The olive fruit fly Bactrocera oleae is the most important olive pest. This study was conducted in El Matarih, Marsa Matrouh in Matrouh Governorate, Egypt during 2013 and 2014, to illustrate the relationship between adult captures occurred in McPhail traps and in soil cages inactivity period (from January to May) and their effects on the infestation levels on olive fruits in active period (from June to November). In McPhail traps, data showed two main peaks inactivity periods, the first peak was in March and the second was in May. Data demonstrated that adults by the 1st of January was in a relatively low number (about 7.5 adults)  and increased gradually to reach its main peak on March, where the average number reached about 117.2 adults and the second peak with value of 116.2 adults in May. McPhail traps caught female adults more than male and captured (74.7 and 73.5) and (42.5 and 42.7) in female and male adults in March and May months, respectively. In soil cages, the average number of adults were decreased sharply throughout the successive inspection and reached the lowest numbers (1.4 adults/10 cages) in January. The average number of emerged adults were increased gradually in the successive inspection and reached the second highest average numbers (22.5 adults/10 cages) in March. Also, adult females were found to be more dominant than males and recorded the highest average numbers in December, 2013 (30.6 adult females/cage) and recorded the lowest average numbers in January, 2013 (0.9 adult females). Based on our data in the activity period, the cumulative average number of total infested fruits, larvae and pupa as affected by dimethoate spraying and mass trapping in inactivity period were (14.0, 3.2 and 3.6) and (22.8, 5.8 and 5.9), respectively, as compared with (83.9, 20.7 and 21.2) fruits in the untreated control treatment, representing (83.3, 84.5 and 83.0%) and (72.8, 72.0 and 72.2%) reduction of infestations, respectively.  These observations support some of recommendations to control olive fruit fly by removing pupa in the soil, destroying fruit left on the tree after harvest and mass trapping of olive fruit fly inactivity period. In addition to this natural control, there are no pollutants in olive fruit and its oil contents. The obtained data support that it is possible to carry out previous recommendations in inactivity period in order to prevent or reduce adulticide treatments to improve IPM or organic management in areas where high infestation is expected.