NOTES ON TABANUS ATRATUS SUBSP. 
NANTUCKENSIS HINE (DIPTERA) 
By Norman S. Bailey 
Biological Laboratories, Harvard University 
In the course of my field work with the saltmarsh 
Tabanidae during the summers of 1946 and 1947 some 
observations were made on this representative* of the 
black horsefly which occurs along the coast from New 
Hampshire to New York. Although adults are never 
abundant, their large size and noisy flight make them 
conspicuous on the marshes. During the 1947 season 
(from late May to September 11th) only 16 specimens 
(5 males and 11 females) were taken whereas hundreds of 
Tabanus nigrovittatus Macquart (Bailey, 1947) could 
readily be captured in a short time on almost any day 
from early July to late August. The first specimen, a 
male, was collected on July 12th on the Pine Island Marsh 
in Newbury. Stone (1938) notes June 19th as the earliest 
record at Dorchester, Massachusetts and Johnson (1919> 
gives the other seasonal extreme of September 8th at 
Rochester, New Hampshire. My latest record is a female 
from Pine Island on September 11th. There is something 
of interest in the fact that all of my earlier 1947 captures 
were males. The second one was taken at Ipswich on 
July 16th, two more on July 24th at Newbury, and the 
final male at the last mentioned locality on August 27th. 
Females, possibly of this subspecies, were seen annoying 
horses in a field above the Parker River saltmarshes on 
July 15, 1946. In 1947, however, the first female was ob- 
served, in the act of ovipositing, on August 19th. From 
that day until September 8th one or two were seen, and 
usually taken, on each of my almost daily trips to the 
marsh. 
Pine Island is a partly wooded knoll, large enough for 
a few cottages, that lies in the midst of the saltmarsh 
somewhat less than half-way from the mainland proper 
to Plum Island. It is about a half of a mile from the up- 
* My thanks to Dr. Joseph C. Bequaert for this determination. 
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