On an August morning last year, an American couple soon to embark on a European river cruise awoke in a luxury hotel in Lisbon.
Staring back at them from the headboard was a bloodsucking insect.
It wasn't a mosquito. It wasn't a bedbug.
The couple captured the bug in a tissue. Suddenly, bright red blood oozed out, a sign that the insect had fed recently.
They wondered: Could it have bitten them while they slept?
Their alarm only grew when one of them noticed a dark brown streak on their arm and finger. The insect's feces, perhaps?
They'd later learn the culprit was an adult female kissing bug.
More than half of all kissing bugs travel with an accomplice—a parasite called Trypanosoma cruzi. The parasite causes Chagas disease, which can lead to serious heart problems. T. cruzi is transmitted through the insect's feces rather than its bite.
But how did this particular species of kissing bug, native to the dry, desert-like climate of the southwestern U.S. and northwestern Mexico, get to Portugal?
That question became the centerpiece of a scientific investigation led by UD assistant professor and medical entomologist Jennifer K. Peterson and her team of Blue Hen sleuths. Students in her fall 2025 Medical Entomology (ENWC 410/610) class donned their detective hats and helped investigate what appears to be the first documented live kissing bug in Europe.
This is the Hospesneotomae protracta kissing bug specimen that was found by a couple staying in a Lisbon hotel room. Credit: Kathy F. Atkinson, Jennifer K. Peterson