-76- 



Parman (1919) noted that the abundance of j.u. diabol ica in the 

 fall was extremely variable, ranging from only one specimen attacking 

 in several nights, to 25 to 30 attacking each night for a short 

 period. This variability in numbers and peak time of attack was 

 observed both in the spring and fall during this study, and appears to 

 be strongly influenced by ambient temperatures, relative humidity and 

 air movement. Sand flies were observed in greatest numbers on hot 

 humid nights (27°C or above and 70% or greater RH) with little or no 

 air movement. Not surprisingly, air movement seemed to affect their 

 presence the most, as numbers decreased dramatically with an increase 

 in wind velocity above 8 kph (5 mph). Foraging sorties or wave 

 attacks such as described previously did not occur except on hot, 

 humid and windless nights. Ki 1 1 ick-Kendrick and Rioux (1981) reported 

 the peak biting activity of P. ariasi may be delayed because of wind 

 or suppressed by storms or a fall in temperature below about 16°C. 

 Some workers have studied the effects of wind on the movement and 

 activity of sand flies but probably overestimated the wind speed at 

 which activity ceased (Ki 1 1 ick-Kendrick and Rioux, 1981). 



Blood-fed females have greater difficulty flying than unfed 

 females and apparently rest in protected sites for up to 24 hrs to 

 allow for diuresis and partial digestion of the blood-meal. This 

 accounts for the large number (31 to 46%) of blood-fed females taken 

 in latrine resting stations. 



Both male and female Lu. diabolica are assumed to disperse 

 from their breeding sites, possibly in search of sugar or a blood- 

 meal. Their attraction to light draws them close to human dwellings 

 where other shorter range attractants, such as exhaled CO2 



