230 FLEAS, FLUKES AND CUCKOOS 



The lives of the Ixodidae are far more precarious than those of the 

 Argasidae — a fact which is reflected in their greatly increased egg out- 

 put, the females laying in thousands instead of hundreds. 



Ticks are the great exponents of the gentle art of waiting. An adult 

 can wait from four to seven years for a meal and even a young larva will 

 survive six months without feeding. The great food reservoirs (for the 

 host's blood) in their branching intestines makes this extraordinary 

 endurance feat possible. Both sexes sometimes wait many months for a 

 mate and finally when they come together copulation can last over a week. 



On emerging from the egg the larva has only six legs and is known 

 as a seed tick. It has to wait for a passing host in order to obtain the 

 first blood meal. Subsequently it drops to the ground or back into the 

 nest and moults into an eight-legged nymph. Again it has to wait for 

 the host and another blood meal, after which it once more drops to 

 the ground and moults, this time emerging as a fully mature tick 

 (Plate XXXIIb). Yet another wait for the host follows. 



The familiar sheep tick {Ixodes ricinus), feeds equally well on a large 

 variety of mammals including stoats, red deer, rabbits, squirrels, mice 

 and even hibernating hedgehogs. In fact it will attack any warm- 

 blooded animal with which it comes into contact. It has been recorded 

 from many birds, and favours ground-feeding and ground-nesting 

 species like grouse, larks and meadow-pipits, but it has also been taken 

 from the long-eared owl, whinchat, redwing, blackbird, rook, lapwing, 

 chaffinch — altogether from 47 different British birds. 



It is generally located on the head of an avian host, attached near 

 the eye or the angle of the mandibles, where it cannot be pecked off. 

 After engorging for a few days on the bird the female drops off to lay 

 her eggs, but an unfertilised female is incapable of finishing her meal 

 and remains attached, sometimes for weeks and months until found by 

 the male, who quickly puts an end to her dreary repast. 



Copulation between ticks is most peculiar. The male enlarges the 

 female sex orifice with his rostrum — a surgical operation which takes a 

 considerable time — and then with the aid of his mouth-parts introduces 

 a packet of his own sperm inside the female. Soon afterwards he dies. 



In most Ixodidae it is the male which actively seeks the female, but 

 sometimes the roles are reversed. Again there are those curious cases 

 where no male has ever been found and the eggs develop partheno- 

 genetically. In rare instances the males, which are dwarfed, are parasitic 

 upon the females, and suck the host's blood via the body of their mates. 



