Create category

function insert_category ($category,$description,$parent) {
$parent_term = term_exists($parent,'media_category');
$parent_term_id = $parent_term['term_id'];
wp_insert_term(
    $category,
    'media_category',
    array(
        'description' => $description,
        'slug'        => $category,
        'parent'      => $parent_term_id,
    )
);
}