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January 14, 2016

Kissing Bugs Are Not As Friendly As They Make Out

Tim Gibb, Insect Diagnostician, Department of Entomology, Purdue University
Larry Caplan, Extension Horticulture Educator, Vanderburgh County, IN

Recently the media (print, broadcast, and social) lit up with the news that “kissing bugs” were loose in the US, and are spreading a horrific tropical disease called ‘Chagas disease’.  As most sensational news stories turn out, the panic being caused is overblown, and the actual risk here in Indiana or in the Mid-west is practically non-existent.  Nevertheless, since that time we have received telephone queries and physical samples at the Plant and Pest Diagnostic Laboratory asking for identification and verification.  In every case, these sightings and samples have turned out to be common household insects that, though they bear a slight resemblance to the kissing bug, are completely harmless.

Two insects that are common in Indiana – especially during the fall time – and can look like the kissing bug are Common leaf-footed bug (Fig 1) and Boxelder bug (Fig 2).  They enter and reside in homes throughout the winter months and so may be especially easy to confuse with the very rare ‘kissing bug’ described in by the media.  Both may be a nuisance but neither bite nor harm people.  In any case, the kissing bug story is valuable in that it promotes awareness and vigilance when it comes to insects inside our homes.

By contrast, the kissing bug (Fig 3) is one of several species of triatomine bugs, almost all of which are from the genus Triatoma.  These insects have always been in the US, found mostly found in the southern half of the US, but Indiana and Illinois are within their habitat range.  Other names for this insect are cone-nosed bug, or bloodsucking conenose.  These belong to the assassin bug family and are usually considered beneficial insects, because they attack other pest insects.  Triatomine bugs are unique because they feed on the blood of mammals (including humans), birds, and reptiles.

The kissing bug is nocturnal, coming out to feed at night, so it’s not common to actually see the insect.  By day, they can be found in brush piles, under tree bark, or under rocks.  Outdoor pet kennels and rodent dens are also common hiding places. They have a flattened abdomen with orange-red to yellowish horizontal markings, and are about one-half inch long (Fig 4).
 The adults are attracted to outdoor lights during the summer and early fall. 

A very small number of these triatomine bugs carry a parasite, called Trypanosoma cruzi, which causes Chagas disease. The initial symptoms often go unnoticed because they are usually mild, and can have many causes. Symptoms include fever, fatigue, body aches, headache, rash, loss of appetite, diarrhea, and vomiting.  Swelling at the bite site is also common.  These symptoms usually disappear within a few weeks or months, but the parasites may remain for decades or even for life.  The disease may progress to cardiac (heart disease) or intestinal problems if the disease is untreated.

It’s actually not easy to catch Chagas disease.  The parasite that causes the disease is in the bug feces. The bug generally defecates on or near a person while it is feeding on their blood, generally when the person is sleeping. The parasite can enter the body if the fecal material gets rubbed into the bite wound or into a mucous membrane (the eye or mouth).

The symptoms and spread of the disease sound horrific but remember that Chagas is most common in rural areas of Latin America; only rare and isolated cases have been found in the US. 

Because most indoor structures in the United States are built with plastered walls and entryways are sealed to prevent insect invasion, triatomine bugs rarely infest indoor areas of houses.

Again, this insect is present, but not common, in our area. Even if one was found, it’s not likely to carry the parasite; let alone re-infect a person.

For more information, visit the CDC website athttp://www.cdc.gov/parasites/chagas/.

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Click image to enlarge

 
​​​Fig. 1: Common leaf-footed bug
​Fig.2: Boxelder bug
 
​Fig. 3: