Effect of coumaphos on Rhipicephalus microplus and entomopatho-genic nematodes in cattle production units

Abstract

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.