Effect of temperature on the reproductive parameters and survival of Cenopalpus irani dosse (Tenuipalpidae)

Abstract

Cenopalpus irani (Tenuipalpidae) is one of the main pests of apple trees in the Western regions of Iran. We studied the effect of six constant temperatures of 15, 20, 25, 30, 32 and 33.5°C on the reproductive parameters, life expectancy and the mortality rate of C. irani immature stages at 50 ± 5% relative humidity (RH) and a photoperiod of 16:8 (light : dark) h fed on apple leaves. The highest and lowest gross fecundity rate were observed at 30 oC (34.60 eggs/female) and 15oC (18.50 eggs/female), respectively. The maximum gross fertility rate was 32.87 (eggs/female) at 30oC, whereas the minimum value was 9.94 eggs/female which obtained at 15oC. As increasing temperature from 15°C to 30°C, the gross hatching rate increased and then decreased at 33.5°C. The highest and lowest life expectancy (ex) were obtained at 83 and 27th days, at 15°C and 33.5°C, respectively. Also, the highest and lowest values of mortality percentage for immature stages of C. irani were recorded at 15oC and 30oC, respectively. As increasing temperature the reproductive value (Vx) increased from 15°C (5.95 females/female) to 30°C (9.27 females/female), then decreased at 33.5°C (5.61 females/female). The finding of this research can be used for establishing integrated pest management (IPM) strategies against C. irani in apple orchards.