The Leaf-footed Bug comes by its name easily; the flattened area on its tibia looks like a bit of leaf (left, in the photo). This particular specimen was spotted on a corn leaf; the whitish dust on the leaf is corn pollen. The picture shows the bug larger than life-size, but it is a large bug; this one was a bit more than an inch in length.
One of the largest of the Desert Garden's piercing and sucking insects, it damages plants directly, and also indirectly through the bacteria introduced into the holes it makes. Notorious for damaging pecans and pomegranates, the Leaf-footed Bug is polyphagous, so if you, too, want to eat a lot of different fruits and vegetables, it's worth your while to eliminate this bug when you find it in the garden. Spraying insecticides to control them is unnecessary and a waste of money, so don't bother.
Of the three S's of basic insect control (squishing, swatting, and snipping), this one is definitely too big and too agile for any but snipping, to which the pictured specimen responded in the desired manner. Consider using long-handled scissors, as these guys are closely related to the stink bugs.