For fly fishermen one of the first olives to appear on the river in springtime is the Large Dark Olive or Baetis rhodani. Imitation can be made from a variety of trout fly patterns for the nymph, dun and spinner. Hatches may occur any time through the season. The flies are generally smaller and paler in the height of the summertime. Typically Baetis Rhodani, commonly known as Large Dark Olives or LDO's hatch in March through to April and again in September to October in the UK
