1. ______ larvae found          X  ______ expected survivorshipa,b          =  ______ surviving larvae
2. ______ surviving larvae      /  ______ plants examined                   =  ______ larvae per plant
3. ______ larvae per plant      X  ______ yield loss per larvaa,c           =  ______ yield loss
4. ______ yield loss            X  ______ expected yield (bushels per acre) =  ______ bushels loss per acre
5. ______ bushels loss per acre X  ______ price per bushel                  = $______ loss per acre
6. ______ loss per acre         X  ______ percent controla                  = $______ preventable loss/acre
7. ______ preventable loss/acre -  ______ cost of control per acre          = $______ profit (loss) per acre

^aAll percents must be written using decimals (i.e., 50 percent = 0.5). ^bExpected survivorship usually is 0.2 to 0.5 (20 to 50 percent), depending on the instars and degree of environmental stress on the larvae before they bore into the plant. ^cUse 0.059 for 10-leaf corn, or 0.05 for 16-leaf, whorl-stage corn.

Need an example?

Download as PDF (35KB)