Cattle lice in New Zealand: observations on the prevalence, distribution and seasonal patterns of infestation

Studies were made of the louse populations on 364 cattle of various ages and breeds in 19 herds. Eleven herds were infested with Damalinia bovis and 15 with Linognathus vituli. Neither Haematopinus eurysternus nor Solenopotes capillatus were encountered though both have been recorded in New Zealand. D. bovis and L. vituli occur throughout New Zealand with D. bovis more prevalent on beef breeds and L. vituli on dairy breeds. In herds where observations covered the entire winter it appeared that L. vituli populations tended to peak earlier (June/ July) than those of D. bovis (August/September). Both species were most abundant on animals of up to approximately one year of age; only older cattle that were diseased or inadequately fed carried substantial burdens. Within herds, lighter cattle tended to carry more lice than heavier ones. Animals kept on a low plane of nutrition were more heavily infested than those on a higher plane.