DEPARTMENT OF AGRICULTURE, 



NEW SOUTH WALES. 



SCIENCE BULLETIN, No. 3. 



MARCH FLIES. 



WALTER W. FROGGATT, F.L.S., Government Entomologist. 



THE family Tabanidke is one of the most important groups of the flies from 

 an economic point of view, in habits, range, and numbers. In the latest 

 list of Diptera, about 1,800 species have been described, of which the 

 typical genus Tabanus contains half, or 900 species, from all parts of the 

 world, and in this number are included forty-eight species found in 

 Australia. 



These biting flies are commonly known in the Australian bush as " March 

 Flies," under the impression that they appear in March; but though usually 

 most abundant towards the end of summer, they can be found in suitable 

 localities all through the warmer months of the year. In England their 

 popular name is " Breeze Flies," on account of their loud hum when, flying; 

 or " Gad Flies," on account of their blood-sucking propensities, and the 

 way they annoy horses and cattle in their resting-places. In America they 

 are known as " Green Heads," from the usual deep green tint of their very 

 large eyes; and in some districts simply as " Horse Flies." 



These flies are well known in the bush, not onh^ from the savage way in 

 which they fasten on one's horse to suck up blood, but also from the per- 

 sistent manner in which they settle upon the hands and neck of the traveller, 

 and allow themselves to be killed in their eagerness to draw blood. 



The typical March Fly is of a uniform greyish brown, or dull-yellow 

 tint, marked with brown; the abdominal segments barred or blotched with 

 darker tints. The head is large, the greater portion taken up with the large 

 eyes, which in the males almost meet at the front of the head. ' The 

 thorax is well defined, as broad as the body, and fitting close against the 

 head along the front margin. The wings are large, strongly veined, and 

 adapted for sustained flight; the legs stout; and the abdomen of a uniform 

 width from the hind margin of the thorax to the rounded tip of the abdomen, 

 and somewhat flattened on the dorsal surface. 



The male March Flies live upon the sap of plants, the honey-dew exuded 

 by homopterous insects, aphids, &c. ; and they sometimes ' attack aphids and 

 other soft-bodied insects and suck up their blood ; but it is only the female 

 flies that have the true blood-sucking instinct. Like mosquitoes " and other 

 blood-sucking flies, it is probable that the r females, in ^ defrft of 'blood, 

 adopt the habits of the males, 1 and live upon vegetable s'dp. 



