Prototype 3D-Printed Traps Capture Bactericera cockerelli (Šulc) (Hemiptera: Triozidae) Directly into Preservative for Improved Detection of “Candidatus Liberibacter solanacearum”

Abstract

Potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), is a key pest of potato (Solanum tuberosum L.) and other solanaceous crops (Solanales: Solanaceae) as a vector of “Candidatus Liberibacter solanacearum” (Lso), the pathogen associated with zebra chip disease of potato. Potato psyllid populations typically are monitored using sticky card traps, and psyllids collected from sticky traps often are subjected to polymerase chain reaction (PCR) to monitor the incidence of Lso within psyllid populations. Psyllids collected from sticky traps are often mangled, desiccated, and coated with sticky residue, which may interfere with detection of Lso by PCR. A recently developed prototype 3-dimensional-printed trap that captures insects directly into a preservative (70% ethanol) was previously tested for monitoring psyllid populations. The capture of psyllids directly into a preservative may reduce degradation of DNA or protect specimens from PCR-inhibiting contaminants, thus improving the detection of Lso by PCR. Our goal was to compare the detectability of Lso in psyllids captured into preservative (prototype trap) to that in psyllids removed from sticky card traps. Overall, detection rates were higher in psyllids from the prototype trap than from sticky card traps. This improvement in Lso detection appeared to be partly due to the specimens yielding more DNA of higher quality. Results of this study demonstrate that compared with sticky card traps, a trap that captures psyllids directly into a preservative provides higher quality specimens for collection of molecular data, including pathogen diagnosis, population genetics, and molecular gut content analysis.