482 



DIPTERA 



CHAP. 



AVilliston states that 1400 or 1500 species are named, is 

 well known to travellers on account of the blood - sucking 

 habits of its members ; they have great powers 

 of flight, and alight on man and animals, and 

 draw blood by making an incision with the 

 proboscis ; only the females do this, the 

 males wanting a pair of the lancets that 

 enable the other sex to inflict their for- 

 midable wounds. They are comparatively large 

 Insects, some of our English species of Tdbanus 

 attaining an inch in length. The smaller, grey 

 Haernatopota, is known to every one who has 

 walked in woods or meadows in the summer, as 

 it alights quietly on the hands or neck and 

 bites one without his having previously been 

 made aware of its presence. The larger Tabani 

 hum so much that one always knows when an 

 individual is near. The species of Chrysops, in 

 habits similar to Haematopota, are remarkable 

 for their beautifully coloured golden-green eyes. 

 In Brazil the Motuca fly, Hadrus lepidotus, 

 Perty, makes so large and deep a cut that con- 

 siderable bleeding may follow, and as it some- 

 times settles in numbers on the body, it is 

 deservedly feared. The most remarkable forms 



FIG. 229. Pangonia f 



longirostris. x ot labaniclae are the species 01 the widely dis- 

 HardScke \^ tributed genus Pangonia (Fig. 229). The pro- 

 boscis in the females of some of the species is 

 three or four times the length of the body, and as it is stiff and 

 needle-like the creature can use it w T hile hovering on the wing, and 

 will pierce the human body even through clothing of considerable 

 thickness. The males suck the juices of flowers. The Seroot 

 fly, that renders some of the districts of Nubia uninhabitable! 

 for about three months of the year, appears, from the figure and 

 description given by Sir Samuel Baker, to be a Pangonia. 

 Tabanidae are a favourite food of the fossorial wasps of the 

 family Bembecidae. These wasps are apparently aware of the 

 blood-sucking habits of their favourites, and attend on travellers 

 and pick up the flies as they are about to settle down to their 

 phlebotomic operations. The larvae of the Tabanidae are some 



