Abstract: 【Aim】Brochosomes, which are nano particles covering on the body surface of the adults of the tea green leafhopper, Empoasca onukii, can avoid the stickness of their own sticky exudates and the permeability of insecticide droplets. In this study, we tried to explore the methods to damage the brochsomal protedion layer, to analyze the rhythm of brochosome secretion and the repairing behaviors of E. onukii adults after damage to the brochosomal protection layer, and to observe the micromorphology of the brochosome-anointing organ, so as to clarify the specific characteristics of repairing the nano-sized brochosomal protection layer of E. onukii adults.【Methods】 E. onukii adults were treated with water spraying, powder injection and a high-humidity condition, and insecticide spraying (0.05 mg/L bifenthrin) with different surfactants (0.2% detergent, 0.5% Tween-80, and 0.05% organosilicon adjuvant Silwet 618). The damage effects of these treatments on the brochosomal integument of adults were observed by the indicator-plaque method and scanning electron microscope (SEM). The adults were sprayed and the single wing was smeared with organosilicon adjuvant (Silwet 618) solution as damaged treatments, with untreated adults as the control. The frequency of white brocosomal spots was recorded by a pohotographic microscopy and the rhythm of brochosome secretion was analyzed by the frequencies of white brochosomal spots. The brochosome-anointing behaviors were analyzed by the Vegas software. The location of the brochosome-anointing organ was verified by the organ-ablated method, and the microstructures were observed by SEM. 【Results】The brochosomal protection layer of E. onukii adults was not damaged by the treatments with water spraying, powder injection and a high humidity condition, while obvious plaques on the adult wings were caused by the spraying with insecticide plus organosilicon adjuvant (Silwet 618) solution. The SEM images showed that brochosomes were agglomerated with residual adjuvants and fell off. The interval time of brochosome secretion in the organosilicon adjuvant Silwet-sprayed adults was (22.3±1.8) h, which was about 8.0 h shorter than that in the control. Within 5 d post spraying, the frequency of brochosome secretion in the organosilicon adjuvant Silwet-sprayed adults was (8±1) times, which was about 3 times more than that in the control. The vibration frequeny of the forelegs and hindlegs of adults could reach (16.7±2.4) Hz. After the delicate setae row on the ventral side of hindleg tibia was treated with the organablated method, the adults were unable to anoint the brochosomes normally, which might be due to the reverse bending of the hooked apices of delicate setae.【Conclusion】 The organosilicon adjuvant Silwet 618 can damage the brochosomal protection layer on the body surface of E. onukii adults. The adults of E. onukii repair the brochosomal layer by shortening the interval time of brochosome secretion after organosilicon adjuvant treatment. The moving rate of foreleg and hindleg and the normally-hooked apices of the tibia are the key factors to anoint the nano-sized brochosomes in E. onukii adults.

Key words: Empoasca onukii, body surface, brochosome, organosilicon adjuvant, brochosome secretion, brochosome-anointing organ