PROC. ENT. SOC. WASH., VOL. 20, NO. B, JUNE, 1918 125 



very dry. T. americanus are very rare; only single individuals 

 were seen daily. T. trijunctus are rare, but T. melanocerus com- 

 mon. T. lineola was more numerous than in late April. The 

 brown Tabanid (T. turbid us) was rare. 



T. flavus was quite numerous at dawn and dusk around the 

 house; none have ever been observed in the hammock or low 

 shrubbery along the roadway, nor on blossoms. 



I have observed a small Tabanid of about the same size as T. 

 lineola, but of a lighter color and with entirely green eyes, with one 

 dark line transversely across the eyes. Very few individuals 

 were observed and it was very shy. 



SUMMARY. 



The flight at dawn of the large gadfly (T. americanus) at 

 Paradise Key in the Lower Everglades in enormous numbers has 

 been observed for two years. In 1917 it was thought that both 

 males and female were in flight. This year's observations indi- 

 cate that most of the flies "swarming" are males. Possibly 

 females are ttracted by the noise and dart in to mate. F. 

 Knab states that this occurs among mosquitoes. The habit 

 that the flies have when hovering of darting towards each other 

 and clinging may be mating. Due to the height at which the 

 adults fly this has not yet been confirmed ; only half a dozen adults 

 have been so far caught hovering low and they were all males. 



It is believed that the flies when hovering reverse and hover 

 upside down with abdomen pointed upwards and legs sticking up. 

 In 1918 the swarm was first observed on March 9 and ended May 

 10. 



Males of several species of Tabanus congregate in large numbers 

 during the day time and feed on the blossoms of the saw palmetto 

 (Serenoa serrulatn) where the bloom is shaded. 



Tabanus lineola was found "swarming" at dusk on May 10. 



The beautiful greenish yellow night flying T. flavus are common. 



A few Tabanid larvae were found in the water and muck under 

 sawgrass near Paradise Key. 



Twelve species of Tanabus have been collected at Paradise Key. 

 While exlremely annoying, they are beautiful insects. The large 

 eyes of male T. americanus are a brilliant light green. Those 

 of males of T. trijunctus are lavender and those of the females 

 purple banded. 



The yellow fly of the Dismal Swamp (Diachlorus fn'ru</<i/nx) 

 also occurs at Paradise Key, as well as several species of deerflies 

 (Chrysops). 



The following is a list of Tabanidae collected at Paradise Key, 

 Fla., with the dales of their occurrence. These flies were de- 

 termined bv C. T. Greene. 



