In this case the fluke eggs are passed in the late summmer, which then infect the snails. Environmental conditions play a vital role in the success of the fluke development. Temperatures below 10 degrees will see the development being haltered, and the flukes will remain trapped in the hibernating snails throughout the winter. Development will then resume when temperatures rise above 10 degrees. The cercariae are then shed from July, and disease may be seen from August onwards.
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→ infect snails
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→ development halted when temperature <10°C (i.e. flukes trapped in hibernating snails through the winter)