Abstract:  The type, number, distribution and ultra-morphology of antennal sensilla of both genders in three Frankliniella thrips, i. e., Frankliniella intonsa (Trybom), F. tenuicornis (Uzel) and F. occidentalis (Pergande), which are serious agricultural pests in China, were observed and compared using scanning electron microscopy. Through the morphological observation and comparison, we hope to clarify the differences of sensilla among these species, supplement the detail information of thrips sensilla and perfect the researches on thrips morphology. The results showed that there are eight types of sensilla on the antenna of every species, i. e., Böhm bristles, sensilla campaniformia, sensilla trichodea, sensilla chaetica, sensilla basiconica, sensilla coeloconica, sensilla cavity and unusual sensillum. The number and distribution of sensilla are uneven on each antennal segment. The analysis results revealed that every type of sensilla has a relatively stable distribution pattern, and there is no significant difference among closely-related species or between sexes.

Key words: Frankliniella intonsa, Frankliniella tenuicornis, Frankliniella occidentalis, antenna, sensilla, ultrastructure, scanning electron microscope (SEM)