192 PROC. ENT. soc. WASH., VOL. 21, NO. 8, NOV., 1919 



mals were covered with bagging for protection against these gad- 

 flies. 



From April 23 to 30 the flight continued to be normal. On 

 April 25 the screen door of the veranda was left open for two 

 hours following sunrise and 60 T. americanus, 323 T. trijunctiis, 

 84 T. lineola and 3 T. flavus female adults were captured. One 

 female adult of T. turbidus was also captured. 



On May 1, after a heavy afternoon rain on April 30, there was 

 one of the heaviest flights of the season. Rain seems to increase 

 the flight. Evidently fresh adults were just emerging and could 

 be heard trying out their wings. 



Normal flights occurred on May 2, 3, 4 and 5; the flights always 

 being stronger on bright, fair dawns than on foggy, cloudy or 

 misty mornings, the duration of the flight being governed by 

 the rapidity of dawn. May 6-11 saw the flight decreasing in 

 strength, females were in evidence but males were still numerous 

 in the shade of the hammock. On May 5 a few female adults of 

 T. flavus were collected on the veranda screen. 



On May 12 there was a drizzling rain and no flight. May 13 

 dawned foggy and the flight was very short and not as strong 

 as usual. 



There was a normal flight on May 14, although the adults were 

 decreasing in numbers; there was heavy rainfall in the evening 

 and night. 



On May 15 there was a very light flight owing to the damp 

 atmosphere. May 16 dawned clear but there was a perceptible 

 waning of the flight of the large gadfly. The loud "roaring 

 swarming" was past for the season but there were still "strag- 

 glers" present in the hammock. While this flight lasted in 1919, 

 it was even stronger than in former years. Other gadflies, Ta- 

 banus trijunctus and T. lineola, as well as "deerflies" (Chrysops), 

 were still abundant and annoying. Mosquitoes were now pres- 

 ent and also made life interesting. 



By May 17 the flight was declining in volume daily; the females 

 were more abundant than the males. 



From the 18th to 22nd the flight was decreasing and was of 

 very much shorter duration lasting-only 9 minutes on May 18. 



On the 23rd the flight was noted only over the densest portion 

 of the hammock. 



There was a very small flight on May 24 only 3 adults were 

 observed hovering and a few more were heard. 



During the week of May 25 to 31 there was no flight of T. 

 americanus. An occasional male could still be observed on flow- 

 ers and quite a few females were in evidence. T. lineola adults 

 were not so numerous. T. atratus was more in evidence than 



