image credit: Raid
Tying Terrestrials:
Beetles
If it is July, August or September and I am on the Henry's Fork or most Western streams, and if I could only have one fly...it would be a #14-16 black beetle.
image credit: The Essential Fly
Ants:
From late spring through the first freeze in the fall, an ant pattern is one of the really great "change up" flies anywhere. When they just will not eat a mayfly...
Do not forget that there are also flying ants, red ants and flying red ants...just as important. #14-16.
Videos on Tying Ants:
The Ant: Simple Entomology for the Fly Tyer and Fly Fisherman - Rog and Jane Klettke
Simple Black Ant Fly - terrestrial fly pattern - by McFly Angler
image credit: Fish4Flies.com
Grasshoppers
On windy hot days, it is a hard to beat a grasshopper pattern when fished close to the bank. If the hoppers are flying, cover all the water...

image credit: science4fun.org
Tying the GFA (General Foam Attractor) Grasshopper by tightlinevideo
Videos on Tying Grasshoppers:
The Grasshopper: Simple Entomology for the Fly Tyer and Fly Fisherman - Rog and Jane Klettke
Tying midges: midges include both aquatic and terrestrials. Most fly fishers
use the term "midge" to describe any very small fly like insects.
Midges I: Simple Entomology for the Fly Tyer and Fly Fisherman - Rog and Jane Klettke
Midges II: Simple Entomology for the Fly Tyer and Fly Fisherman - Rog and Jane Klettke