Darwin’s Bloody Bug Night

It was the night of the 26/27th of March, 1835, while in Chile, that Darwin noted his infamous run-in with the Benchuca, possibly the Vinchuca Bug, Triatoma infestans or Rhodnius prolixus).

From the Voyage of the Beagle:

We crossed the Luxan, which is a river of considerable size, though its course towards the sea-coast is very imperfectly known: it is even doubtful 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 gardens, and forms the most southern cultivated district 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 Benchuca, 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 surrounded by people, if a finger was presented, the bold insect would immediately protrude its sucker, make a charge, and if allowed, draw blood. No pain was caused by the wound. It was curious to watch its body during the act of sucking, as in less than ten minutes it changed from being as flat as a wafer to a globular form. This one feast, for which the benchuca was indebted to one of the officers, kept it fat during four whole months; but, after the first fortnight, it was quite ready to have another suck.

This event has triggered much conjecture on whether this could possibly have been the source of Darwin’s illness later in life, because the Vinchuca is the vector of the protozoan parasite Trypanosoma cruzi which causes Chagas’ disease.

(Image of Rhodnius prolixus nymphs and adult by Thierry Heger, as found on Wikimedia Commons. The quote is from Project Gutenberg’s A Naturalist’s Voyage Round the World, by Charles Darwin)


3 Comments to “Darwin’s Bloody Bug Night”

  1. Fascinating! I can imagine the curiosity that would lead to a person sitting watching a bug feeding on his finger; I did a bit of experimenting with mosquitos when I was a kid. Did you know, that once the sucking tube is inserted into the skin, if you pull the skin taut, the mosquito can’t escape?The risks we took in the pursuit of knowledge! All unaware, of course.Now we take similar risks in pursuit of money. Very foolish.

  2. I have arrived as a visitor to your site seemingly by accident. This story reminds me that there are no accidents! Viva Benchuca. Greetings from “Slug’s Rest” on the beautiful Oregon Coast near Newport (I hope we don’t have those here, although our mosquitoes could give a Benchuca a run for the money) Warmest regards, “Mrs. Slug”

  3. In a foreward to Ralph Colp, Jr’s “Darwin’s Illness” (2008), historian James Moore writes that Darwin’s illness can be attributed, “to arrested Chagas’ [disease] plus fluctuating mental pressures from his taxing work on evolution and other personal stresses” (x). This is Colp’s conclusion in the book which summarizes more than 15 different theories regarding Darwin’s illness.


Get every new post delivered to your Inbox.

Join 555 other followers

%d bloggers like this: