Effects of culture medium and formulation on the larvicidal activity of the mosquito pathogen Lagenidium giganteum (Oomycetes: Lagenidiales) against Aedes aegypti.
In this work, we examined the production of infective zoospores of Lagenidium giganteum in four culture media, and the larvicidal activity of the cultures was determined against Aedes aegypti larvae, as well as the effect of polymer encapsulation. Medium containing sunflower seed extract showed the greatest production of zoospores, 5.92×10(6) zoospores/ml after six days of fermentation at 25±2°C and 150rpm shaking. This culture tested against A. aegypti 1st stage larvae caused different mortality rates at 24, 48 and 72h posttreatment. The LC(50) obtained was 43.9, 41.1 and 42.9μl of total culture/ml, at 24, 48 and 72h posttreatment respectively, while the culture grown in medium with soybean meal showed 3-5 times higher LC(50) values. Finally, the total culture including mycelium, zoospores and presporangia formulated with 2.5% pectin showed significantly higher mortality rates, around 100% more than the unformulated culture, whose values were from 40 to 1% at 3, 6, 9, and 12d posttreatment in the bioassays carried out in the laboratory to determine residual activity.
Instituto de Biotecnología, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León., Av. Pedro de Alba y Manuel L., Barragán s/n Ciudad Universitaria, C. P. 66450, A. P. 414 y 2790, San Nicolás de los Garza, Nuevo León, Mexico. mgpemald@hotmail.com
María Guadalupe
MG
Maldonado-Blanco
Erika Yazmín
EY
Leal-López
Ozmel Alejandro
OA
Ochoa-Salazar
Myriam
M
Elías-Santos
Luis Jesús
LJ
Galán-Wong
Humberto
H
Quiroz-Martínez
D000330:Aedes; D000704:Analysis of Variance; D000818:Animals; D003470:Culture Media / Q000494:pharmacology*; D006368:Helianthus; D044726:Lagenidium / Q000187:drug effects* / Q000254:growth & development*; D007814:Larva; D007928:Lethal Dose 50; D009032:Mosquito Control; D009868:Oomycetes / Q000187:drug effects; D010572:Pest Control, Biological; D012639:Seeds; D013025:Glycine max
D003470:Culture Media