176 



BLACK-FLIES. 



which flies with great force so that it can be felt when strik- 

 ing the face. It seems that it does not care much for human 

 blood, but it irritates considerably by being of a ver\' in- 

 quisitive nature, even entering mouth, nose, ear and \vhat is 

 worse, the eye. If horses are left standing for some time in 

 the roads, the^^ are apt to become restive, shake their heads 

 in a violent manner, frequently stamping and snorting at 

 the same time. If the ears of the horse are inspected we 

 usually find the cause of their irritation in a large number of 

 such small flies, which are busily engaged in sucking the 



Fig. 144. — ^imuUiim decorum. Female. Greatlj- enlarged. Original. 



blood, and they do so by inserting their powerful piercing 

 organs into a vein, hence they seem to be arranged in regular 

 rows. If not occurring in ver\^ large numbers the3^ cause but 

 little harm, and an application of a little grease rubbed to- 

 gether with a few drops of carbolic acid, soon remedies the 

 evil, and drives away other intruders. According to 

 Coquillett, who kindly determined a number of species of 

 this genus for the writer, it is an undescribed species. On 

 account of its very small size the name of SinuiUum mitiutum 

 is proposed. The female insect is illustrated in fig. 145; the 

 male has not been seen. This species flies from May 15 to 



