Objective The study was conducted to analyze the spatial distribution of Spodoptera frugiperda(J. E. Smith) larvae in corn fields of Hainan Province.

Method Six aggregation indexes, Taylor power law and Iwao m*-m regression method were used to analyze the spatial distribution of S. frugiperda larvae in three stages: low age(1st-2nd instar), middle age(3rd-4th instar)and old age(5th-6th instar) in Hainan Island.

Result The spatial distribution of S. frugiperda larvae was mainly related to corn planting system, larval instar and climate in Hainan. It was damaged seriously in seedling stage, small bell stage and big bell stage. The proportion of 3rd instar larvae was the highest, and they were distributed in aggregation. The 5th-6th instar larvae distributed evenly in flowering and mature stages. From the perspective of regional distribution, the S. frugiperda larvae were concentrated and distributed in the eastern and central parts of Hainan Province, and evenly distributed in the southern and northern parts(I>0, C>1, K>0, Cα>0, m*/m>1, α>0, β>1, lg α>1, b>1). The data of each field were analyzed according to Taylor power law lg v=0.23663+1.24689 lg m(R=0.9437)and linear regression equation m*=-0.07870+2.16842m(R=0.7777), and it could be concluded that the pests in each area of Hainan showed an aggregated distribution and the aggregation degree was not dependent on the population density.

Conclusion The research result will provide references for the investigation of population density and selection of appropriate period of pest control.