Efficacy of entomopathogenic nematode strains against engorged Boophilus annulatus females (Acari: Ixodidae) under simulated field conditions.

The biocidal efficacy of entompathogenic nematodes against engorged females of Boophilus annulatus (Say) was evaluated in soil-filled buckets in a greenhouse, where conditions resemble nature. The 9 tested nematode strains differed markedly in their effect upon tick mortality. The Mexican strain of Steinernema carpocapsae was most efficient, inducing 100% tick mortality at a concentration of 50 nematodes per square centimeter. An increase in the concentration of the S. carpocapsae DT strain to > 200 IJ/cm2 failed to kill more ticks. It appears that entomopathogenic nematodes show promise as tick control agents.