Tim Flagler of Tightline Productions posted this great video with a sample of he bugs found in the South Branch of the Raritan.
First appearing is a willow nymph, or early black stone fly nymph. The early black stone is makes it's first appearance in February and March when temperatures start to rise in the late afternoon. This hatch offers some great winter dry fly fishing, but don't forget the nymphs which are in the stream all year.
Next is the Isonychia bicolor, also called Iso, Slate Drake, or Lead Wing. Found in fast moving riffles in highly oxygenated water, these nymphs are fast swimmers that dart along the stream bottom. These mayflies start emerging in midsummer and hatch in to the fall.
Followed by one of my favorite bugs the scud because they are very abundant an in the streams year round. Tim's video show how prominent the orange is in the natural.
Then there are two may fly nymphs one from the genus Ephemerella (Sulpher) and the other from the genus Maccaffertium (March Brown or Cahill).
Trichoptera (Caddisflies) are next on the scene with Hydropsyche, which is a free living net builder, which are important because they get dislodged from time-to-time and drift down stream during times of behavioral drift.
Finally a Gastropoda or snail which float and crawl most of our streams.
The one bug I did not mention was the Water Penny, which is a beetle larva that the Sulpher nymph was riding. I don't know the type of beetle it becomes, but a cress bug imitation should represent this bug quite well.
Tim's South Branch Sampler 1/17/14 is a wonderful sample to the food available to trout in our streams in New Jersey and a great reference to use when designing fly patterns.
I recommend you check out Tim's other videos at Tightline Productions on Vimeo.