Bioecological characteristics of Planococcus citri Risso, 1813 (Hemiptera: Pseudococcidae) under constant and alternating temperatures

Planococcus citri Risso, 1813 (Hemiptera: Pseudococcidae), is one of the major pest of citrus and many other orchards crops, and ornamental plants in subtropical and tropical regions of the world. The influence of temperature on P. citri development and fecundity has a critical role in integrated pest management strategies to reduce the population to below the economic threshold by biological or chemical control methods. The study investigated some bioecological characteristics, such as, development time, duration of biological stages, sex ratio, daily and total fecundity per female, and longevity of P. citri, under different temperature regimes during 2015-2016 in Citrus Pest Laboratory at Cukurova University. The shortest egg stage development for females and males were determined as 2.7 and 2.7 d with alternating temperatures of 25/30 degrees C (12:12h), respectively. The first nymph stage lasted 7.86 d for females, and 8.1 d for males at 25 degrees C. The longest duration for the second nymph stage was obtained at 15 degrees C with 25.7 and 22.5 d for females and males, respectively. The third nymph stage for P. citri females completed in 7.0 d at 25 degrees C, and the pupal stage for P. citri males lasted 7.8 d at 25 degrees C. The development thresholds of females and males were calculated as 8.5 and 9.5 degrees C, respectively. Also, thermal constants of females and males were 666.67 and 500.00 degree-days. The optimum development temperature was determined as 25/30 degrees C.