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<I3 I& IS 17 19 21 23 25 27 29 i\ 33 35 37 39 40> 



TEMPERATURE (DECREES CENTIGRADE) 



Fig. i6. — Effect of air temperature on biting activity of Simulium (S.) 

 ochraceum. (Prepared on 4-cycle semilogarithmic paper.) The flies were col- 

 lected while feeding on human subjects who were exposed to bites on 95 days from 

 6 : 30 a.m. until 5 : 30 p.m. The air temperature was recorded every 10 minutes. 

 Sun or shade readings indicate that the flies were biting on a part of the body 

 that was exposed to either the sun or shade. 



SUN READINGS 

 SHADE READ1NQ3 



.1 



<IS 13 



19 21 23 26 27 29 31 33 39 37 39 40> 



TEMPERATURE (DEOR&ES CENTIQRADE) 



Fig. 17. — Effect of air temperature on biting activity of Simulium (S.) mctal- 

 licum. (Prepared on 4-cycle semilogarithmic paper.) The flies were collected 

 while feeding on human subjects who were exposed to bites on 95 days from 

 6: 30 a.m. until 5: 30 p.m. The air temperature was recorded every 10 minutes. 

 Sun or shade readings indicate that the flies were biting on a part of the body 

 that was exposed to either the sun or shade. 



403 



