Scouting time
Fields can be sampled before maturity for the presence of stem borer tunneling and live larvae by carefully splitting stems from several locations throughout the field.
Sampling method
Dead, wilted and drying leaves above the normal senescence zone at the bottom of the plant can help identify stem borer infestations. Bored stalks reveal reddish interior discoloration when split.
Fields can be sampled before maturity for the presence of stem borer tunneling and live larvae by carefully splitting stems from several locations throughout the field. Fields with high percentages of infested stems should be harvested as soon as possible to avoid girdling and lodging. Recent research has revealed that the onset of girdling is associated with stalk desiccation, so timely harvest is especially important under conditions of low soil moisture.
Thresholds
None listed at this time.
Chemical control
Since adult beetles emerge over several weeks and remain active for up to two months, control with foliar insecticides is not feasible and timely harvest is the best tactic for averting losses.
Non-chemical controls
No resistant varieties exist at this time.
Content authors
Disclaimers
This information comes from the Kansas State University Agricultural Experiment Station and Cooperative Extension Service publication MF743. Information may not be suitable for states other than Kansas.
