I got my mangoes infected with mealybugs few weeks back and successfully repelled them using neem oil (neem extraction). First I applied neem oil every 4 days for about two weeks and noticed that spreading had stopped. But there were few white patches in fruit stalks here and there.
I continued to spray same neem oil extraction on mango tree every 5 days till now and saw how successfull it was. Now fruits are being ripe and I started harvesting them. So this another success story of using neem oil for mealybugs.