I thought all Annonas were pollinated by flies and beetles, not bees, part of the reason so many people have to hand-pollinate flowers for good fruit production. My cherimoyas are not old enough to have flowered yet, but I have native pawpaws in my yard. Their flowers are covered in small flies and beetles in early spring, such as right now. So I get excellent pollination and have never had to hand-pollinate my pawpaws.