OTHER TICKS 31 



EXERCISE 17b 



THE TICKS 



ORDER ARACHNIDA, FAMILY IXODIRffi 



Systematic Study. 

 Family Ixodidae. 



A. Subfamily Ixodinae, scutum present, pulvilli present, 

 mouthparts projecting in front. 



a. Examples: Mar gar opus annulatus, Texas fever tick or blue 

 tick, scutum uniformly chestnut brown in color, labium or 

 hypostome with eight rows of teeth. Front pair of legs emerging 

 from the shoulders. What is the form of the guard plates of the 

 spiracles? 



b. Dermacentor variabilis, American dog tick, scutum spotted 

 with silver. Front pair of legs emerging close to capitulum. 

 What is the form of the guard plates of the spiracles? 



B. Subfamily Argasinae, scutum absent, pulvilli absent, 

 mouthparts hidden under body. 



a. Examples: Argas miniatus, American poultry tick, body 

 flat with thin edges, body oval, with rectangular marginal fes- 

 toons. 



b. Ornithodorus megnini, the spinous ear tick, body lyre- 

 shaped and covered with spines. 



Draw from specimens, using hand lens or binocular micro- 

 scope the three species not previously drawn. 



EXERCISE 18a 



OTHER TICKS 



As far as it is possible to secure material examine specimens of 

 the following species of ticks, taking notes and making drawings 



