Distribution pattern of natural enemies of cornsilk fly, Euxesta stigmatias (Diptera: Ulidiidae) in corn field

Euxesta stigmatias is a potential pest of sweet corn and field corn in south Florida. In United States, Florida predominates in fresh market sweet corn production and contributes around 20% of the national sweet corn production. This insect lays its eggs at the tip of corn ear. Later the larval stage becomes the damaging stage, which feeds on corn kernel. The most prevalent control is insecticide. It has been found that the lack of insecticide control of E. stigmatias leads to 90 % damage of corn, reducing the corn yield up to 60%. The fly infestation of >2% renders the corn unmarketable. In total 20% expenditure of sweet corn producers is for pesticide application. However, the use of these insecticides is not an absolute solution to the pest problem owing to their restricted control against adult flies, as larvae remain protected inside the corn ear. Other employed control such, as cultural control and use of transgenic corn have not been successful at commercial level. So, it becomes very important to look for an alternative approach to solve this problem. Orius insidiosus (Say) is a commonly occurring potential predator in the cornfields in south Florida. Various development stages of O. insidiosus predates on E. stigmatias eggs. Besides, some unidentified staphylinid immatures actively feed on E. stigmatias eggs and larvae. In the present research, distribution and behavior of these biocontrol agents feeding on E. stigmatias will be addressed.