Occurrence Characteristics and Control of Thrips tabaci in Yanji City

With the increasing plant area of welsh onion, onion and Chinese onion, the damage of Thrips tabaci in Yanji City is aggravating day by day. Through preliminary investigation and literature reading, we summarized occurrence status, morphological characteristics, damage characteristics, occurrence regularity, living habit, outbreak cause and integrated control technology of T. tabaci in Yanji City, in order to control the hazard of T. tabaci effectively.

Effects of single and dual species herbivory on the behavioral responses of three thrips species to cotton seedlings

This study investigated the olfactory responses of 3 thrips species [Frankliniella schultzei Trybom, E occidentalis Pergrande and Thrips tabaci Lindeman （Thysanoptera： Thripidae）] to cotton seedlings [Gossypium hirsutum L. （Malvales： Malvaceae）] simulta- neously damaged by different combinations of herbivores. Cotton seedlings were damaged by foliar feeding Tetranychus urticae Koch （Trombidiforms： Tetranychidae）, Helicoverpa armigera Hibner （Lepidoptera： Noctuidae）, Aphis＇ gossypii Glover （Hemiptera： Aphidi- dae） or root feeding Tenebrio molitor L. （Coleoptera： Tenebrionidae）. Thrips responses to plants simultaneously damaged by 2 species of herbivore were additive and equivalent to the sum of the responses of thrips to plants damaged by single herbivore species feeding alone. For example, E occidentalis was attracted to T. urticae damaged plants but more attracted to undamaged plants than to plants damaged by H. armigera. Plants simultane- ously damaged by low densities of T. urticae and H. armigera repelled E occidentalis but as T. urticae density increased relative to H. armigera density, E occidentalis attraction to coinfested plants increased proportionally. Thrips tabaci did not discriminate between un- damaged plants and plants damaged by H. armigera but were attracted to plants damaged by T. urticae alone or simultaneously damaged by T. urticae and H. armigera. Olfactometer assays showed that simultaneous feeding by 2 herbivores on a plant can affect predator- prey interactions. Attraction of F. occidentalis to plants damaged by its T. urticae prey was reduced when the plant was simultaneously damaged by H. armigera, T. molitor, or A. gossypii and F. schultzei was more attracted to plants simultaneously damaged by T. urticae and H. armigera than to plants damaged by T. urticae alone. We conclude that plant responses to feeding by I species of herbivore are affected by responses to feeding by other herbivores. These plant-mediated interactions between herbivore complexes af- fect the behavioral responses ofthrips which vary between species and are highly context dependent.