Interaction Dynamics and Comparative Biology of Two Hymenopterous Parasitoids of Diaphorina citri Kuwayama

Huanglongbing (HLB) is the most serious disease affecting citrus production worldwide, and its management relies on controlling its vector, Diaphorina citri. Although Tamarixia radiata (Waterston) is widely used in biological control programmes, Diaphorencyrtus aligarhensis (Shafee et al.) has been proposed as a complementary agent; both species were reported in Colombia in 2016, yet their interaction dynamics under local conditions remain poorly understood. This study evaluated the development, morphometry, and interaction patterns of both parasitoids under controlled rearing conditions using a shared host population. Three treatments were established: non-parasitised nymphs, nymphs exposed to D. aligarhensis, and nymphs exposed to T. radiata, with parasitoids allowed to oviposit for 24 h. Developmental duration and morphometric traits were recorded daily. T. radiata completed its life cycle in less time (~11.7 days) than D. aligarhensis (~14.4 days) and than non-parasitized nymphs (~17 days). Morphometric traits were consistent with previously reported ranges, and this study provides the first detailed characterisation of the immature stages of D. aligarhensis in Colombia. Particularly, events of multiparasitoidism and superparasitoidism were documented under standardised conditions, demonstrating that both species can exploit the same host simultaneously. These findings offer new insights into parasitoid interaction dynamics and establish a biological foundation for developing integrated biological control strategies against D. citri.