Life cycle
Adult beetles lay their eggs in rotting or damaged fruit. The larvae emerge from the fruit and enter the soil where they pupate.
Adults emerge from the ground and attack ripening fruit. The life cycle takes only a month in summer so there are several generations in a year.
The adults are strong fliers and can travel between orchards. They prefer summer rainfall and abundance of rotting fruit.
If no hosts are available they overwinter in cracks in the tree, under bark or in mummified fruit.
Damage
Most commercial feeding damage is done to ripening stone fruit.
Stone fruit can be attacked on the tree, beetles burrow into the fruit, particularly near the stem end suture line. They also enter through splits and mechanical damage.
In other fruits such as citrus and apples, only fallen fruit is attacked.
See this article in Tree Fruit March 2017
