Identification of Plant DNA in Adults of the Phytoplasma Vector Helps Understanding Its Feeding Behavior.

Apple proliferation is an economically important disease and a threat for commercial apple cultivation. The causative pathogen, the bacterium ' Phytoplasma mali', is mainly transmitted by , a phloem-feeding insect that develops on the apple tree ( spp.). To investigate the feeding behavior of adults of the phytoplasma vector in more detail, we used deep sequencing technology to identify plant-specific DNA ingested by the insect. Adult psyllids were collected in different apple orchards in the Trentino-South Tyrol region of northern Italy. DNA from the whole body of the insect was extracted and analyzed for the presence of plant DNA by performing PCR with two plant-specific primers that target the chloroplast regions and . DNA from 23 plant genera () and four plant families () of woody and herbaceous plant taxa was detected. Up to six and three plant genera and families, respectively, could be determined in single specimens. The results of this study contribute to a better understanding of the feeding behavior of adult .