Arthropod Biology Biology of Psyllaphycus diaphorinae (Hymenoptera: Encyrtidae), a Hyperparasitoid of Diaphorencyrtus aligarhensis (Hymenoptera: Encyrtidae) and Tamarixia radiata (Hymenoptera: Eulophidae)

The biology and ecology of Psyllaphycus diaphorinae Hayat, a potential natural enemy of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is poorly understood. In April 2013, six P. diaphorinae females collected from Punjab, Pakistan emerged from parasitized Asian citrus psyllid nymphs in quarantine at the University of California, Riverside and were used to initiate colonies. Contrary to previous claims, P. diaphorinae was found to be an obligate hyperparasitoid and not a primary parasitoid attacking Asian citrus psyllid nymphs. P. diaphorinae was able to successfully reproduce on both Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae) and Diaphorencyrtus aligarhensis (Shafee, Alam, and Agarwal) (Hymenoptera: Encyrtidae) pupae, both primary parasitoids of Asian citrus psyllid. No reproduction on unparasitized Asian citrus psyllid nymphs was observed. D. aligarhensis appears to be a preferred host in comparison to T. radiata, as P. diaphorinae produced a higher number of offspring and a higher proportion of females on D. aligarhensis.