These are generally found on the shoals or the shoal drop-offs into deeper water. When not feeding they tend to hide under submerged logs and rocks or among the bottom vegetation. They usually prefer pollution free water that is well oxygenated but certain species will live in the more stagnant ponds. Dragonflies are the fourth most important source of food for trout in the Interior lakes. For dragonflies I haven't found a significant difference between feeding samples of those fish caught during the day to those caught in the evening or darkness hours.
Dragonflies are good at hiding and staying out of reach from the feeding trout.
If it can find a dragonfly, the trout will often take it in preference to many other available foods. Likely this is because of the its large size. One dragonfly nymph ready to hatch is equivalent to about 25 Chironomid pupa. The main hatches of the dragonfly from nymph into adult peaks about mid July with lesser hatches both before and after that time. This 'hatching' migration and often the hatching itself often occurs in the evening or at night.