Spodoptera litura (Splt)and Spodoptera exigua (Se) are both extremely serious agricultural lepidopteran pests and belong to the same family (Noctuidae) and the same genera (Spodoptera). 

Splt

nucleopolyhedrovirus (

Splt

NPV) and Se multiple nucleopolyhedrovirus (

Se

MNPV) are viral pathogens to the two insects

respectively. Comparative analysis of the complete genome sequences of SpltNPV and SeMNPV show two genomes are very similar. Although both the pathogens and the hosts are closely related

the mechanism of the two baculovirus not infecting the hosts each other is unclear. This study concentrate on investigating the reason of the Se301 cells by

Splt

NPV abortion infection. The replication of virus have completed in 

Splt

NPVinfected Se301 cells by testing with dot blotting. The results of RT-PCR analysis displayed that all genes from very early genes to late genes have transcribed in the infected cells. Western blotting analysis revealed that it is no specific POLYHEDRIN with a size of 29 700 when using the POLYHEDRIN antiserum. Collectively

in the Se301 cells infected by 

Splt

NPV

the replication of virus and the transcription of all late genes have happened

although it is not detected the expression of very late genes

suggesting that the blocking of 

Splt

NPV proteins expression is the main limited factors in viral replication cycle.