Got a 5 metre starfruit tree that is producing a lot of fruit. Problem is that all the fruit has some discoloration and bruising. It turns a brownish color and goes soft. Wife say's it's worms but having looked inside the fruit, don't see anything. I have started to wrap the fruit now but is there an organic spray I could use instead? Anyone had this?

Possible anthracnose fungus disease. (Colletotrichum gleosporoides) 

Starfruit is also known as carambola tree, Averrhoa carambola. Search for info and images to identify the condition and get tips on culture. 

A quick-fix spray application for advanced infections is not feasible. Covering, netting may not be appropriate or effective. Preventive management is best. Build natural resistance to disease by addressing plant health with good growing conditions, soil fertility and water managment. 

 

Fruit fly problem. I have it too. You can try traps but need the proper pheromone to lure the flies in them. I catch lots of mango flies with them.

https://www.lazada.co.th/products/fly-reusable-traps-fruit-fly-traps-fly-catcher-outdoor-i4800957482-s19843284860.html

https://www.lazada.co.th/products/codin-stock10-orchard-drosophila-i5013035860-s21186981524.html