82 MENDlZA. 



thg main body was impervious to sight ; they were 

 not, however, so thick together but that they could 

 escape a stick waved backwards and forwards. 

 When they alighted, they were more numerous 

 than the leaves in the field, and the surface became 

 reddish instead of being green : the swarm having 

 once alighted, the individuals flew from side to side 

 in all directions. Locusts are not an uncommon 

 pest in this country : already, during this season, 

 several smaller swarms had come up from the 

 south, where, as apparently in all other parts of the 

 world, they are bred in the deserts. The poor cot- 

 tagers in vain attempted, by lighting fires, by shouts, 

 and by waving branches, to avert the attack. This 

 species of locust closely resembles, and perhaps is 

 identical with, the famous Gryllus migratorius of 

 the East. 



AVe crossed the Luxan, which is a river of con- 

 siderable size, though its course towards the sea- 

 coast is very imperfectly known : it is even doubt- 

 ful whether, in passing over the plains, it is not 

 evaporated and lost. We slept in the village of 

 Luxan, which is a small place surrounded by gar- 

 dens, and forms the most southern cultivated dis- 

 trict in the Province of Mendoza : it is five leagues 

 south of the capital. At night I experienced an 

 attack (for it deserves no less a name) of the Ben- 

 chuca, a species of Reduvius, the great black bug 

 of the Pampas. It is most disgusting to feel soft, 

 wingless insects, about an inch long, crawling over 

 one's body. Before sucking, they are quite thin, 

 but afterwards they become round and bloated 

 with blood, and in this state are easily crushed. 

 One which I caught at Iquique (for they are found 

 in Chile and Peru) was very empty. When placed 

 on a table, and though surroiinded by people, if a 

 finger was presented, the bold insect would imme- 



