Diseases of cattle, sheep, goats Diseases of cattle, sheep, goats and swine diseasesofcattle00mous Year: 1920 LOUPING-ILL. 433 The Larva. When first hatched out from the eggs, which are sup- posed to be laid at the roots of coarse herbage, the young ticks are white and soft, but soon gain strength. Provided the weather is favour- able, they climb up the stems, and, holding by their two posterior pairs of legs, await the passing of a host, employing their two front legs as insects use their antennae. In this, as in other ' free living ' stages of their existence, the young larvae show great a
Diseases of cattle, sheep, goats Diseases of cattle, sheep, goats and swine diseasesofcattle00mous Year: 1920 LOUPING-ILL. 433 The Larva. When first hatched out from the eggs, which are sup- posed to be laid at the roots of coarse herbage, the young ticks are white and soft, but soon gain strength. Provided the weather is favour- able, they climb up the stems, and, holding by their two posterior pairs of legs, await the passing of a host, employing their two front legs as insects use their antennae. In this, as in other ' free living ' stages of their existence, the young larvae show great activity, attaching themselves and clinging tenaciously to any moving object. They appear to be more numerous on the rank rushes growing in damp, undrained places. On finding a host, larvae attach themselves by the rostrum, and remain there for about two days, by which time they are distended, black and globular. At this time they are easily detached from the host, and have lost their activity and clinging habits. The Pupa. The possession of eight legs dis- tinguishes the pupa easily from the larva. The extra pair are placed behind the others. After the metamorphosis, the pupa takes up its posi- tion on the stalks of herbage, just as the larva had done, for another chance of attachment to a host. But whereas adult grass ticks seem to confine themselves mostly to sheep, cattle, and deer, the larvae and pupae attach themselves very readily to various hosts, such as horses, dogs, and even human beings. After about four days the pupa is again replete with blood, black and opaque, and again drops to the ground to undergo its second and final change. Adults. On reaching the adult age, both males and females again wait on herbage for a passing host. At this time, as well as after dis- tension of the female on the host, an action which appears, to be sexual intercourse freely takes place, even in confinement. On the host the females gradually distend (Fig. 202), and in the course of so
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