Assessment of the socio‐economic impacts associated with the arrival of apple snail (Pomacea canaliculata) in Mwea irrigation scheme, Kenya

Abstract

BackgroundIn Kenya, rice (Oryza sativa L.) is mainly produced under irrigation by small‐scale farmers. Mwea irrigation scheme (MIS) in Kirinyaga County accounts for 80–88% of rice production. Here, rice is the main source of livelihood and a source of revenue generation for the county. However, a recently established invasive freshwater snail, Pomacea canaliculata (Lamarck) (family: Ampullariidae), a species of apple snail, presents a serious threat to rice production.ResultsHousehold surveys, focus group discussions and key informant interviews highlight apple snail as a serious problem in MIS. Households that observed at least a moderate level of infestation (>20% of cultivated area) experienced significant reductions in rice yield (~14%) and net rice income (~60%). Farmers reported increased use of chemical pesticides for management of apple snail. In addition, the cost of hired labor for physical removal of egg masses and snails is resulting in substantial negative effects on net income. Farmer age, area of land owned, responsibility for decision‐making, receipt of extension advice, training, and membership of a farmer organization, were all statistically significant variables to explain farmers awareness of the need for area‐wide apple snail management.ConclusionStrategies to limit the spread of apple snail are urgently needed. A Multi‐Institutional Technical Team (MITT) has been established to spearhead management efforts and consolidate advice to farmers on how to manage apple snail. However, without action to mitigate spread, the consequences could be disastrous for rice production and food security in Kenya, and for other rice growing regions across Africa. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Efficacy of Giant River Prawn Macrobrachium rosenbergii in Controlling the Invasive Snail Pomacea canaliculata: Implications for Ecological Farming

“…Currently, bio-control of various ampullariid species has employed the common shelducks Tadorna tadorna [24,25], Chinese soft-shelled turtle Pelodiscus sinensis [22], common carp Cyprinus carpio [26], and black carp Mylopharyngodon piceus [26], with relatively good control effects. Nevertheless, the life cycle of P. canaliculate consists of three stages: eggs, juveniles, and adults, with a total lifespan of 2-5 years [27]; with high egg-production rates, one female snail can reproduce up to 300,000 juveniles annually, and the juveniles can reach sexual maturity within 3-4 months, leading to overlapping generations [28]. Most existing biological control research on these snails has focused on the clearance and control of adults while neglecting their extremely strong reproductive ability, which results in rapid population recovery [21,22,24,25,29].…”