Optimization of predation condition of three Orius species (Heteroptera: Anthocoridae) with adjustable relative humidity using central composite design

The concept of natural enemies efficiency in different physical conditions is one of the issues which is permanently discussed and analyzed by researchers in pest management programs. The question of relative humidity control in greenhouse condition is seriously significant to preserve natural enemies’ efficiency for controlling pest considering the importance of greenhouse products cultivation in studied area and locating these areas in Iran plateau dry belt. In present study optimization and suitable relative humidity for predatory bugs Orius albidipennis (Reuter), Orius laevigatus (Fieber), and Orius niger (Wolff) was determined by using central composition design model. Central composition design model was applied for the first time to analyze efficiency of natural enemies in physical conditions (relative humidity). Results revealed that relative humidity change significantly affected predation amount of Orius predatory bugs and demonstrated that in 60 to 70 percent of relative humidity, O. niger species with percentage of 88.6 had the most predation and O.albidipennis species with 59 percent had the least predation from E. kuhniella eggs. Consequently it was confirmed that O. niger and O. laevigatus species had predation from E. kuhniella eggs in high relative humidity conditions comparing with O. albidipennis species. This may be related to adaptability of O. niger and O. laevigatus species to Mediterranean regions unlike O. albidipennis species which is adapted to arid and semi-arid lands.