 This arrested development is called "hypobiosis", and can last for up to six or seven months.Studies suggest that the inhibition process in "O. ostertagi" depends on the weather conditions to which the infective L3 larvae are exposed on pasture, and the length of time that L3 larvae spend on pasture.In temperate regions of the northern hemisphere, hypobiosis occurs in autumn and early winter, but in the southern hemisphere there is evidence that this phenomenon occurs in spring and early summer.