HOVERING MALES OF HYBOMITRA CINCTA 
(FABRICIUS) (DIPTERA, TABANIDJE) 
By Norman S. Bailey 
Boston University 
In a recent paper (Annals, E.S.A., December, 1948) 
I reviewed the literature dealing with the hovering and 
mating of Tabanids. The observations recorded in this 
item corroborate the opinion then expressed that hover- 
ing is primarily a male activity among the horseflies. 
Brimley and Sherman (1908) had previously noted the 
males of this species so engaged. The following data 
reveal some of the conditions under which Hybomitra 
cincta (Pabr.) hovers. 
During the 1948 season I was regularly in the field 
from early June until October. On July 7th I was pleased 
to observe and net a hovering male of Hybomitra cincta 
at a station that I had recently discovered to be of con- 
siderable entomological interest in other respects. Con- 
sequently, an effort was made to visit the locality at 
frequent intervals throughout the summer and early fall. 
Specimens of H. cincta were seen and taken on nine oc- 
casions from July 7th to July 29th inclusive. After the 
last date mentioned none were seen. There were a few 
days within the period indicated when none of them was 
observed. Of further interest is the fact that not one 
female was captured, although, with only one or two 
exceptions, every fly of that species was successfully 
netted. Probably females were not far away, however. 
A total of 28 hovering males were taken. Seven is the 
largest number captured on any one day. The accom- 
panying table shows that they hover from 8 :30 to 9 :40 
a.m. and from 1:30 to 5:10 p.m. (Eastern Daylight 
Saving Time.) 1 However, no flies were taken between 
10 a.m. and 1 :30 p.m. Tabulated field notes also suggest 
that hovering goes on within rather wide limits (for the 
1 One hour later than Eastern Standard Time. 
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