Variability and stability of tea weevil‐induced volatile emissions from tea plants with different weevil densities, photoperiod and infestation duration

Abstract

After herbivore attack, many plants emit herbivore-induced plant volatiles (HIPVs). HIPVs can attract carnivores and/or repel herbivores, thereby mediating tritrophic plant-herbivore-carnivore interactions. HIPVs act as chemical information between organisms; hence, their variability and stability are vital. In the present study, variations in the volatile emissions, from the tea plant Camellia sinensis (O. Ktze) damaged by the tea weevil Myllocerinus aurolineatus (Voss) (Coleoptera: Curculionidae), with weevil densities, photoperiod and infestation duration, were investigated. The volatiles induced by high-density weevils were more abundant in composition and amount than those induced by low-density weevils, whether at noon, night or after weevil removal. The induced volatile emissions were similar on the second and third day after infestation, and the emissions of the major induced compounds displayed diurnal cycles. Linalool, (E,E)-α-farnesene, and benzyl nitrile were emitted mainly at noon, whereas 1,3,8-p-menthatriene and (E)-β-ocimene were maximally emitted at night. Given the different emission dynamics, significant differences were found between noon-and night-induced volatiles. In summary, tea plants damaged by different weevil densities emitted a relatively stable signal at a particular time. This stability could be attributed to the similarities under the two densities of the main induced volatile compounds, their relative ratios and the emission dynamics of the induced volatiles.

Three odorant binding proteins may regulate the behavioural response of Chrysopa pallens to plant volatiles and the aphid alarm pheromone (E)‐β‐farnesene

“…To confirm the functions suggested by the phylogenetic tree and tissue expression profiles, the binding affinities of the five CpalOBPs to 87 volatiles from tea plant (Cai et al ., ), cotton (Yu et al ., ), maize (De Moraes et al ., ; Itoh et al ., ; Carroll et al ., ), tobacco (De Moraes et al ., ; Yan et al ., ), faba bean (Webster et al ., ) and the aphid alarm pheromone (E)‐ß‐farnesene (Bowers et al ., ) were determined using a fluorescent binding assay. Overall, 31 compounds had high binding affinities (Ki < 20 µM) to at least one of the five CpalOBPs.…”

Attractiveness of host volatiles combined with background visual cues to the tea leafhopper, Empoasca vitis

“…In the field, tea plants under various biotic and abiotic stresses, such as insect infestations (Cai et al, 2012(Cai et al, , 2014, might emit large amounts of compound-rich volatile blends. Thus, E. vitis adults encounter lure traps in a highly complex odorant world in tea plantations.…”

Volatiles from non‐host aromatic plants repel tea green leafhopper Empoasca vitis

“…Volatile samples were analyzed following the method of Sun et al (2010) and Cai et al (2012) with several modifications. Eluted samples were analyzed by gas chromatography and mass spectroscopy (GC-MS) using a QP 2010 (Shimadzu, Kyoto, Japan) gas chromatograph equipped with a DB-5 MS capillary column (60 m length, 0.25 mm internal diameter, 0.25 lm film thickness; J&W Scientific, Folsom, CA, USA).…”