Spatial and temporal distribution patterns of ear-feeding insect damage in pre-harvest corn

The key ear-feeding insects of corn in the southern coastal plain region are the corn earworm, Helicoverpa zea (Boddie), the maize weevil, Sitophilus zeamais Motschulsky, and the brown stink bug, Euschistus servus (Say). The population dynamics of E. servus and S. zeamais were assessed by monitoring the insect populations for 17 and 8 wk respectively pre-harvest in three 1/6-hectare corn fields in 2007 and 2008. Damage from ear-feeding insects, H. zea, E. servus and S. zeamais, were assessed at 4-and 1-wk pre-harvest using 9x9 m grid-sampling of the fields. Five randomly selected ears were examined at each grid point. The temporal changes of E. servus and S. zeamais populations will be presented and discussed in relation to the spatial patterns of ear damage caused by H. zea, E. servus, and S. zeamais. The relationship between both the chewing and piercing-sucking insect feeding and the spatial distribution of aflatoxin contamination of corn will also be discussed.