Objective: to determine the effect of coumaphos on Rhipicephalus microplus and entomopathogenic nematodes in bovine production units.Design/methodology/approach: Two experiments were carried out: First) tick samples were collected and evaluated, using the Adult Immersion Test (10 ticks per humid chamber), the treatments were applied: 1: Control; 2: Coumaphos 0.1%; 3: Coumaphos 0.2%; 4: Coumaphos 0.4%. An ANOVA was carried out with a completely randomized design (mortality dependent variable and treatment independent variable with four levels) and a multiple comparison of means (Tukey’s test). Second experiment) 10 samples of livestock soil where coumaphos is used, which correspond to the Mariano Matamoros ejido, Tamaulipas, and 10 non-livestock soil from the Las Huastecas Experimental Field, were analyzed to determine the presence of entomopathogenic nematodes (EPN). a cross-frequency table between the sampled soils and the Chi-square test.Results: Experiment 1: In counting the tick mortality percentages on the second day after application in group 1: control was 37.5%; 2: 72.5%; 3: 80%; 4: 92.5%, on day 7 and day 8 there was no difference with 90% and 100% mortality. Experiment 2: The soils positive to EPN were 35% Non-livestock and 25% Livestock.Limitations on study/implications: it is important to make producers aware of the correct use of chemical products.Findings/conclusions: R. microplus was susceptible to coumaphos in cattle production units. A greater presence of EPN was found in non-livestock soils, which may be related to the use of chemical products to control parasites.
