A spotlight on spotted fever
In Australia the most common tick that bites humans is the ixodid tick, and along the eastern seaboard the most common species is Ixodes holocyclus. This often goes by names like ‘paralysis tick’, ‘shellback’ or ‘seed tick’.
Ixodid ticks go through three stages. Eggs hatch to become larvae which have six legs. Following a blood meal, the larva hatches into a nymph with eight legs. Nymphs develop into adults (also with eight legs) following a blood meal.
Larvae and unengorged nymphs can be extremely small, so magnification is often needed to distinguish the two stages. Adults are easily seen. Females require a blood meal to develop and lay eggs. Adult males just ‘cruise around’ looking for females to mate with. While the presence of all three stages may overlap at any one time in tick endemic areas, commonly around Easter time larvae are in abundance