This study was carried out to study the effect of infested carnation plants (Dianthus caryophyllus L.) by Carnation Thrips, Haplothrips cottei (Vuillet) (Thysanoptera: Thripidae) andBemisia tabaci (Gennadius) on the quantity of annual production of carnation flowers under glasshouse conditions at three locations (governorates), International Garden (Cairo Governorate), El-Orman Garden, (Giza Governorate) and International Garden (Alexandria Governorate) during successive season 2018, 2019.
         Therefore, this study was divided into three parts, the first part studied population fluctuation of H. cottei andB. tabacion the carnation plants during successive season. The second part studied the effect of infested carnation plants by the two insects on the quantity of annual production of carnation flowers at the three locations. And the third part studied the effect of insect infestation by the two insects on the internal components of carnation plants.         
         Results obtained showed that the infestation by H. cottei reduced the quantity of annual production of carnation flowers after picking more the infestation byB. tabaci compared to control (which non infested by the same insects). Also, results showed that the infestation by H. cottei reduced total sugar and total protein as the infested carnation flowers more than the infestation byB. tabacicompared to control.