Monitoring flight activity of Tropinota squalida ssp. pilosa (coleoptera: cetoniidae) in relation to apple flowers phenology in Central West Tunisia

During the last decade, the hairy rose beetle, Tropinota squalida ssp. pilosa (Brulle) (Coleoptera: Scarabaeidae), represents a recrudescent subspecies in fruit orchards of Central west Tunisia. This pest destroys flowers of pome- and stone-fruit species by feeding on their reproductive organs. The main goal of this study was to provide fundamental information on the flight activity of this pest in an attempt to find and establish effective control methods against it. The study was conducted in apple orchards of Foussena, located in Central west Tunisia, during springs of the years 2017, 2021 and 2022. Water traps used in field experiments were placed between rows of trees to capture the beetles. The results showed that the activity of beetles was closely associated with the temperature rise and apple blossom onset. Over three years, we observed seven weeks of flight activity in the field. This activity commenced in early March within orchards featuring early varieties where it lasted for 4 to 5 weeks. Following that, the activity came to a close after 3 weeks by late April in apple orchards with autumnal varieties. The most significant captures (50%) occurred in the second half of March. The flight pattern exhibited only one peak in the third week of March, suggesting that T. squalida pilosa is a monovoltine species.