By contrast, if the plants and larvae are mature, then a treatment application is debatable. If an infestation is observed after sampling, it is most effective to apply insecticides as soon as possible. To increase the larvae's exposure time to the insecticide, use a burn down herbicide on, mow, or burn down grasses or weeds next to the crop after the application of the insecticide. This will force the surviving larvae into the field while the spray is still on the crop. If the infestation is isolated to the edge of the field, a border treatment is effective.
Foliar insecticides are also useful.
If the field has an infestation history, it may be beneficial to apply an insecticide during the time common stalk borer larvae are hatching. Whether or not this would be profitable, however, cannot be determined since the presence or absence of the insect is not detectable at this stage. Cultural Control Controlling weeds and grasses in and around the field is the most useful preventative measure available. Precise timing is necessary though since burning or mowing these areas at the wrong time could actually increase the movement of larvae into the field. There are two important times when this method is most effective.