20.500.12556/DiRROS-28843 Polarization vision and the physiological basis for trichromatic vision in Philaenus spumarius understanding host-seeking behaviour in insect vectors for Xylella fastidiosa control In European outbreaks, the meadow spittlebug Philaenus spumarius is the primary vector of the xylem-limited bacterium Xylella fastidiosa. The mechanisms underlying host plant location by spittlebugs—critical for the transmission of associated bacterial pathogens—remain poorly understood, particularly with respect to the potential role of visual cues. Here, we investigated the visual system of P. spumarius through an integrated anatomical, optical, physiological, and behavioural approach to explore the potential role of vision in host-seeking behaviour. Using microscopy, 3D reconstructions, and single-cell recordings, we examined the structure and function of the compound eyes. Optical mapping revealed relatively low spatial resolution, with interommatidial angles of 4°–8° and somewhat smaller angles and finer visual sampling in central and anterior-ventral regions. Intracellular recordings showed that photoreceptors are maximally sensitive to ultraviolet (UV), blue (B), and green (G) light, suggesting the potential for trichromatic colour vision. UV and B-sensitive photoreceptors exhibited high polarization sensitivity (PS), with UV and B photoreceptors maximally sensitive to vertically and horizontally or obliquely polarized light, respectively. The physiological evidence indicating that polarized light is detected primarily by UV and B photoreceptors was complemented by the observation of orthogonally arranged microvilli in anatomical cross-sections of the retina, which might belong to polarization-opponent photoreceptor pairs with orthogonal sensitivity maxima to polarized light. Behavioural tests in a Y-maze demonstrated that starved spittlebugs preferred linearly polarized over a diffuse visual stimulus. This preference disappeared when a yellow filter blocked UV and blue light, implicating the necessity of UV and B photoreceptors for the detection of polarized reflections. Our findings demonstrate that P. spumarius uses visual cues, including polarized light, which may aid in the visual detection of reflections from host plants. Understanding these visual mechanisms provides new insight into the ecology of this key vector species and may inform strategies to disrupt its host-finding behaviour. host finding insect behaviour polarotaxis circadian rhythm trichromatic vision visual acuity visual system iskanje gostitelja vedenje žuželk polarotaksa trikromatski vid ločljivost vida vidni sistem true false true Angleški jezik Slovenski jezik Neznano 2026-04-09 11:55:58 2026-04-09 11:55:59 2026-04-10 03:55:38 0000-00-00 00:00:00 2026 0 0 Nasl. z nasl. zaslona; Opis vira z dne 20. 10. 2025; str. 503-519 issue 2 Vol. 188 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 595 1744-7348 10.1111/aab.70065 253874435 RAZ_Lazar_Domen_2026.pdf RAZ_Lazar_Domen_2026.pdf 1 49784FF48C9CC51486A802349B773EA9 b2c5e89f9a372a3f81a0b2e9f355dfe31ff0b8ba65a2e6caf65fd8d73d5afc4f 745ba924-33fa-11f1-b941-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=42984 https://onlinelibrary.wiley.com/doi/10.1111/aab.70065 1 51d6445b-33fa-11f1-b941-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=42983 Univerzitetni klinični center Ljubljana 0 0 0