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Insects control their flight toward a distant odour source by integrating multimodal sensory information, such as olfactory and visual information. Control of flight speed in orientation flight toward an odour source using visual patterning below has been observed in many species of moths. However, there are few reports about moth flight behaviour over solid‐coloured floors. To examine, which visual stimuli affect flight behaviour of moths, male smaller tea tortrix (Adoxophyes honmai) were released in a pheromone plume over two striped floors (longitudinal and transverse stripes) and two unpatterned floors (solid white and solid black). Flight behaviours were videotaped, and upwind flight speed, height (altitude) and the number of backward movements moths made as they approached the pheromone source were determined. Male moths significantly increased mean and maximum upwind flight speed over longitudinal stripes relative to their speed over transverse stripes. Their speed over a solid black floor was the fastest of all floor patterns tested. As males approached the pheromone source, their mean upwind speed decreased significantly over all floor patterns, except for the black floor. Fewer moths made backward movements over the black floor compared with the other three floors. In addition, male moths flew significantly higher over the white floor than over the other three floors, while 60–40 cm from the pheromone source. This is the first time that differences in moth flight behaviour over two patternless floors have been reported. These results suggest that orientation flight behaviour of male moths is affected not only by visual patterns, but also by the reflectance or reflected wavelength spectrum of the floor. [ABSTRACT FROM AUTHOR]

In field, plants are exposed to multiple biological stresses simultaneously; for example, insect damage and pathogenic virus infection. In this study, we constructed a simple tripartite experimental system using tomato plant, their insect pest Bemisia tabaci (whitefly), and infectious tomato mosaic virus (ToMV). In the choice test, whiteflies laid more eggs on uninfected plant than on ToMV-infected plant. Further, whiteflies hatched more and grew better on the uninfected plant. Salicylic acid (SA) accumulated in infected plants, and the expression of genes involved in SA production and SA-related response was significantly induced. These plant responses against ToMV infection were similar to those against whitefly attack or SA-treated plants. To examine the importance of plant endogenous SA for whitefly preference, we repeated the choice test using the NahG transgenic tomato that cannot accumulate SA. Whiteflies did not show oviposition preference between NahG plants with and without ToMV infection or whitefly infestation. Overall, whiteflies prefer healthy plants, and SA accumulation in response to biological stresses is involved in their preference. [ABSTRACT FROM AUTHOR]