Bob Wyatt calls the image that the fly presents to the trout its "prey-image". Borrowing the essential features of the Haystack and Usual, ComparaDun, and Klinkhamer Special the DHE is designed to present a strong prey-image. It incorporates a couple of primary stimuli, or 'triggers': a visible wing and a sunk abdomen. While suggesting natural aspects of the insect, these exaggerated features ensure that the fly will be noticed. The DHE is designed to represent that irresistible 'sitting duck' phase of the hatch.
The DHE is easy to tie, and more or less indestructible. To fish the DHE, touch only the wing and thorax with gel floatant. Keep floatant away from the abdomen, so it will be sure to sink

Hook: Dai-Riki 135 #14
Thread: 8/0 Brown
Wing: Medium to fine deer hair - coastal blacktail is a good choice
Abdomen: Olive/brown mix of seal and hare fur. Variants include seal's fur, stripped peacock quill, and herl
Thorax: Dubbed hare's mask. Use the spiky hair from front of face