SIMULIIDM 



8ii 



and 5. hirtipes Fries are known in Scotland. S. columhaczense 

 Schonberg, locally known as the ' banat/ is the cause of much 

 destruction of cattle in South Hungary. S. indicum Becher is 

 the ' dam din ' of Assam, which is a cause of irritation to tea- 

 coolies. S. damnosum Theobald in Uganda, where it is called 

 'mbwa,' and in the Sudan, where it is called 'kunteb'; and 

 5. griseicollis Becker, of Dongola, locally called ' nimetta,' are very 

 virulent. Austen says that the ' potu ' flies were accused of having 

 caused the death of coolies while constructing an Indian road. 

 The effects of the bite of these small insects is most irritating, and 

 the appearance of a person after a severe attack is most peculiar, 

 the face and hands — i.e., the exposed parts — being covered with 

 papules. 



Life-History.— The eggs are deposited on stones or plants in 

 running water. The larva is broad posteriorly, where it possesses 

 a sucker, capable of attaching it to any convenient object. An- 

 teriorly it has two fan-like organs. It moves about in the water 



after the manner of a leech, and also by the aid of a silken thread 

 which it spins. It feeds on water plants. The larval stage lasts 

 about a month, when a cocoon is spun, inside which the pupa is 

 formed. The pupa breathes by means of branched filaments, and 

 at the end of a week becomes the imago, which is carried to the 

 surface of the water in an air-bubble. 



Habits. — 'The SiMtdiidce live in the open country, and very 

 rarely enter houses. They can be found in the early morning, or, 

 better, in the late afternoon, flying in clouds. During the day- 

 time they can be found on trees, grasses, etc. It is common to 

 find the males quite close to the streams in which the eggs, larvae, 

 and pupae abound; but the female can apparently travel for con- 

 siderable distances in search of food, and can quite easily be caught 

 on the wing. They may also be found in the ears of cattle, donkeys, 

 etc., where they feed. They are not all vicious, blood-thirsty 

 insects. Thus, for example, S. venustum Say is said to be quite 

 peaceably disposed. It is quite possible that in some instances 



Fig. 404. — Simulium reptans Latreille: Female. 



