Cook pasta according to package directions; rinse in cold water and drain.
Combine 1 cup yogurt and 2 tablespoons lime juice. Season with salt and pepper; set aside.
Whisk the remaining yogurt, lime juice, salsa and cilantro in a large bowl. Add pasta, black beans, corn and monterey jack; toss gently. Season with salt and pepper. Chill until serving.
Sprinkle with avocado and dollop with reserved yogurt mixture when serving.
*Blanched fresh, thawed frozen or drained corn from a can work well in this recipe. Top with sliced chicken to make it an entrée.