Summer Moon Lecture Series: Cone Noises
It’s 10 o’clock at night and I’ve just seen her fly into my bedroom; a flat, black body with some red spots along each side. I’ve looked around frantically for her but to no avail. She’s hiding somewhere waiting for me; sharpening her nose and licking her chops. Tonight, I know I’m prey; I’ll be scratching by midnight; there is a conenose kissing bug waiting for her next meal in my bedroom.
Conenose kissing bugs, assassin bugs, triatoma, are all names for the same night roaming, blood sucking creature that attacks us here during the month of June. Victims complain of various symptoms from itching, welts and 12-hour stupidity to full-on anaphylaxis. If we go to the internet or check out a documentary, we may get info on general triatoma, but not our special kind of triatoma. Our Chihuahuan Desert triatoma are different, but first let’s see about the other kinds:
Conenose kissing bugs range from the southern portions of the United States down into central South America (and have now been found in Australia, Asia and Africa). They live in old mud and adobe houses, the grassy roofs of tropical palapas, and decomposing wood piles, etc. Some triatoma are black and red and some are even mottled brown but all have a ¼ inch long proboscis (nose) and a voracious appetite for blood. They mostly feed at night and generally live with the vertebrates from which they feast, and some of those vertebrates be us. In some parts of the world, the conenoses will suck blood from humans every day.
Many carry in their gut the Chagas parasite (also known as Trypanosoma cruzi) which they can get from the blood of infected hosts and which they then pass along to their offspring. “The infection is spread to humans when an infected bug deposits feces on a person's skin, usually while the person is sleeping at night. The person often accidently rubs the feces into the bite wound, an open cut, the eyes, or mouth. Animals can become infected the same way, and they can also contract the disease by eating an infected bug.” Link to Changas Disease
Since it takes about 5 minutes for the Triatoma to have its meal, these healthy, moist bugs defecate while sucking. This is why the fecal material is deposited so close to the site of the wound. Once the creature leaves the scene of the crime the host starts to feel that funny tingly itch that happens as the numbing agent, injected by the predator, starts to wear off. This is when the hand begins to move involuntarily to the site of the incident and makes that earth shattering, life threatening mistake of sweeping across the wound and smearing the fecal material, with the Trypanosoma cruzi parasites, into the human host.
According to the CDC, of the 16 to 18 million people infected with T. cruzi, some 50,000 people die every year, and many don’t even know what ails them. The parasite, after a brief period of fever, becomes imperceptible in the body and eventually gathers around the heart, where, after 20 years, according to the New York Times Magazine, “…your heart explodes.” However, I have seen the feces of these bugs, and it is copious and nasty. I can’t imagine people not being able to find it on their sheets, much less their faces. Thank God our bugs don’t poop like that.
Here in the Big Bend our triatoma are different. About 15 years ago, Dr Almeida from UTEP, with his lovely graduate assistant, took blood samples from many of us in the Ghost Town and in the Park. They also collected as many conenose kissing bugs as they could on their brief stay. Two years later, they were back and took more blood tests and collected more dead conenoses. It seems that 25% of our conenose kissing bugs had Chagas, but that none of us did. There was not one person here who had contracted the disease even though we all are regular victims. What’s up?
Two things: first, our triatoma are desert triatoma; they are as dehydrated as we are. Look at them. They are flat, paper thin. We can’t defecate when we are dehydrated and neither can they. So our desert species do not defecate until about 9 to 10 minutes after they suck, once they are more hydrated. If they had Chagas, it wouldn’t matter; the vector is gone. Have you ever found nasty and copious bug poop anywhere near your face, sheets or bed? No, because it doesn’t happen here. If you catch one in a bottle, you’ll notice something that looks like a dried drop of ink; very different from what goes on in the tropics.
Secondly, these bugs have evolved here in the dry desert where all their self-protective human hosts have more sensitive skin. The minute we felt them we’d smash them, so they evolved to never stand on their host. Our conenoses stand on the bed, the sheet, etc., and whip their proboscis out and suck. Notice that when you have been bitten, it has always been on a body location that was against the mattress, or tied up in sheets, like your feet and toes. If the conenose were to defecate it would never be on us. Physiologically, entomologically physiologically, it can’t happen. So the drama is over: they are dehydrated and they do not stand on us. We are free of the threat of Chagas.
But there is one thing we do still need to keep in mind. Prof Almeida has not been able to get back to me about this, but I think I know why they come out in June. This has always been a niggling question for me.
Okay, so, conenose feast on rats and mice all year ‘round in the Big Bend and only come out during the month of June. When I see one in my bedroom and react like the New Yorker I can be, I can’t help smashing and squashing the bugs, but when I have my wits about me, I collect them in what I call The Coliseum and let them fight to the death. Sometimes I throw in a big, fat, healthy tick to give them a little sustenance but normally, by July, I have conenose eggs and eventually little noses hopping around inside the Coliseum as well.
This has lead me to deduce that the reason the triatoma leave a perfectly good host (the rat) for another in June (us) is because of competition. In June they are ready to lay eggs. If their eggs hatch in the nest with the rat, then eventually the rat will be killed by the increased number of little mouths to feed. If the adult triatoma fly off and deposit their eggs with a different host, that’d be us, then there is no competition, and they can feast for a while, lay their eggs in our houses and then either stay or go back to the regular nosh. Makes sense to me.
So, yep, she’s still here.
She’s waiting for me to turn the light off.
She may not threaten my life,
but she’ll surely make my life hell.
Some things to keep in mind:
They are attracted to lights at night; so turn yours off.
They hide well; if they see you looking, they will scoot under the table or around the post.
Kill them or they will lay eggs in your bedroom.