Chenopodium ambrosioides L. (Amaranthaceae) (wormseed) is a strongly aromatic plant employed popularly for its antiparasitic properties. This study evaluated the in vitro efficacy on laying and hatchability of eggs of Rhipicephalus (Boophilus) microplus (Canestrini, 1888) (Acari: Ixodidae) of hydroethanolic extracts from C. ambrosioides, using the adult immersion test. The treatments consisted of hydroethanolic extracts made with 5%, 10% and 25% of C. ambrosioides (weight/volume), distilled water and vehicle solution (consisting of propylene glycol at 5%, ethanol at 25% and distilled water). Ten ticks were distributed evenly for each group and immersed for 5 minutes in each of the tested extracts. The extracts containing 5%, 10% and 25% of C. ambrosioides showed average efficacies 13.27%, 22.56% and 31.87% respectively. These results indicate that extracts of C. ambrosioides, at the concentrations used, do not present potential for the control of the R. (B.) microplus strains researched.
Wormseed; acaricide; phytotherapy; cattle tick control