# Rapid Detection of Philaenus italosignus Drosopoulos & Remane, 2000 (Hemiptera: Aphrophoridae) with Real-Time PCR Probe LNA Technology

## TL;DR

This paper introduces a fast and reliable molecular test using LNA probe technology to identify the insect Philaenus italosignus, a key vector of the plant pathogen Xylella fastidiosa.

## Contribution

A novel real-time PCR test with LNA probe technology for rapid and accurate identification of Philaenus italosignus, overcoming morphological identification challenges.

## Key findings

- The LNA qPCR test reliably identifies all instars of P. italosignus, improving vector population surveys.
- The method allows discrimination between P. italosignus and other Xylella vectors in the field.
- The test enhances the accuracy of Xylella IPM-DSS strategies by enabling precise vector census.

## Abstract

This biomolecular diagnostic test for the rapid identification of Philaenus italosignus Drosopoulos & Remane, 2000, is valuable in identifying one of the hemipteran species involved in the Italian invasion of Xylella fastidiosa Wells et al., 1987. The test utilizes a locked nucleic acid (LNA) probe, which increases the probe’s affinity with the target, thus ensuring higher specificity. The new qPCR test with LNA probe has proven to be a more reliable and reproducible method for identifying the different instars of P. italosignus, thereby improving territorial surveys for X. fastidiosa vector population management strategies and allowing discrimination between species collected in the field.

To date, Philaenus spumarius (Linnaeus, 1758), Philaenus italosignus Drosopoulos & Remane, 2000, and Neophilaenus campestris (Fallén, 1805) are proven vectors of the phytopathogenic bacterium Xylella fastidiosa Wells et al., 1987 in Europe. Currently, the identification of these three species relies on the well-documented status of morphological and taxonomical characters, making the discrimination of vector adult males possible by genitalia comparison. This study updates the biomolecular diagnostic tests with a rapid identification tool for P. italosignus, using locked nucleic acid (LNA) probe technology. The test also overcomes the difficulties associated with the morphological identification of females and juveniles. The morphological α-taxonomic identification of the male, achieved through comparison with the type of the species, retains its primary role in specimen identification for probe building. Later, the proposed assay can contribute to the rapid identification of P. italosignus by the secondary (molecular) identification step. The new LNA qPCR test offers high reliability and reproducibility in the identification of P. italosignus instars, thus improving targeted surveys of X. fastidiosa vector populations and allowing discrimination between species collected in the field. The accurate identification and census of vector individuals, regardless of their gender and instar, enhances the efficacy of Xylella IPM-DSS (Integrated Pest Management Decision Support System) strategies.