118 DIRECT INJURIES CAUSED BY INSECTS. 



From Humboldt also we learn that " between the 

 little harbour of Higuerote and the mouth of the Rio 

 Unare the wretched inhabitants are accustomed to stretch 

 themselves on the ground, and pass the night buried in 

 the sand three or four inches deep, leaving out the head 

 only, which they cover with a handkerchief." This illus- 

 trious traveller has given an account in detail of these 

 insect plagues, by which it appears that amongst them 

 there are diurnal, crepuscular, and nocturnal species, or 

 genera : the Mosquiios or Simulia flying in the day ; 

 the Temporaneros, probably a kind of Culex, flying 

 during twilight; and the Zancudos or Culices in the 

 night. So that there is no rest for the inhabitants 

 from their torment day or night, except for a short in- 

 terval between the retreat of one species and the attack 

 of another. We learn from this author that the sting 

 or bite of the Simulium is as bad as that of the Stomoxys 

 before noticed 8 . 



It is not therefore incredible that Sapor, king of Per- 

 sia, as is related, should have been compelled to raise 

 the siege of Nisibis by a plague of gnats, which attack- 

 ing his elephants and beasts of burthen, so caused the 

 rout of his army, whatever we may think of the miracle 

 to which it was attributed 15 ; nor that the inhabitants of 

 various cities, as Mouffet has collected from different au- 

 thors c , should, by an extraordinary multiplication of 

 this plague, have been compelled to desert them; or 

 that by their power to do mischief, like other conquerors 

 who have been the torment of the human race, they should 



, a Humboldt's Personal Narrative, E. T. v, 87-. 

 11 Theodorit, Hist. Eccl. 1. ii. c. 30. 

 c Mouffet, 85. Amoreux, 119, 



