"We know it works in a shoe box-level experimental setting. Now we want to try it in a field setting," CRC director Tony Peacock told Reuters yesterday.

The CRC is applying to Australia's watchdog on transgenic applications, the Office of the Gene Technology Regulator, for permission to trial the herpes virus in sample populations of mice, in rodent-proof pens.

The disease can only be spread by mouse-to-mouse contact, after innoculation of rodents with gene-spliced material containing the modified virus.

Rigorous testing to prove the virus is "species specific" - which means that it cannot be transferred to other animals or humans - will be required before expected full release in three years.

The main beneficiary of the virus would be Australian farmers, who grow one of the world's biggest grain export crops.

Australia's mouse population explodes into uncountable billions every four years or so, usually at the end of a drought such as one now lingering after decimating 2002/03 crops.

Peacock says a bad mouse plague can cost over A$150 million ($90 million) in lost crops, while a moderate plague would cost A$50 million.

The cost is also social.

"If you meet people who have lived through a mouse plague, they physically shudder. It's not a pleasant thing to put your kids to bed at night and shake out the bed clothes to get the few mice out," Peacock said. "It's really revolting."

The genetically modified mouse herpes virus is in a tradition of Australian leadership in biological pest control.

The use of myxomatosis disease fifty years ago and calici virus 10 years ago to control multiplying rabbit populations delivered tens of billions of dollars worth of benefits, Peacock said. He estimates calici alone was worth A$6 billion for agricultural industries.