Boophiuls micropuls (Canestrini,1887): Susceptibilidade, uso atual e retrospectivo de carrapaticidas em propriedades das regiões fisiogeográficas da baixada do Grande - Rio e Rio de Janeiro. Uma abordagem epidemiológica

Abstract

Samples of Boophilus microplus from eight properties located in the physiogeographic regions of Greater Rio de Janeiro, Brazil, were studied in the adult phase in field and laboratory tests and the larval phase in the laboratory as to t h e i r l e v e l s of s e n s i t i v i t y to p y r e t h r o i d - b a s e a c a r i c i d e s . The existence of a focus resistant to these products at the Itaguaí Experimental Station PESAGRO-RIO was shown to be related to the intensive use of pyrethroid-base products such as deltamethrin and alphamethrin, used for a period of four years. The tick samples coming from perifocal properties were sensitive to all the pyrethroid-base products, although some sensitivity changes were observed when compared to ticks of sensitive strains on some properties. However, these less sensitive to an amidine base product than strains from the r e s i s t a n t focus. One of the points observed was that economic priorities always prevailed over the sanitary priorities on the properties where samples of t i c k s were c o l l e c t e d . XXV. On the other hand, knowledge of the biology and methods used for the control of B. microplus and the information necessary for the adoption of effective practices of control were insufficient. The production system observed on the properties favors an increased parasite load on the herds, causing a high spray wash frequency, which may be responsible for selection of resistant ticks within a short to midterm range.