Faculty of Agriculture / University of Kerbala has discussed the M.A. thesis which deals with predicting appearance of different phases of two-spotted mite Tetranychus urticae (Koch) (Acari: Tetranychidae) in field, by calculating thermal units (Degree-Days) in laboratory conditions).
The study aims at investigating seasonal occurrence of two-spotted mites in field by calculating their numerical density and their relationship to temperature and relative humidity.
The study demonstrates possibility of determining thermal requirements necessary for development of different phases of the mite in the field, which contributes to early prediction of their appearance and monitoring them before they reach level of economic damage.
The study recommends the need to rely on thermal unit system programme in making control decisions and avoid using pre-determined timetables.