The Latin American insects are named after their habit of night time feeding on the face of the victim, often spreading the deadly Chagas disease.
Biologists have for the first time discovered that the insect also feeds on plants.
Dr Rod Dillon from Biomedical and Life Sciences had the idea while he was eating tomatoes for lunch.
“I wondered if bloodsucking sandflies in my lab would feed on tomatoes because they are known to like plants.”
He discussed his idea with co-researcher Dr Fernando Genta in Brazil, who extended the idea to kissing bugs.
For over a hundred years, the scientific literature has accepted that these insects feed exclusively on blood.
However, this research shows that they also consume sugar and nutrients from fruits.
One of the most important outcomes was the reduction in the bugs’ mortality after ingestion of blood, which dropped from 40% to about 20%.
Dr Dillon said: “This means they are healthier as they have more energy, can live longer and bite more people.”
Insects which consumed tomatoes showed greater weight gain after the blood supply, indicating an increase in the volume of blood ingested.
Dr Genta said: “The discovery adds a new element to kissing bugs life cycle and will impact knowledge of the transmission of Chagas disease and the control strategies for this disease."
The research led by Fernando Genta and Hector Diaz at the Instituto Oswaldo Cruz (IOC) in Rio, Brazil included Rod Dillon of Lancaster University as well as participants from the Laboratories of Molecular Biology of Insects; Epidemiology and Molecular Systematics; and Ecoepidemiology of Chagas disease at Oswaldo Cruz Institute. Brazil’s Federal Fluminense University (UFF), the National Institute of Science and Technology for Molecular Entomology and the University of Liverpool also contributed to the work.