[Duration of the larvicidal effect of spore crystalline mass of bacteria Bacillus thuringiensis spp. israelensis and Bacillus sphaericus in the laboratory setting].
The duration of action of sporocrystalline mass of Bacillus thuringiensis spp. Israelensis (Bti) and Bacillus sphaericus (Bsph) against three-age larvae of An. stephensi mosquitoes was studied in the laboratory setting. The duration of action depends on its initial concentration. The optimal concentration should be at least 10(5) spores/ml for An. stephensi larvae. Decreasing the concentration reduces the duration of larvicidal action. Increasing the number of the larvae placed also diminishes the duration of action shown by Bti. This has no significant influence on the duration of action by Bsph. The presence of dead larvae in the test vessel increases the duration of action by Bti only by 4 times whereas Bsph acts rather long. The follow-ups lasted 60 weeks with full death of the larvae placed again. A significant water resistance of Bti sporocrystalline mixture was found. The mixture retained its larvicidal activity 6 months following its presence in the dechlorinated water without larval placement. Bsph was less resistant and its complete inactivity was noted under the same conditions just following 2 months.
Ganushkina
L A
LA
Lebedeva
N N
NN
Azizbekian
R R
RR
Sergiev
V P
VP
D000818:Animals; D000852:Anopheles / Q000254:growth & development*; D001407:Bacillus / Q000254:growth & development / Q000502:physiology*; D001413:Bacillus thuringiensis / Q000254:growth & development; D003470:Culture Media; D009032:Mosquito Control; D013171:Spores, Bacterial / Q000254:growth & development / Q000502:physiology; D013997:Time Factors
D003470:Culture Media
Prodolzhitel'nost' larvitsidnogo deĭstviia sporokristallicheskoĭ massy bakteriĭ Bacillus thuringiensis spp. israelensis i Bacillus sphaericus v laboratornykh usloviiakh.