[Effect of ground cage use on Oncomelania hupensis spread].

ABSTRACT

OBJECTIVE: To examine the effect of ground cage use on Oncomelania hupensis spread, so as to provide insights into precision snail control. METHODS: Twenty ground cages that were frequently used to capture rice field eels were purchased, including 11 packaging tape-made cages, 7 plastic cages and 2 nylon rope-made cages. The eel-capturing activity was mimicked, and 20 ground cages were assigned in settings with relatively high (1.00 snail/0.1 m2 and higher) and low snail densities (< 1.00 snail/0.1 m2) in Xindai Township, Pinghu City, Zhejiang Province during the period from 15 00 to 8 00 of the following day on April 13, 26 and 28. The numbers of snails carried by different types of ground cages were compared in settings with different types of snail densities using the rank-sum test. RESULTS: A total of 11 cage-times were assigned in settings with a high snail density, and a total of 77 snails were captured, with a mean number of 7 snails in each cage-time and 2.15 snails in 0.1 m2 ground cage. The mean numbers of snails carried by packaging tape-made and plastic cages were 2.47 snails/0.1 m2 cage and 0.37 snails/0.1 m2 cage, respectively. A total of 24 cage-times were assigned in settings with a low snail density, and a total of 8 snails were captured, with a mean number of 0.33 snails in each cage-time and 0.09 snails in 0.1 m2 ground cage. The mean numbers of snails carried by packaging tape-made cages were 0.12 snails/0.1 m2 cage; however, no snails were carried by plastic or nylon rope-made cages. The number of snails carried by ground cages was higher in settings with a high snail density than in settings with a low snail density (Z = -4.019, P < 0.01), and the number of snails carried by packaging tape-made cages was higher in settings with a high snail density than in settings with a low snail density (Z = -4.086, P < 0.01). No significant differences were found in the numbers of snails carried by different types of ground cages. CONCLUSIONS: The use of ground cage in snail habitats is a contributor to snail spread.