They are attracted to the maturing fruit where they deposit their eggs. The eggs hatch and develop within the fruit, causing a break down of the fruit tissue. Control measures are field hygiene, bagging, use of poisoned baits and appplication of insecticides such as lebaycid. Fruit scabs affect immature fruits by causing a corky brown layer all over the fruits. This will cause the fruits to be unattractive and unmarketable.
Parasitic algae causes rust-like blemishes on the fruit surface.
When the algae disappears, dark necrotic blemishes are left on the fruit surface. Suitable fungicides and pruning will help to reduce these diseases. In Malaysia guava is available throughout the year although not always in the same quantities. Budded guava fruit within a year of planting. From flowering the fruits take about three months to mature.