Seasonal Dynamics and Spatial Distribution of Planococcus citri (Hemiptera: Pseudococcidae) in Citrus Orchards

Abstract

Seasonal dynamics and spatial distribution of Planococcus citri (Hemiptera: Pseudococcidae) were investigated in citrus orchards to understand its population fluctuations, infestation patterns, and environmental drivers under field conditions. Systematic surveys were conducted across different orchards and sampling points on leaves, shoots, and fruits to quantify mealybug abundance throughout the growing season. Results indicated distinct seasonal population trends, with peak infestations occurring during warm and moderately humid periods that favor rapid reproduction and overlapping generations. Early vegetative and fruiting stages of citrus were particularly susceptible, with increasing population buildup observed as the canopy developed and microclimatic conditions stabilized. Spatial distribution analysis revealed an aggregated pattern of infestation, with higher densities concentrated on tender shoots and fruit clusters, forming localized hotspots within orchards. Peripheral orchard zones exhibited higher initial colonization, suggesting edge-driven dispersal and progressive inward spread. Environmental factors such as temperature, relative humidity, and host phenology significantly influenced population growth and distribution patterns. Natural enemy presence, including parasitoids and predatory insects, contributed to partial regulation of mealybug populations, although their impact was insufficient to prevent periodic outbreaks. The study highlights the importance of understanding spatial aggregation and seasonal trends for effective monitoring and targeted management of P. citri. These findings support the development of integrated pest management strategies incorporating timely interventions, biological control conservation, and orchard sanitation practices to reduce mealybug infestations and minimize yield and quality losses in citrus production systems.