Possible Clues:

• Welshman, an inverted nymph
• Knight getting help, bringing in a nymph
• Diana metamorphosed into a nymph
• Greek mythological water nymph
• Young dragonfly
• Larva's fine, and moving around
• River nymph is to catch boy avoiding lakes
• Nymph appears in a new advertisement
• Aquatic larva reported near boundaries of airfield
• The sort of nymph Diana might become