Freshwater Shrimps are readily available trout food throughout the season. Most of the lakes and still waters have an abundant freshwater shrimp population living in the shallow areas of a lake in amongst the bottom vegetation.
Czech / Polish nymphs fly patterns are tied to imitate caddis larvae and gammarus. Hence, they are in a wide range of colours; including green, brown and grey. The Czech fishing method requires the flies that will sink quickly which is why the patterns are heavy and slim.