Assessing collection and trapping methods for diagnostics and surveillance of psyllids (Hemiptera: Psylloidea) in and around citrus orchards

The economic impacts of Huanglongbing disease have prompted global surveillance of citrus psyllid vectors. While yellow sticky traps (YSTs) are widely used to detect pests such as the African citrus psyllid (Trioza erytreae) and the Asian citrus psyllid (Diaphorina citri), alternative methods may capture unique species and greater taxa richness and abundance, which could impact downstream species identification and diagnostics. We assessed psyllid richness and abundance across 4 sites within major citrus-growing regions of eastern Australia, and found that combining hand sampling with YSTs captured more species compared to light trapping and pan traps, but all sampling techniques collected unique taxa. Species were identified via an integrative taxonomy approach combining host plant data, morphology, and DNA sequences. We generated 196 cytochrome oxidase reference sequences from 87 species, 27 genera, and 5 families. Of these, 65 morphospecies and a described species were previously unrecorded in public DNA databases. This allowed us to build a baseline reference for eastern Australian native psyllids found around citrus orchard environments, thereby enhancing species-level molecular identification, and strengthening surveillance and biosecurity in Australia.