Spectral sensitivity of L2 biotype in the Thrips tabaci cryptic species complex

• Published in: Journal of insect physiology 2020-02, Vol.121, p.103999-103999, Article 103999
• Main Authors: Egri, Ádám, Farkas, Péter, Bernáth, Balázs, Guerin, Patrick M., Fail, József
• Format: Article
• Language: English
• Subjects: Adaptation, Ocular - physiology; Animals; Biotype; Classification; Compound Eye, Arthropod - physiology; Electroretinogram; Electroretinography - methods; ERG; Insect Control; Photophobia; Phototaxis; Phototaxis - physiology; Spectral sensitivity; Thrips; Thrips tabaci; Thysanoptera - classification; Thysanoptera - physiology
• ISSN: 0022-1910; 1879-1611
• DOI: 10.1016/j.jinsphys.2019.103999

[Display omitted] •Thrips tabaci is a cryptic species comlex consisting of 3 biotypes.•The spectral sensitivity of the most widespread biotype was studied.•Compound eyes are most sensitive to the green spectral region.•Action spectrum of phototaxis is bimodal with maxima in the UV-A and green regions. The onion thrips, Thrips tabaci (Lindeman, 1889), is a cosmopolitan pest of economic importance on a wide range of crops. Despite being one of the most studied thrips species, there is very limited knowledge available about its ability to perceive light. The T. tabaci cryptic species complex consists of a tobacco-associated (T) and two leek-associated (L1, L2) biotypes. We made electroretinogram recordings on the most widespread thelytokous (where unfertilized eggs produce females) T. tabaci L2 biotype and measured attraction to light sources in this biotype as a function of wavelength in behavioural experiments. The spectral sensitivity of the T. tabaci L2 biotype shows a unimodal curve peaking at λmax = 521 nm. Contrary to this spectral sensitivity curve, L2 biotype attraction in an arena is bimodal with local maxima at 368 nm (UV) and 506–520 nm (green) being practically of the same magnitude. Although being similar to the arrhenotokous (where unfertilized eggs produce males) L1 biotype in phototaxis, significant differences regarding photoreceptor cell responses emerged. This study contributes to our understanding of light perception in Thysanoptera as well as to the development of more effective monitoring tools for this economically important pest species.