The potential of the small big-headed ant (Pheidole parva) (Hymenoptera: Formicidae) as a biocontrol agent for the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae).

Diaphorina citri Kuwayama (Hemiptera: Liviidae), the Asian citrus psyllid, threatens global citrus production by transmitting Candidatus Liberibacter asiaticus, the causal agent of Huanglongbing (HLB), a destructive disease causing severe yield losses. This study evaluated the ant species Pheidole parva Mayr (Hymenoptera: Formicidae) as a biological control agent against D. citri. Using morphological identification and mitochondrial COI gene sequencing, P. parva was confirmed as a dominant psyllid predator. Behavioral observations revealed a preference for preying on early nymphal instars (first to third) over late nymphs and adults. Functional response modeling showed a Holling Type II pattern, where predation rate increased with prey density but plateaued due to handling time constraints. Additionally, search efficiency decreased with rising ant density, aligning with the Hassell-Varley model and indicating intraspecific foraging interference. These findings highlight P. parva's efficacy in suppressing D. citri populations, particularly HLB-transmission-critical nymphs. By elucidating ant-psyllid interaction dynamics via ecological models, this research supported integrating P. parva into sustainable pest management. Further studies on field deployment and ecological compatibility are recommended to maximize its predatory potential, mitigate HLB impacts, and enhance citrus production resilience. The findings provided empirical support for using P. parva in integrated pest management programs against D. citri.