Abstract:

Pomacea canaliculata  is a kind of aquatic gastropod mollusk that has come from other countries and is now commonly seen damaging rice production in South China. Jiangxi is one of the main provinces that have been invaded by the species. A survey was carried out using questionnaire over 11 prefecture-level cities in the province to investigate distribution of P. canaliculata  and damage it had caused. At the same time, a point sampling method was adopted to explore regularities of outbreaks of  P. canaliculata at various rice growing stages. Results show that (1) P. canaliculata were found in almost all corners of the province, displaying a declining trend from south to north in hazard, with Ganzhou and Ji′an being the two most severely infested areas; (2) P. canaliculata is very high in fecundity, laying 236.86 eggs per egg mass with hatching rate up to 90.80%; and (3) outbreak of P. canaliculata occurred at all growing stages of early, late and single-cropping rice, and its damage was more serious to rice at vegetative stages, like seedling and tillering stages. Damage of  P. canaliculata to rice was more serious in early rice fields than single-cropping and late rice fields. In early rice fields, the P. canaliculata community was composed mainly of baby snails, young snails and young grown-up snails, while in the single-crop and late rice fields, the community was dominated with grown-up snails. So, it is quite obvious that the seedling and tillering stages of rice are the critical periods for control of P. canaliculata. The findings in the research may serve as a theoretical reference for the study to reveal mechanism of the invasion and the control of P. canaliculata.

Key words: Pomacea canaliculata, damage, paddy field, fecundity, growth period