Ch. XVII.] HORSE-FLIES AXD WASPS. 313 



now passed over without even a cloud to relieve the deep 

 blue of the sky or temper the rays of the sun. 



The vegetation on the plains was almost entirely com- 

 posed of thorny plants and shrubs ; acacias, cacti, and 

 bromelia3 were the most abundant. Animal life was 

 scarce ; there were a few flycatchers amongst the birds, 

 and armadillos were the only mammals. Horse-flies 

 (Tdbanus) were too numerous, and drops of blood trickled 

 down our mules' faces where they had feasted. In some 

 parts large, banded black and yellow Avasps (Monedula 

 surmamemis, Fabr.) came flying round us and had a 

 threatening look as they hovered before our faces, but 

 they were old acquaintances of mine in Brazil, and I knew 

 that they were only searching about for the horse-flies 

 with which they store their nests, just as other wasps do 

 with spiders, first benumbing them with their sting. I 

 noted here another instance of the instinctive dread that 

 insects have of their natural enemies. The horse-flies 



were so blood-thirsty that we could kill them with the 



f 



greatest ease with our hands on the mules' necks, or if 

 we drove them away they would return immediately. 

 As soon however as a wasp came hawking round, 

 the flies lost their sluggish apathy and disappeared 

 amongst the bushes, and I do not think that excepting 

 when gorged with blood they would easily fall a prey to 

 their pursuers. 



We were joined on the road by a storekeeper on his 

 way to Teustepe. He was armed with pistols, which it 

 is the fashion to carry in Nicaragua, though many 

 travellers have nothing more formidable in their holsters 

 than a spirit flask and some biscuits. He talked as usual 

 of threatened revolutionary risings, but these form 



