Association of Ants with Mealybugs (Paracoccus marginatus) on Crystal Guava in West Lombok

The mealybug Paracoccus marginatus is a major pest of crystal guava (Psidium guajava L.), often associated with honeydew-seeking ants. However, these associations in the dryland areas of West Nusa Tenggara, Indonesia, remain poorly documented. This study identified ant taxa associated with mealybug colonies and analysed relationships among ant population, mealybug population, and attack intensity. An observational study was conducted in Gerung, West Lombok, from May to June 2026. Twenty infested trees in four blocks were observed weekly for five weeks. Ants and mealybugs were counted on four canopy sides, attack intensity was scored on a 0–4 scale, and ants were identified morphologically. Pearson correlation and diversity indices were used for analysis. Seven ant taxa from five subfamilies were identified, including four active or opportunistic mutualists, one facultative mutualist, and two predatory or incidental taxa. Mealybug and ant populations declined concurrently by approximately 53% and 52%, respectively, and were strongly correlated (r = 0.886, p < 0.001). Ant and mealybug populations were positively correlated with attack intensity (r = 0.659 and 0.871, respectively). Although these patterns are consistent with potential mutualism, the observational design does not establish causality. Ant management, including trunk barriers, may be considered in integrated pest management, pending further evaluation.