Upper Delaware river insects, insect identification for fly fishing caddisflies.

Order Trichoptera - Caddisflies

Select a Caddisfly from the drop down menu below.

   Caddisflies are by far the largest group of aquatic insects, with estimates of nearly 50,000 species world wide, with well over 12,000 species in North America. Caddis are also by far the most complex, with each genus widely varying in type of case, and pupation habits. Some build portable cases, and abandon them, building new ones as they grow, others build fixed cases, others are free living, and don't build cases until their final instar. Cases are constructed from various materials, and are constructed, and attached to the substrate by means of spinning silk thread. Cases differ greatly, to the point of some species building cases from different materials at different larval growth stages. Most caddis hatches are thickest during warm sunny days, the sun triggers the hatch by creating a greenhouse like effect through the water, warming the larval case.

   Most species have a univoltine life cycle, very few have multiple broods during the same season. Caddis adults live for a few days to a couple of months after mating, and egg laying flights. Others like Frenesia emerge late in the season, (November - December) and live in the adult stage throughout the winter, with mating, and egg laying flights taking place the next spring. Adult Caddisflies find sustenance in the form of pollen, and plant matter.

   Caddisflies inhabit a wide range of environments, with some species being much more tolerant of pollution than are Mayflies, and Stoneflies.

Upper Delaware River float trips

Jerry Hadden's Guide Service

Fly fishing float trips for wild trout on the Upper Delaware River.


Delaware River fly fishing with Jerry Hadden.