Biological control of the exotic invasive snail Pomacea canaliculata with the indigenous medicinal leech Whitmania pigra

ABSTRACT

The apple snail Pomacea canaliculata has been an invasive species in China for decades and causes enormous losses to agriculture. The predation capability of the leech Whitmania pigra on P. canaliculata was studied for its economic benefit and potential application. In the present study, the leech W. pigra exhibited a strong predatory capacity in controlling P. canaliculata under both laboratory and field conditions, and it showed no bias towards consuming smaller snails during the experiments. More than 80% of the 80 snails (of which half had reached maturity) were preyed upon by 20 developing leeches (2–7 g) in miniature rice fields over a 15-day period, and the number of rice seedlings damaged by P. canaliculata was decreased in the presence of W. pigra. In a separate experiment, 15 developing snails were exposed to caged leeches and conspecific snails for four weeks. The food intake and growth of P. canaliculata were inhibited under the predation risk imposed by W. pigra, but the feeding rate, food conversion efficiency and survival of P. canaliculata were not conspicuously influenced.

KEYWORDS:

• Predatory potential
• apple snail
• paddy field
• natural enemy
• predation risk

Acknowledgements

The authors thank Dr. Pablo R. Martín for his assistance with the statistical analysis.

Disclosure statement

No potential conflict of interest was reported by the authors.

Geolocation information

Guangzhou City, China (23°17′ N, 113°37′ E).

Additional information

Funding

This work was financially supported by grants from the National Natural Science Foundation of China (No. U1131006, No. 30770403 and No. 30900187), Science and Technology Planning Project of Guangdong Province (No. 2015B090903077) and the Overseas Joint Doctoral Training Program of South China Agricultural University (2017LHPY017).