After the first stage of fruit formation, it attacks the young fruit, penetrating it laterally via the receptacle. Depending on the season, it also attacks tender young shoots and leaves which it joins together to form a web. It also penetrates developed fruits by boring a gallery in the skin. Also, on account of the large number of generations each year, P. citri is found in all stages of development every month of the year. The attacked young fruits, devoured from the inside and soiled by frass, are aborted.
More mature fruit is deformed and remains small.