Makes about 4 cups
Combine the crabmeat, celery, scallions, parsley, carrot, and grapes in a large bowl.
Whisk together the mayonnaise, yogurt, lemon juice, orange juice, salt, pepper, and hot pepper sauce (if desired), in a small bowl.
Fold the dressing into the crabmeat salad and toss gently to coat. Taste to correct seasonings. Refrigerate, covered, to chill.
Line the pitas with the endive and fill with the crabmeat salad.