My Year of Darwin 5/7/2014: Reduvids do Darwin

"At night I experienced an attack (for it deserves no less a name) of the Benchuca, a species of Reduvius, the 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 surrounded by people, if a finger was presented, the bold insect was immediately protrude its sucker, make a charge, and if allowed, draw blood."  Charles Darwin,Voyage of the Beagle

Darwin is traveling in Argentina and gets bitten by reduvid bugs, known to harbor Trypanosoma cruzi, the organism that causes Chagas Disease. The passage above goes on to describe one specimen that lasted 4 months(!) aboard the Beagle after having fed on a ship's officer. He describes the bite as painless. I have not been bit by any in South America (that I know of) but I was bit below the wrist in a local park in Pennsylvania and this was painful. 

 There is some debate if Darwin came down with Chagas and descriptions of his ailments, particularly his digestive issues, are consistent with Chagas (more details later). 

South American reduvid

Reduvid I found near my house (Fall 2013)