Excerpts from Jim Conrad's
Naturalist Newsletter

from the November 30, 2005 Newsletter written at Hacienda San Juan Lizarraga one kilometer east of Telchac Pueblo, Yucatán, MÉXICO
and issued from Hotel Reef Yucatan 13 kms to the north, MÉXICO

Katharine, who owns Hacienda San Juan, had mentioned that at the Social Services Building in town they'd hung up a poster showing the insect that transmits the dreaded Chagas Disease. The other day she pointed out a bug climbing a windo screen in the Big House and said that that might be the Chagas bug. Or maybe not. Hard to say.

It was a brown Hemiptera, a member of the "True Bug" Order, the kind of bug that as a kid in Kentucky I would have called a stinkbug without a second glance. I nudged the critter with a finger, smelled the finger, and it stunk like stinkbug.

The insect carried below its thorax a stiff, strawlike proboscis, however, and Katharine assured me that that proboscis could be used to puncture skin and suck blood, and that she'd squashed bugs just like these at the window and found them full of blood. Also, I remembered that some bugs in this order were called assassin bugs. I figured I'd better hike to town and look at that poster.

The poster showed a bug very similar to our window visitor, except that bright red spots marked its wing margins, which, happily, wasn't the case with our window bug. The poster gave only the insect's Spanish name, which was Chinche Hocicona, which translates more or less to Snouted Chinchbug. With that name and knowing that it was a vector for Chagas Disease, it was easy to Google up the rest of the story.

Our Chinche Hocicona's scientific name is TRIATOMA PALLIDIPENNIS or T. INFESTANS. The disease-causing organism it transfers from one victim to another is a flagellate protozoan called TRIPANOSOMA CRUZI. The disease organism is evolving into various strains, so symptoms for the disease vary from region to region.

Chagas Disease proceeds through three stages. The first stage begins the fourth or fifth day after being bitten and the main symptom is fever and a headache. The liver, spleen and heart begin enlarging. At this stage it's possible to cure the disease completely, but the symptoms are easy to misinterpret.

The second phase can last ten to thirty years, during which the walls of various body organs deteriorate.

In the last phase the central nervous system is affected, no cure is possible, and death may result.

Chagas Disease is bad in some places in Mexico but we're unclear as to how common it is around here.