Environmental activist Jack Ehrhardt must stay ever alert against a silent enemy that sucks the blood of its victims while they sleep.
While most people have a small welt after the Triatoma rubida has snacked on their blood, Ehrhardt is one of hundreds of people who suffer a life-threatening allergic reaction after being "bitten" by the insect that sucks the blood of humans or animals.
"My wife found me lying on the floor in the middle of the night," Ehrhardt said, of the first time he was "bitten", four years ago.
"I had gone into shock."
No bigger than a man's thumbnail, the dark brown Triatoma rubida goes by many names depending on the region in which it is found, including the Walapai tiger, conenose kissing bug, Mexican bedbug and the assassin bug.
There are four species of conenose bugs in Arizona, although other species exist throughout the Southwest.
The Triatoma protracta species is most commonly found in California.
The Triatoma, which makes its homes in rats' nests during the winter, has bitten Ehrhardt six times, sending him into anaphylactic shock each time.
He now carries a vile of adrenaline and a syringe so that he can give himself an adrenaline shot if need be.
"It slows down the reaction until I get to a hospital," he said.
Ehrhardt, who lived in the Cerbat Mountains until about three months ago, is constantly on the lookout for the assassin bug because with each bite the reaction is more severe.
He moved out of his home in the Cerbats where the assassin bug is more prevalent, he said, even though he knows it can be found almost anywhere in Arizona.
The feeding bite of the bug, which usually occurs on those areas of the body not covered by close fitting clothes, is painless because its saliva contains an anesthetic.
The Triatoma does not inject poison, but after injecting its razor-sharp proboscis, the tubular feeding structure, it sucks the blood of its victim, most often while the person is sleeping or resting, according to Rob Grumbles of the University of Arizona Cooperative Extension .
Grumbles, his wife and his son have all been bitten by the assassin bug.
"My wife and I get a welt, but my son is really allergic to it, and starts going into shock," Grumbles said.
"His skin and throat swells up and he gets nauseous."
The insect will draw blood for up to 20 minutes, although the allergic reaction in people sensitive to the protein in the saliva can be felt within minutes, Dr.
Neil Marshall said.
Marshall developed an antigen for patients allergic to the bug back in the early 1980s while pursuing a doctorate at UCLA.
The ammuno therapy treatments, which make patients less allergic to the bug's bite, were administered by 10 Kaiser Permanente medical facilities and 20 allergists in California before the federal Food and Drug Administration got wind of the grass-roots operation in 1999 and stopped the professor from distributing the antigen.
"It is incredible the number of people in Arizona and Southern California who are allergic to the Triatoma," Marshall said from his office at the College of Notre Dame near San Francisco, where he teaches environmental biology and physical geology.
"There are people alive today because of what I did and I would like to continue doing that," he said.
"People have died as a result of these bugs, and there is no telling how many deaths go undiagnosed or are listed as a heart attack."
However, Marshall must first make the FDA happy by proving to them that the drug is safe, even though people have been using the therapy for years.
Shirley Milligan is one of those people.
"I was getting my antigen therapy from Kaiser Permanente and it was really helping," said Milligan, who lives in Oak Glen, Calif.
"But it is no longer available at Kaiser.
I haven't been able to get it anywhere for about a year.
I am terrified the affects of the therapy will wear off soon."
However, Marshall, who makes the antigen by extracting saliva from the glands of the kissing bugs, is still looking for an FDA-approved lab that will package and distribute the drug for injection.
"The lab will be the intermediary between me and the allergist," he said.
"But I am having trouble finding a lab because it is an orphan drug.
It won't make a lot of money."
Jacob Pinnas, an allergist at the Arizona Health Sciences Center in Phoenix, was also studying the affects of Triatoma saliva on humans and attempting to develop methods for desensitizing those allergic to the bite.
He no longer works on the project, however.
"It was very affective," he said of the antigen," but I'm not doing it anymore.
I wasn't able to keep my colony (of bugs) alive, and I wasn't getting reimbursement."
Marshall said he will continue to work on the project.
"There is so much interest in it," he said.
"I am still actively involved in getting FDA approval.
There are a lot of people that need it."
Meanwhile, Ehrhardt and other Kingman residents say they are always on the lookout for the bug that is attracted to light and flies or crawls into people's homes at night in search of a blood meal.