The extent of the spread is not known, but many more cattle are probably infested than have been reported. Parasitic larvae and nymphs of this species cause serious damage to livestock. They attach in the inner folds of the outer ear and suck blood. The wounds may become infected with pus-forming organisms that give rise to a condition known as canker ear. The constant irritation causes animals to become dull, unthrifty and even to lose weight.
Infested animals shake their heads and rub their ears in an attempt to relieve the irritation.
The ticks are not vectors of disease. Infestation is spread by introduction of an infested animal or animals into previously uninfested herds. Bulls and replacement heifers that are to be kept for some time are most likely to be involved. Since the nymphs may remain in the ear for four months, any animal kept on a farm for that period of time could provide the source for infestation of the whole herd. Back To Top Tick Control Ticks thrive in high humidity conditions.