Avaliação de óleos essenciais de capim limão, citronela e eucalipto no controle do carrapato

Abstract

This research was aimed at evaluating in vitro and in vivo effects of lemongrass (Cymbopogon flexuosus Stapf.) oil, citronella (Cymbopogon winterianus Jowitt) oil and eucalyptus (Corymbia citriodora) oil on cattle ticks (Rhipicephalus (Boophilus) microplus), each of which corresponds to an essential oil experiment. Negative control group end eight concentrations of lemongrass oil, citronella oil and eucalyptus oil (0.5; 1; 2; 5; 10; 20; 50; 100%), were used on in vitro trials with engorged female ticks. The efficacy control ticks was 0; 20; 39; 99.5; 100; 100; 100; 100 and 100%, for lemongrass oil, of 0; 34.5; 43; 48; 82; 99; 99; 100 and 100%, for citronella oil and 0; 30.5; 75.5; 91; 100; 100; 100; 100 and 100%, of oil, respectively. On in vivo trial eighteen Holstein cows were allocated to three groups for each treatment (negative control, essential oil - level estimated by regression analysis, accounting for 95% efficacy of control ticks on in vitro trial and amitraz at 0.025%). Engorged female ticks were counted before (mean of days -3, -2, -1) and after treatment (1, 2, 3, 5, 7, 10, 14, 21 days). Twenty one days after application of the products, the efficacy on control ticks was 0; 54 (lemongrass oil at 2%) and 74.5%; of 0; 91.3 (citronella oil at 8.6%) and 60%; and 0; 96.4 (eucalyptus oil at 3.5%) and 69%, respectively for in vivo treatments. On the 1st and 2nd milked after treatments, physiologic variables were evaluate and milk samples were collected to evaluate organoleptic properties in milk and yoghurt (negative control x phytotherapic treatment). Similar results were found with sensorial acceptance test of milk and physiologic variables, in the three in vivo experiments.