Wichai Kong-ngamsuk*
Prakong Phan-Urai*
Usavadee Thavara*
Sompop Kotwong*

Affiliations :
      *Entomology group, National Institute of Health, Department of Medical Sciences, Ministry of Public Health, Nonthaburi

Source:
      Ministry of Public Health Journal. 1998; 17(4): 115-124

Language:
      Thai with English abstract

Abstract:
      Bacillus sphaericus   H.5, Kanchanaburi strain is the micro-organism which had been proved that it has effectivness for Culex quinquefasciatus   mosquito larva control. This study, fermentation technique had been used for production development with soy bean, ground meat and powder of yeast as substrate for this micro-organism. With the period of 120 hrs, the yield around 1.5 gms/litre was oftained. After the yield was tested by standard method, it was found that the toxicity to larva was 500 ITU/mg Cx. quin.   The implementation of whole beer from this product in natural breeding places at the concentration of 1 litre per 6 square meters, could reduce the density of Culex quinquefasciatus   mosquito larva at the 90 percentage level for 2 weeks. Not only the Bacillus sphaericus   H.5 did control the mosquito larva but it could also improve the quality of water of the breeding place.