Identification Of A Male-Produced Aggregation Pheromone In Frankliniella Intonsa And Thrips Palmi

Frankliniella intonsa and Thrips palmi are polyphagous herbivores and cause economic losses on vegetable, fruit and ornamental crops. In the laboratory we tested the behavioral responses of adult F. intonsa and T. palmi to different odor sources in Y-tube olfactometer. Head-space volatiles released from adult males of F. intonsa and T. palmi were collected using solid-phase microextraction (SPME), and identified by gas chromatography (GC)-mass spectrometry (MS) and different chiral gas chromatography (BGB-176SE and CP-chirasil-Dex CB). All results showed as following:1.Behavioral results showed that both males and females of F. intonsa were attracted to the odors released from conspecific males, providing behavioral evidence for a male-produced aggregation pheromone in this species. Adult males of F. intonsa were attracted to the odor of adult males. The result showed that it coule attract both sexs.2.GC-MS analysis of odors collected on SPME fibers showed that two major components in head-space volatiles produced by male F. intonsa, which are not in the female odor. The compounds were not present in hexane extracts of males.3. GC-MS analysis showed that two major components in head-space volatiles produced by F. intonsa were (R)-lavandulyl acetate and neryl (S)-2-methylbutanoate, which are the same compounds that are reported in volatiles of Frankliniella occidentalis males. However, quantificational analysis showed that the ratio of (R)-lavandulyl acetate and neryl (S)-2-methylbutanoate differed between F. intonsa and F. occidentalis. Behavioral experiments further showed that the difference in ratio of the two components plays an important role in interspecies identification between F. intonsa and F. occidentalis.4. Females of T. palmi were attracted to the odors of adult males of T. palmi, but not to the odor of adult females of T. palmi. The results showed that males were producing aggregation pheromone in this species. GC-MS analysis showed that two major components in head-space volatiles produced by T. palmi, which are not in the female odor. The compounds were not present in hexane extracts of males which showed that the compounds are produced on demand and not stored.