Seasonal abundance of natural predators and parasitoids associated with the cotton mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) in okra agro-ecosystems of southern Turkey

Abstract:

Documentation of the natural enemy complex associated with invasive mealybug pests constitutes a fundamental prerequisite for designing conservation biological control programmes. This research catalogued and quantified the seasonal abundance patterns of predators and parasitoids associated with Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) on okra (Abelmoschus esculentus L.) in the Mediterranean coastal agro-ecosystems of southern Turkey during 2022-2023. Systematic weekly sampling across twelve months identified three functional groups of natural enemies: coccinellid predators (6 species), chrysopid predators (3 species), and encyrtid parasitoids (2 species). Coccinellid predators constituted the dominant functional group, reaching peak abundances of 38.6 individuals per ten plants during July, with Cryptolaemus montrouzieri Mulsant as the most abundant species. Chrysopid predators peaked at 30.2 individuals per ten plants during July, dominated by Chrysoperla carnea Stephens. Parasitoid activity was lower overall, peaking at 26.8 individuals per ten plants. Seasonal abundance of all natural enemy groups showed significant positive correlation with P. solenopsis population density, with a temporal lag of 2-3 weeks. The predator-prey ratio analysis revealed that combined natural enemy activity maintained mealybug populations below economic threshold levels during spring but was insufficient to prevent population escalation during the high-temperature summer months. These findings establish a baseline inventory of the P. solenopsis natural enemy complex on okra in the eastern Mediterranean and identify candidate species for augmentative biological control programmes.