Monitoring studies revealed occurrence of Bactrocera dorsalis, B. correcta and B. zonata throughout the year in guava, at Dharwad.  Peak catch of B. dosalis was observed during 30th standard week (27.16 fruit flies) in 2003, and also a small peak during 1st standard week (2.03 fruit flies )  in 2004.  Two peaks of B. correcta were observed during 30th (123.69 fruit flies) and 45th standard weeks (362.67 fruit flies) in 2003.  In 2004, no significant peak was observed.  B. zonata had three major peaks during 42nd standard week (15.19 fruit fleis) in 2003 and 11th and 12th standard weeks in 2004 with 17.71 fruit flies.  When total number of fruit flies was considered, three peaks were observed during 30th (157.64 fruit flies), 43rd (218.75 fruit flies)  and 45th (379.82 fruit fleis) standard weeks in 2003.  In 2004, major peak was during 3rd (107.10 fruit flies) standard week.  All weather parameters together influenced trap catches of B. dosalis, B. correcta and B. zonata  to the extent of 56.70 , 12.0 and 53.30 per cent.