Pest Management Science (2012) 68, 1447-1450

Irudayaraj Geetha, Kummankottil P. Paily and Arulsamy M. Manonmani (2012)
Mosquito adulticidal activity of a biosurfactant produced by Bacillus subtilis subsp. subtilis
Pest Management Science 68 (11), 1447-1450
Abstract: BACKGROUND: A biosurfactant, surfactin, produced by a strain of Bacillus subtilis subsp. subtilis (VCRC B471), was effective in killing mosquito larval and pupal stages. As it was lethal to the non-feeding pupal stage, it was presumed that it could kill the adult mosquitoes also. In this study, the adulticidal effect of the biosurfactant was assessed in the laboratory against a malaria vector, Anopheles stephensi.
RESULTS: The biosurfactant surfactin, separated from the culture supernatant of the production strain, showed mosquito adulticidal activity when tested as ultralow-volume (ULV) spray in a Peet-Grady chamber. Knockdown activity and mortality were found to increase with increasing surfactin dosage. Knockdown dosage (KD) and lethal dosage (LD) were calculated by statistical analysis. The KD₅₀ and KD₉₀ dosages were 10.73 and 26.39 mg m⁻³ respectively. The LD₅₀ and LD₉₀ dosages were 16.13 and 39.21 mg m⁻³. The average droplet size of B. subtilis surfactin was 17.5 ± 1.07 µm.
CONCLUSION: The present study indicates that the biosurfactant surfactin, produced by B. subtilis subsp. subtilis (VCRC B471), is a potential bioadulticide for ULV spray against malaria-transmitting Anopheles stephensi mosquitoes. This is the first report of a mosquito adulticide from a microbial source.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Irudayaraj Geetha, Kummankottil P. Paily

Research topic(s) for pests/diseases/weeds:
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Anopheles stephensi