BLACKSBURG, Va. — Most folks think of cockroaches as pests, but not researcher Mary Ross.
She sees the hundreds of thousands of them in her laboratory as the perfect guinea pigs: easy to reproduce, easy to feed, easy to house and not the sort of beast that animal lovers go out of their way to shield from the perils of laboratory work.
"I don't mind working with a German cockroach," Ross said in an interview at her Virginia Tech lab stacked high with containers of wiggling roaches. "When you keep it in a jar and keep it clean, it's not bad--a lot better than flies."
Ross, a professor of entomology, has studied the German cockroach, the most common roach, for nearly 30 years in the same laboratory.
She boasts the world's largest collection of mutant roaches--about 60 different types that can be detected by the naked eye of someone well versed in the anatomy of normal roaches. Laboratory equipment must be used to observe the more subtle mutations of others.
Some mutants feature different eye colors: green, purple dark red, "a very pretty color of pink" and a striped pink. Others have different skin colors or unusual bubbles on their skins.
'Easy to Rear'
"They're very easy to rear," Ross said. "That's the thing that makes them an excellent laboratory animal."
A female can carry up to 40 nymphs in its tiny egg case. About all Ross' roaches need is a bit of screen to climb on in their jars. Their diet: dry nuggets of dog food.
Ross said she doesn't face opposition from animal rights activists who protest the use of dogs and other animals in experiments.
"Nobody seems to object if we kill off a few cockroaches," she said. "They're not protected that way, so they have to protect themselves."
And they seem to be doing well, thank you.
They've moved along with people around the world, into areas where they couldn't survive in nature, such as Alaska. More and more of them are able to withstand pesticides as well, as research from Ross' lab has helped document.
Some of her work focuses on the genetics and behavior of roaches. She also recently acquired some Asian cockroaches, which must be locked up because authorities don't want them to spread out from the Florida area.
"The big thing is they fly," Ross said. "The adults fly inside and gather on TV sets and whatnot."
Although roaches are considered a nuisance by the millions of people who contend with them at home, most roaches live in the wilderness and are no problem, Ross said.
Out of 3,000 to 4,000 kinds of roaches that can be found, "no more than 23 are worldwide pests," she said.
But keeping thousands of them on hand for research has its drawbacks.
Ross and her colleagues have set traps to try to keep stray roaches in the lab. Some of the roach jars are greased with petroleum jelly so roaches who climb to the top slide back down.
But a few have gotten out, to the dismay of other tenants of the building.
Another worry is the possibility that an exterminator could accidentally wipe out Ross' life work. A sign outside the lab says: "Please do not spray insecticide in this lab. Thank you."
The one other problem seems to be that roaches multiply and fill up Ross' hundreds of jars faster than she has a use for them. The solution: shake the excess roaches out of the jars from time to time.
"We put acetone on them," Ross said. "And one of my colleagues takes the dead cockroaches home and uses them as fertilizer."