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

Abstract

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.

Habitat heterogeneity reduces abundance of invasive mealybugs in subtropical fruit crops

“…The models showed that maintaining more than 10% ground cover by non-crop vegetation within the orchards and more than 15% of semi-natural habitats in the surrounding landscape can suppress P. longispinus by increasing its parasitism in persimmon. Although the economic injury levels of P. longispinus in persimmon have not yet been determined (Plata, Gómez-Martínez, et al, 2023a), these recommendations could significantly reduce mealybug abundance and fruit damage. However, long-term landscape planning remains a challenge, emphasizing the need for policymakers and stakeholders to optimize the management of invasive pests such as mealybugs.…”

“…Nine alternate trees were selected per plot and sampled across the study (Figure S2). For each tree and sampling date, we counted and identified the mealybugs present in 120 leaves (30 per cardinal direction), 40 fruits (10 per cardinal direction) and the trunk surface (from ground level to 50 cm height) (Plata, Gómez-Martínez, et al, 2023a). All observed mealybugs were identified up to the species level using taxonomic keys (e.g.…”

“…Data available from IVIA repository, https://doi.org/10.58582/redivia.8759 (Plata, Tena, et al., 2023).…”

“…In Spain, invasive mealybugs have become key pests in two important subtropical crops: citrus and persimmon (Martínez-Blay et al, 2018;Plata, Gómez-Martínez, et al, 2023a). Delottococcus aberiae, native to South Africa, is the prevalent mealybug in citrus, while Pseudococcus longispinus, from Australia, is the prevalent species in persimmon.…”