Olive fly (Bactrocera oleae) activity, fruit infestation and temperature in an organic table olive orchard in southern Crete

Olive fly activity and olive fruit infestation was monitored in a table olive orchard in southern Crete throughout most of 2006 using McPhail traps. Flies were trapped weekly for 40 weeks, starting at the beginning of February. The fly data was split into 10 four-week periods. Male, female and total fly activity was significantly related to sampling period, maximum temperature and relative humidity but the pattern of catches was not consistent. Activity increased from February until July but declined in August and was very low in September, October and November. The low activity in the last three months was reflected in low fruit infestation levels, with a maximum of 3.6% in October which contrasts with infestation levels usually around 30%. Olive fly mortality is high above 31oC and the average mean maximum temperature in the four months June-September was above 34oC. High summer temperatures, with low humidities, appear to have considerably limited olive fly activity and fruit infestation and pest control measures may have to be adapted to these conditions