What kind of environment do you find these insects in,
Dytiscids mainly inhabit weedy ponds and lakes, but also streams and rivers.
what times of the year are they most active,
They spend the spring and summer as larvae, and are most active and available to trout during that period.
and do they eat midges?
Yes, as well as most other aquatic insects, small fish, and even their own.

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Taxon
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