Mealybugs in Mediterranean persimmon: fruit infestation, seasonal trend and effect of climate change

Mealybugs (Hemiptera: Pseudococcidae) are the main pest of persimmon in Spain, the second producer in the world. In order to develop an Integrated Pest Management (IPM) program, it is necessary to identify the main mealybug species, determine their phenology, and develop tools to predict damage. To do this, we sampled 17 orchards from the main persimmon producing area in Spain over two years. Pseudococcus longispinus (Targioni-Tozzeti) was the most abundant and widely distributed species. This mealybug species completed three generations per year and reached peak density just before harvest. Fruit infestation at harvest was highly correlated with mealybug density in spring and summer. The estimated thermal constants to complete development and one generation were 512.5 and 956.3 degree days, respectively. Based on climate change predictions, crop damage caused by the third generation of P. longispinus will increase in 2040 and the mealybug will complete a fourth generation by 2080. Pseudococcus longispinus has become the main pest for Mediterranean persimmon and damage produced by this mealybug may be exacerbated by climate change. This work provides essential data to design a sampling protocol and determine intervention times and thresholds against this mealybug.