Target: Head eating mice

Grant Singleton checks a live capture mouse trap during a population study of mice in wheat crops.

Biological mouse control program

Wayne Saal of 'Waco', 60 km west of Toowoomba, is one of many farmers who can tell you about the damage being done by mice which are appearing across cereal crop lands in plague proportions. And about the difficulties of managing this four-legged onslaught.

"The mice did tremendous damage to our sorghum this year. It is amazing how they can damage every head," said Mr Saal who crops 1200 hectares with sorghum, corn and cotton in summer, wheat, barley and chickpeas in winter.

"They will go for the tastier variety and the tastier bit of the plant. They run up the stalk and chew out the nodes, which kills the head and ensures that it will not produce grain.

"Some of us are getting to the stage where it is hardly worth-while growing a crop — the mice just mow it down again."

Mr Saal said that management is easier said than done. "We have tried earlier harvesting and grain drying. We have sprayed ROUND-UP on sorghum to kill it 3-4 weeks before harvest and then dried the grain.

We have to explore all management devices and it is very difficult to strike a balance between caring for the environment and protecting our crops."

Biological control offers hope

Mr Saal and other growers provide locations for traps and radio tracking of mice in a biological control research project headed by Grant Singleton of CSIRO Wildlife and Ecology.

Dr Singleton's work in Queensland is targeted at the mice feeding on grain in the field.

City parasite to country mouse

After careful evaluation, the researchers released a roundworm parasite of mice on three properties on the Darling Downs in May 1992.

The parasite already exists in populations in the cities and researchers say it has reduced the production of young under laboratory conditions. Dr Singleton's team has been engaged in translocating the parasite to cereal growing areas.

Dr Singleton said that while the May release was not a great success, probably because mouse population densities were not high at that time, there was another release in February this year when mouse densities were higher and a further release in June.

He said the parasite flourishes in the burrows in moist conditions. That the mice didn't pick it up was probably partly due to the dry and drought.

Dr Singleton said the work is aimed at controlling plagues, not eradication. The idea is to keep numbers within economic limits.

"These releases will help to establish a threshold density for introduction of the parasite. Where the parasite persisted it did appear to reduce the mouse population."

CONTACT: Dr Gram Singletion 242 1658

Region North, South, West, National