the more favourable areas for the tick in sub-tropical Queensland. Amblyomma variegatum was subject to a multi-country eradication program in the Caribbean area, but it failed for complex economic and political reasons. Biological and ecological based methods in control of ticks and transmitted microbes Cattle breeding for disease resistance Breeding for resistant cattle has been successful for their ability to acquire strong immune resistance to Rhipicephalus microplus following natural exposure to these ticks. Commercial breeds of cattle (examples: Australian Friesian Sahiwal and Australian Milking Zebu) are successful in the relevant environment. Only a few commercial breeds of tick-resistant cattle are available. These breeds were developed under laboratory conditions where bulls were selected for good ability to acquire immune resistance to ticks, and cows were selected for heat tolerance and milk yield. The scope for selecting cattle under farm conditions includes culling those animals persistently with heavy infestations of ticks. This is due to a characteristic of many parasitic infestations where in a population of hosts, a few individual hosts carry heavy infestations, whilst the majority are lightly infested. This is called an overdispersed, or aggregated, distribution; it may be caused by individual variation in immune competence, which has a genetic component. Pasture management For farms infested with R. microplus in Australia and South America, rotation of pasture can kill the questing larvae. Pasture management is feasible for control of these one-host ticks because the only stage that quests for hosts on vegetation is the larval stage. Because of their small size, larvae are highly susceptible to dehydration and starvation, so a period without access to hosts of about 2 months can be effective. The nymphs and adults of three-host ticks, such as Amblyomma and Rhipicephalus species, can live for many months to a year or more, respectively, whilst questing on the vegetation. Thus, controlling them by pasture management is usually not practical. In addition, farmers find the priority to provide their stock with good feed often conflicts with the regimens for pasture rotation for tick control. Ticks affecting dogs and other companion animals around private houses are reduced by clearing of vegetation and leaf litter, mowing grass short, and fencing out deer and other wild animals that bring in ticks. Epidemiological factors Compared to other arthropods of veterinary and medical importance, most species of ticks are long-lived over their whole lifecycles. Ixodes species in cool, temperate climates typically take one