Evaluation of Bacillus thuringiensis pathogenicity for a strain of the tick, Rhipicephalus microplus, resistant to chemical pesticides.
The pathogenicity of four native strains of Bacillus thuringiensis against Rhipicephalus (Boophilus) microplus (Canestrine) (Acari: Ixodidae) was evaluated. A R. microplus strain that is resistant to organophosphates, pyrethroids, and amidines, was used in this study. Adult R. microplus females were bioassayed using the immersion test of Drummond against 60 B. thuringiensis strains. Four strains, GP123, GP138, GP130, and GP140, were found to be toxic. For the immersion test, the total protein concentration for each bacterial strain was 1.25 mg/ml. Mortality, oviposition, and egg hatch were recorded. All of the bacterial strains had significant effects compared to the controls, but no significant differences were seen between the 4 strains. It is evident that these B. thuringiensis strains have a considerable detrimental effect on the R. microplus strain that is resistant to pesticides.
Centro Nacional de Investigaciones en Parasitología Veterinaria INIFAP Km 11.5 Carretera Federal Cuernavaca-Cuautla, Col Progreso, Jiutepec, Morelos, México, CP 62550. fernadez.manuel@inifap.gob.mx
Manuel
M
Fernández-Ruvalcaba
Guadalupe
G
Peña-Chora
Armando
A
Romo-Martínez
Víctor
V
Hernández-Velázquez
Alejandra Bravo
AB
de la Parra
Diego Pérez
DP
De La Rosa
D000704:Analysis of Variance; D000818:Animals; D001413:Bacillus thuringiensis / Q000472:pathogenicity*; D005260:Female; D005298:Fertility / Q000502:physiology; D007305:Insecticide Resistance; D008800:Mexico; D009026:Mortality; D010058:Oviposition / Q000502:physiology; D010572:Pest Control, Biological / Q000379:methods*; D048494:Rhipicephalus / Q000382:microbiology*; D013045:Species Specificity