- Author: Kathy Keatley Garvey
Raymond Ryckman, emeritus professor of biochemistry and microbiology at Loma Linda University, San Bernardino County, gifted his collection, spanning more than half a century, to the Bohart Museum's growing global collection of nearly eight million specimens.
His donation includes 18 species of kissing bugs as well as 11 species of tsetse fly and other parasitic insects, said Lynn Kimsey, director of the Bohart Museum and professor of entomology at UC Davis.
“His collection is a tremendous addition to the Bohart Museum and we are honored that he thought of us to take care of it,” she said.
Kissing bugs, which feed on blood and transmit Chagas disease, are so named “because they often bite the thin skin around the lips and eyes of sleeping persons,” Kimsey said. In California, they're commonly found in the nests of wood rats and pack rats and in brush and woodpiles near homes. The insects are nocturnal. They invade residences, hiding in cracks and crevices by day and feeding on sleeping people at night.
Chagas disease, also known as American trypanosomiasis, is an inflammatory, infectious disease caused by the parasite, Trypanosoma cruzi, found in the feces of the kissing bugs, or triatomine (reduviid) bugs. According to the Centers for Disease Control and Prevention, the disease is found only in the Americas (mainly, in rural areas of Latin America where poverty is widespread).
Ryckman reared some of the parasitic insects from rotting cacti in Arizona and Mexico that comprised part of his thesis research. He authored more than 100 research papers and books, including a database on Chagas disease and its kissing bug vectors, assembling more than 23,000 references on the subject, Kimsey noted.
Ryckman also did research for Operation Whitecoat, operated by the U.S. Army Medical Research and Materiel Command at Fort Detrick, Maryland. He developed protocols for protecting troops and civilians from the disease. In 2007, he received a special Distinguished Achievement Award in 2007 from the Society of Vector Ecology. He has been a member of the Entomological Society of America since 1951.
Kimsey said kissing bugs are one of the most notorious insects belonging to the family Reduviidae. They feed exclusively on the blood of birds and mammals and “typically live in their hosts' nests,” she said.
Most of the species occur only in the Americas; and 12 are found in the United States. The most common species in California is Triatoma protracta, a large black or dark brown insect that occurs in the state's mountain ranges and in desert washes, where they live in rodent nests, Kimsey said. The insect is also known as the Western conenose, vinchuca, and Mexican bedbug.
“We tend to think of insect parasites like bedbugs and lice as being pretty small. However, kissing bugs are large, with the adults averaging about half-an-inch in length. They have a long narrow head and the mouthparts are modified into a long, apically pointed tube. At rest, this tube is folded up under the body.”
“The kissing bug's pharynx can generate suction pressures of 3-6 atmospheres. This makes the blood rush into the pharynx at the rate of 4 millimeters per second. You have to wonder what keeps the bug from exploding. However, they don't explode because a series of valves in their digestive track regulates the flow of blood. Some species excrete excess blood and digested materials during feeding.” They can create acute allergic reactions in humans. “Extreme allergic reactions occur more frequently from kissing bug bites than the bites of any other North American insects.”
Kimsey also pointed out that removing all brush and piles of debris away from homes in California is crucial for both fire protection and the elimination of rat nests.
“Pack rat nests are home to a diversity of insects and spiders besides kissing bugs,” she added. While doing research in the Algodones Dunes in Imperial County, “we found in a single pack rat's nest in a wash on the east side of dunes, Triatoma kissing bugs, black widow spiders, fleas, desert recluse spider and a diversity of beetles. I would not want to be a pack rat!”
Her comments appear in the summer 2014 edition of the Bohart newsletter.