The soluble proteins in Nilaparvata lugens adults and nymphs were analyzed by SDSPAGE electrophoresis. Results showed that there were almost equal number protein bands in all types of adult samples

most bands in different wing or gender samples existed content differences except  female adult-specific protein band. There were four bands significantly higher in long-winged adult samples than in short-winged adult samples; in the comparison of male and female adult samples

it was found that there were two bands higher in males than in females

while other three bands higher in females than in males. The bands in nymph samples were gradually increased with the increase of age

four bands were constantly expressed in each instar period

one more band appeared in 5

th

instar nymph samples

and one band could be detected from the 4

th

instar. In addition

the contents of two bands were found much higher in long wing bud nymphs (9.029

9.563 ng/μL) than those in short wing bud nymphs (5.133

3.111 ng/μL) Last we discussed the relationships among the different bands and wing dimorphism or sex differentiation in insects.