Effects of additional nutrients on the physiological parameters of Frankliniella occidentalis (Thysanoptera: Thripidae)

This is the authors' abstract. We don't add key points for this paper.

Frankliniella occidentalis (Pergande) is a typical omnivorous insect with a wide range of hosts. It feeds on the leaves, pollen and nectar of plants, as well as the eggs of spider mites. Here, pine pollen (PP) and Tetranychus urticae Koch eggs were added on kidney bean leaves to examine the effects of additional nutrients on F. occidentalis . The differences in physiological parameters were measured after thrips fed on kidney bean leaves (KL), KL + pine pollen (KL + PP) and KL + T. urticae eggs (KL + TE). The results showed that the trehalose content, glycogen content and trehalase activity in thrips increased at most timepoints when they were fed on KL + PP and KL + TE, and the effects of KL + PP were greater than those of KL + TE. However, the different diets did not affect the glucose content. In addition, both KL + PP and KL + TE increased the vitellogenin (Vg) content in thrips at most timepoints. KL + PP had a greater effect on Vg expression than KL + TE. KL + PP and KL + TE also increased the juvenile hormone (JH) titre and the expression levels of JH signal transduction genes Krüppel‐homologue 1 ( kr‐h1 ) and broad ( br ) in thrips at most timepoints; however, the different diets had no significant effect on the expression of the JH degradation gene Juvenile hormone epoxide hydrolase ( JHEH ) at most timepoints. All these results suggest that the carbohydrate, Vg and JH contents of F. occidentalis are correlated with different diets and that PP promotes the synthesis of these substances and the expression of related genes.