Olive oil is very healthy fat obtained from the olive, a traditional tree crop of the Mediterranean Basin. The oil is produced by pressing fresh olives. It is commonly used in cooking and cosmetics. Here in Crete the cultivation of the olive tree is deeply rooted in the tradition of the island. The trees are perfectly adapted in the climate and soils of the island and this is the secret of producing an excellent oil. Nowadays, the main threat for olives is olive fruit fly, a species of fruit fly which feeds inside the fruit, destroying the pulp. The olive fly problem is treated by detection, monitoring and management. When it comes to detect and monitoring the olive fly, being vigilant, diligent and systematic is critical as fly population can multiply rapidly. In Crete, Greek government has appointed agriculturists to monitor populations in the spring with McPhail traps. When traps indicate that population is increasing in early summer, agriculturists give instruction to workshops to apply bait sprays. The traps are placed in different places throughout the region of Crete. The first application happens a week or two before pit hardening and it re-applies every 5 to 6 weeks during summer.