Efficacy of Lagenidium giganteum (Couch) metabolites for control Anopheles stephensi (Liston) a malaria vector

Background

Lagenidium giganteum (Couch) a water mold of class Oomy-cetes, is a facultative parasite of mosquito. The metabolites of L. giganteum were tested for control of Anopheles stephensi. This fungus was grown in Peptone yeast extract glucose (PYG) broth in the laboratory at 25±2°C, and relative humidity was maintained at 75±5% for 15±2 days. The filtration process of metabolites was done using Whatman-1 filter paper and then with Flash chromatography. These purified metabolites were spray at five (3,4,5,6,7 ml/m²) different statistically significant concentrations. The efficacy after whatman-1 the LC₅₀-5ml/m², LC₉₀-7.07 ml/m² and LC₉₉-10 ml/m2 values were found effective after exposure of 1 5h. LT₅₀-10.23 h and LT₉₀-16.59 h were recorded. Similarly, efficacy after Flash chromatography the LC₅₀-4 ml/m², LC₉₀-6 ml/m² and LC₉₉-6.76ml/m2 values were found effective after exposure of 15h. The LT₅₀-6.16h and LT₉₀-12.02h were observed. This study reveals the metabolites of L. giganteum could be used for control of An. stephensi a malaria vector. Figures 1, 2, 3

Figure 1

The culture of L. giganteum in Peptone yeast extract glucose (PYG) broth in the laboratory.

Figure 2

Probit regression line depicting relationship between probit of kill and log dose concentrations of metabolites of L. giganteum after 15 h exposure for An. stephensi.

Figure 3

Probit regression line depicting relationship between probit of kill and log time of L. giganteum for An. stephensi.

Conclusion

Present study shows a high potential utility of fungal metabolites for complementing existing adult mosquito control measures. This approach demonstrates that the fugal metabolites have potential as a new strategy for vector control. It could be successful tool for controlling malaria vector in tropical countries with more community trials. Mosquitoes that are resistant to insecticides remain susceptible to fungal infection (Knols et al. 2010). Recently metabolites of F. oxysporum show significant pathogenicity against the larvae of An. stephensi in laboratory (Prakash et al. 2010). Regardless, the use of fungi L. giganteum to control population of An. stephensi mosquitoes clearly offers significant promise as a novel biologically based strategy to be integrated with other control measures to reduce global rate of malaria transmission. Also Scholte et al. (2005) have used fungal spores as adulticidal to control vector population in African villages, so fungal metabolites can be used as novel liquid adulticide.