A Preliminary Study on Identifying the Predator Community of Invasive Bactericera cockerelli (Hemiptera: Triozidae) and Developing Molecular Identification Tools for Testing Field Predation.

Abstract

The tomato potato psyllid Bactericera cockerelli (Hemiptera: Triozidae) is a significant insect pest of Solanaceae. In early 2017, it was first detected in Perth, Western Australia. The objective of this work was to identify predator species of B. cockerelli occurring in fields of Solanaceae in Western Australia. Predatory insects and arachnids were sampled using sweep netting in some of the major Solanaceae-growing regions in the south-west of Western Australia in 2021 and 2022. Several laboratory feeding trials were conducted to develop PCR primers that could detect the DNA of B. cockerelli in predators that had fed on B. cockerelli rather than on alternative diets. The primers were then used to screen predators collected from the field to identify those that had been feeding on B. cockerelli. In the two years of field sampling, the predators collected represented a broad taxonomic range. The most abundant predator was green lacewing followed by ladybirds. Further, we analysed predators belonging to seven insect taxa (one Neuroptera, two Hemiptera and four Coleoptera) for the presence of B. cockerelli DNA. We found that 45% of the individual insects from all taxa that we caught were positive for B. cockerelli DNA, and Coleopteran predators showed the highest rate of positive results. This is the first report confirming predation on invasive B. cockerelli by the resident predator community in the field in Australia.