NO. I 



BLACK FLIES OF GUATEMALA — ^DALMAT 



405 



9WI00 61-90 71-80 61-70 SI-60 41-90 81-40 



"* RANGE OF RELATIVE HUMIDITY 



Fig. 20. — Eflfect of relative humidity on biting activity of Siniuliiim (S.) metal- 

 licum. (Prepared on 3-cycle semilogarithmic paper.) The flies were collected 

 while feeding on human subjects who were exposed to bites on 69 days from 

 6 : 30 a.m. until S : 30 p.m. Relative humidity was recorded every 30 minutes. 

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

 that was either shaded or exposed to the sun. 



CC 

 UJ 



SHOO 8I«90 71-80 61-70 



91-60 41-SO 



RANGE OF RELATIVE HUMIDITY 



Fig. 21. — Effect of relative humidity on biting activity of Simuliuni (L.) cal- 

 lidnm. (Prepared on 3-cycle semilogarithmic paper.) The flies were collected 

 while feeding on human subjects who were exposed to bites on 69 days from 

 6 : 30 a.m. until 5 : 30 p.m. Relative humidity was recorded every 30 minutes. 

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

 that was either shaded or exposed to the sun. 



