PARASITES OF WILD GROUSE 



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larger than males and the color when engorged is a reddish brown. Young and unengorged 

 individuals are much smaller and lighter in color. Identification of ticks to species requires 

 the services of specialists in this line. 



Life History and Dissemination. From the eggs of the ticks which are deposited on the 

 ground, small six-legged "seed" ticks hatch. These climb upon vegetation and wait for contact 

 with a suitable host. After attacking themselves thereto and feeding for some time, these 

 larvae drop to the ground and undergo a period of relative inactivity. From this they emerge 

 as 8-legged forms known as nymphs. These forms also must contact a host on which to feed. 

 Later they too, fall to the ground where a final transformation into adults takes place. The 

 adults become attached to a third host, on which mating takes place. Pregnant females like- 

 wise return to the ground to lay their eggs after which they shortly die. Although adult ticks 

 have their preferred hosts, they are sometimes found on a number of species which they do 

 not inhabit commonly. In general, the larvae and nymphs are not as particular as are the 

 adults in the selection of hosts. They may therefore be found on many different animals. This 

 ability to utilize a number of different species is of particular importance in the maintenance 

 and dissemination of ticks which do not remain on the same animal through all stages, since 

 in dropping to the ground to moult the parasites run a risk of not being able to contact an- 

 other host when the time comes for subsequent engorgement. 



Pathogenicity. Ticks gain their sustenance by sucking blood and during this process may 

 set up considerable inflammation and irritation at the site of their attachment. They are pre- 

 sent on both chick and adult grouse during the summer. 



BIRD TICKS ( Haemaphysalis chordeilis) ATTACHED to head and neck of adult grouse 



