The temperature-dependent development of Pseudaulacaspis pentagona (Hemiptera: Diaspididae) on Morus alba and Morus nigra

Pseudaulacaspis pentagona Targioni-Tozzetti (Hemiptera: Diaspididae), is an important thermophilic, invasive, and polyphagous pest, especially of fruit trees. Here we report an investigation of physiological characters of P. pentagona that are important for predicting its phenology, including its development time at different temperatures, and its maximum, optimum, and minimum development thresholds. The research was conducted in 7 different temperatures (20.6, 23.2, 27.1, 29.0, 30.6, 31.3, 33.8 degrees C) on two mulberry species (Morus alba and M. nigra) in a climate chamber with fixed illumination regime (16: 8 h) and relative humidity (60 +/- 5%) conditions. The development times of P. pentagona nymphs under fixed conditions at above-given temperatures in ascending order were determined 33.49, 25.55, 18.63, 19.16, 21.99, and 24.84 days on M. alba while they were 32.85, 28.34, 20.98, 19.04, 19.66, and 24.99 days on M. nigra, respectively. The development threshold (C) and thermal constant (K) value of P. pentagona were calculated according to the Linear model as 12.48 degrees C and 272.526 day-degrees on M. alba, while 9.73 degrees C and 368.25 day-degrees on M. nigra, respectively. The minimum (Tmin), the optimum (Topt) and the maximum temperature (Tmax) requirements for the development of P. pentagona on these species were estimated with nonlinear models at a range of 14.15-16.5 degrees C, 27.5-28.3 degrees C, and 32.6-35.3 degrees C for M. alba, while 9.7-15, 28.2-29.7 and 32.4-37.3 for M. nigra species, respectively. The range in degree-days required for crawler emergence time of P. pentagona using the standard base temperature of 12.58 were estimated as 43-92 DD, 544-690 DD and 1120-1376 DD for first, second and third generation in three districts in Ankara, respectively. The results will provide information about the adaptation of P. pentagona to different geographical regions and climatic conditions and will also help determine the most effective application time in the control of this insect pest.