12) ◽

pp. 1120-1129

Author(s):

Wenceslas Yana ◽

Enda Corinna Andu ◽

Katamssadan Haman Tofel ◽

Abe Henri

Keyword(s):

Anopheles Gambiae ◽

Aqueous Extract ◽

Exposure Time ◽

Larval Mortality ◽

Acetone Extract ◽

Lantana Camara ◽

Hexane Extract ◽

Lethal Concentration ◽

Malaria Vectors ◽

Malaria Vector Control

Resistance of malaria vectors to synthetic chemicals with high operational cost and environmental pollution has been a great challenge to scientists. Alternative approaches such as the use of natural plant products which are environmentally friendly are put in place to control malaria vectors. This study was focused on testing the effectiveness of three solvent extracts of Lantana camara on the 3rd instar larvae and adults of Anopheles gambiae s. l. These extracts were obtained by maceration. Bioassays test were carried out by WHO’s method for determination of larvicidal and adulticidal efficacy. The results show that, larval mortality increased significantly with the concentration and exposure time. Lethal concentrations 50 (LC50) and 95 (LC95) after 24 hours of larvae exposure time are respectively 0.31 g/mL and 1.53 g/mL while within 48 h they are 0.27 g/mL and 0.79 g/mL for hexane extract; 1.45 g/mL and 2.0 g/mL (24 h exposure), 0.84 g/mL and 1.55 g/mL (48 h exposure) for acetone extract; 1.96 g/mL and no lethal concentration causing 95% mortality was determined; 0.40 g/mL and 2.20 g/mL (48 h) for aqueous extract. The efficacy of hexane and aqueous extract on the adult knock down and mortality were not significant even with the increasing extract concentrations and exposure time whereas with acetone extract, the adult LC50 after 24 h was 2.4 g/mL but with 95% mortality lethal concentration was not determined. According to the results, hexane extract showed high larvicidal efficacy of An. gambiae and acetone extract showed significant adult mortality. Those two extracts of L. camara can be used to fight against An. gambiae as alternative malaria vector control to replace conventional insecticides.

Download Full-text