Dragon fruit got worm?

I love to eat dragon fruit, I bought some and still have them in fridge. My father in law says that there is worm in dragon fruit don't eat. Emm.. I don't know if it is true or not, how about you? Why is there worm in dragon fruit? Who would still purchase the fruit to eat? Even durian sometimes we see worm inside but we wouldn't eat the worm part of durian. Anyway I still eat dragon fruit.