Electrophysiologically Determined Spectral Responses in Lobesia botrana (Lepidoptera: Tortricidae)

Abstract

Electrophysiological methods were used to test the visual sensitivity of European grapevine moth, Lobesia botrana (Lepidoptera: Tortricidae) to wavelengths ranging from 300 to 700 nm. For male and females tested, a main, peak response occurred in the 460–540 nm range (blue-green wavelengths) with females having a generally lower response to wavelengths in that range. A second smaller peak was observed for both sexes at the 340–420 nm range. A general linear model indicated that males, virgin females, and mated females did not react differently to changes in wavelength. No moths showed any obvious sensitivity to wavelengths between 580 and 700 nm. Based on our retinal recording data we suggest that UV light traps (≤480 nm) could be utilized alongside pheromone traps when monitoring L. botrana in high risk areas.

Spectral sensitivity of retinal photoreceptors of tortricid moths is not tuned to diel activity period

“…vision, based on UV, blue and green photoreceptors, and that it does not differ among species or between sexes. Similar results were obtained in other studies on Tortricidae (Satoh et al, 2017;Jakobsson et al, 2017;Crook et al, 2022). The studied tortricid moths thus have a generalist trichromatic colour vision substrate and do not show any fine tuning in the spectral sensitivity, in contrast to sphingid moths (Akiyama et al, 2022).…”

“…The regionalization of the tortricid moth retina, with the UV and blue receptors found in the dorsal and ventral parts, respectively, is very similar to that in the sphingid moth Manduca sexta (Bennett et al, 1997). In previous studies of tortricid moths, researchers have either failed to show the blue receptors (C. pomonella;Pristavsko et al, 1981) or take into account different parts of the eye (L. botrana; Crook et al, 2022), or have reported various levels of UV sensitivity across species from different photic environments (Eguchi et al, 1982), with increased UV sensitivity sometimes being attributed to the demands of nocturnal navigation (Ogawa et al, 2015;Barta and Horváth, 2004). We suggest that the results from these studies should be treated with caution, and that more attention should be paid to potential effects associated with the recording position in the retina.…”

“…A comparative study of the visual system of these three moth species could provide valuable information regarding insect evolutionary adaptations to diurnal and nocturnal conditions. Furthermore, there are only four other studies on the spectral sensitivity in tortricids moths, on C. pomonella (Pristavko et al, 1981), L. botrana (Crook et al, 2022), Cydia strobilella (Jakobsson et al, 2017) and Adoxophies orana (Satoh et al, 2017). In addition, the exploration of the visual physiology of these economically important insect species could provide valuable insights into how to exploit their visual system for pest control (Shimoda and Honda, 2013).…”

Increasing catches of adult moth pests (Lepidoptera: Tortricidae) in pome fruit with low‐intensity LED lights added to sex pheromone/kairomone lure‐baited traps

“…A laboratory study with OFM found peak attraction to wavelengths at 405 nm followed by 540 nm, and attraction was demonstrated to be positively correlated with light intensity generated by 12-60 LED lights (Sun et al, 2014). A laboratory electroretinogram study with L. botrana showed that the compound eyes of both moth sexes were most responsive to blue-green light (460-540 nm), and a second smaller peak occurred to UV light (340-420 nm) (Crook et al, 2022). They also found that mated and virgin females responded similarly.…”

“…LED lights with refined radiation spectra can be engineered for specific purposes (Bae et al, 2015; Nabli et al, 1999; Park & Lee, 2016). To date, the influence of specific radiation spectra on the attraction of tortricids is limited (Crook et al, 2022; Naton, 1972; Sun et al, 2014).…”