I've noticed that covering fruit is not practiced much in our country. It is quite popular in Thailand and my mother-in-law over there painstakingly does this with the majority of their fruit. Sure pays to keep the trees pruned a bit short, eh? If there is not a squirrel or insect issue, may not be worth the hassel.

You don't need to bag Mangoes. Guavas are attacked by fruit flies in some areas (like where I live) and bagging them is common. But it is a pain, and requires constant checking/adjusting of the bags. Squirrels learn very quickly that bags in a tree mean food, and they rip them right off, and steal the fruits. A high-powered air rifle works best on them.

In zone 9, you may be okay as far as fruit flies.

Infestation is spotty.

Plain brown lunch bags worked better for me than the expensive bags I bought that they use in Japan commercially to bag fruits. Bags need to be changed after heavy rains, and high winds blow them off.

Were your Guavas free of maggots? if so, you may not need to bag, at least until the fruit flies find your trees. Clean up any fallen fruits.

Lisa

They do that most commonly to bananas, I think its to protect the fruit from insects. The kind of bags I've seen used on them tend to be blue, but you could probably research a little to see if it matters or not.

Luckily I don't have a problem with my fruits yet, but people here say that guavas are full of protein (due to the maggots)!
Ever since I heard that, I always check the fruit before I eat it!