Is there hope for sustainable management of golden apple snails, a major invasive pest in irrigated rice?

The golden apple snail or GAS (Pomacea canaliculata) is an important invasive pest in irrigated rice that feeds on young rice plants. In many countries in SE-Asia, governments have recently decreased their support of training courses for snail management, because farmers are now considered to know how to effectively manage this pest. Although a great number of sustainable control methods is recommended which do not involve the use of pesticides, it is uncertain whether these are taken up by farmers. Probably, the easiest way to control GAS, is the application of synthetic 'instant kill' molluscicides, which can have detrimental effects on the environment, non-target species, and health. The aim of this study was to develop ideas for solutions on how to achieve a sustainable management of GAS without or at least a decreased use of molluscicides. In a large-scale approach, we conducted interviews with rice farmers in seven regions across Vietnam and the Philippines, assessing the participation in training courses, knowledge on snail ecology, the methods of controlling and the utilization of the snail, and the farmers' suggestions on how to improve pest snail control. Only 23% of the farmers had previously received training in GAS management. We found that training neither had positive nor negative effects on the number of sustainable methods applied, molluscicide avoidance, concern about using molluscicides, or on the farmers' knowledge about GAS. As much as 74% of the respondents applied molluscicides. Contrary to recommendations, farmers applied only few sustainable control methods. All farmers had clear knowledge gaps about GAS, especially in species identification, which can even further the ongoing decline of native mollusks in rice landscapes. We conclude that the decision to phase out information campaigns has been taken to rash, and that trainings in our study regions carried through previously had limited success, and thus need revision. To decrease molluscicide use, and to promote sustainable management on the large scale, we synthesized our results, and we suggest that information for farmers might be provided through media often accessed, such as TV, radio or the internet (e.g. by entertainment education). We further discuss the potential of community cooperation to achieve sustainability. As there are distinct limitations to these approaches, we have developed the concept of local GAS management and utilization companies (GASMUC) which could take over sustainable control and utilization of GAS, and native mollusk conservation for an entire community. (C) 2016 Royal Netherlands Society for Agricultural Sciences. Published by Elsevier B.V. All rights reserved.