Study on viability of the giant african snail in China

The giant African snail (Achatina fulica) is an important quaratine pest in the world. The experimental results obtained from 1989 to 1995 showed that its minimum and maximum lethal temperature and development threshold temperature were -0.2 degree C, 41.2 degree C, 12 degree C respectively, and its effective accumulated temperature was 2 422.6 day-degree. By using the overwintering or oversummering temperature limit, the law of effective accumulated temperature and method of bioclimate analogous distance, CSMVGAS (Computer System Model on Viability of Giant African Snail) was established for studying its viability in China. Using 30-year climate data of 698 meteoroligical stations all over the country, to perform CSMVGAS, the potential of giant African snail in China were divided into high viable region, viable region, low viable region and n on-viable region. The viable north limit was 28°±2°N. The viable area was about 15% of that in China. These results will be useful and helpful in making quarantine policy.