Comparative efficacy of several insecticides for control of cattle lice (Mallophaga : Trichodectidae and Anoplura : Haematopinidae)

Several insecticides were applied to cattle at various rates, mixtures, app lication methods and numbers of treatments and evaluated for control of cat tle lice. The insecticides included permethrin at various rates as a pour-o n with and without the synergist piperonyl butoxide (PBO), and also at vari ous rates as a spray with and without PBO. Pirimiphos-methyl was evaluated as a pour-on at various rates and with one or two applications. Lambda cyha lothrin in microencapsulated formulation was compared to a non-microencapsu lated formulation. Rabon(R) was applied as a pour-on at two rats and at one or two treatments for each rate. Dimilin(R) was applied at a pour-on at tw o rates and mixed with permethrin and applied at tow rates. Five endectocid es, Eprinex(R), Ivomec(R), Dectomax(R), Cydectin(R) and Phoenectin(R) were all applied at the same rate. The cattle utilized in this research were all infested with a mixture of lice species. The species included: Bovicola (D amalinia) bovis (L.), Haematopinus eurysternus (Nitzsch), Linognthus vituli (L.) and Solenoptes capillatus (Enderlein). Most of the cattle were infest ed with at least two species and some had three or all four species present . All of the treatments except permethrin 1.0% + 5% PBO, at a rate of 3 ml/ 45.4 kg wt, provided acceptable lice control with one application. Data ind icated that applying the insecticides in early January should provide enoug h control to render the need for a second treatment unnecessary. (C) 2001 E lsevier Science B.V, All rights reserved.