Due to high levels of black cutworms during the 2012 growing season, many corn producers are concerned about another black cutworm outbreak in 2013, says Matt Hubsch, senior agronomist, Legend Seeds.
"Here are my thoughts on this; black cutworm outbreaks don't happen on a regular or yearly basis in the upper Midwest. The pests thrive in areas like Texas and Mexico and cannot overwinter in our region of North America. Thus, there are several factors that need to be in place in order for states such as Iowa, South Dakota or Wisconsin to see an outbreak," Hubsch said.
First, Hubsch says weather conditions have to be just right.
"Very strong southern prevailing winds are needed to carry the moths northward into our regions," he said.
Secondly, he adds this would need to occur quite early in the spring in order for significant damage to take place, as the timeframe between VE and V4 growth stages is when this pest is most destructive. (After the V4 stage, as the plant physiologically matures and the stalk widens, the cutworm cannot inflict sizeable damage.)
"So, although the black cutworm is not consistently a factor, it is a pest to be considered. And I suggest that corn producers implement a management system to reduce or eliminate cutworm damage in the event we were to see a strong migration like we did in 2012," Hubsch said.
To control black cutworms, Hubsch suggests growers utilize traits such as Agrisure Viptera, or hybrids containing the Herculex corn traits, which include Genuity Smartstax. On acres where these traits are not present, he says growers should implement some very simple management practices that will eliminate or reduce losses from black cutworms or any other cutworms.
Black cutworm moths are attracted to green vegetative growth in early spring - and this is where they'll deposit their egg masses.
"Last spring's warm March and April allowed for some very early weed growth in our fields, which was highly attractive to these moths. The growers that experienced sizeable losses were those that either no-tilled into these fields or planted immediately after working them," he said.
The following is a simple recommendation Hubsch says can be followed on a yearly basis to aid in black cutworm damage prevention:
Black cutworm damage prevention practices:
- No-Till: If weeds are present; spray to control weeds and wait for a minimum of one week before planting corn. This will allow any cutworm larvae to starve and die before corn is planted.
- Tillage: If weeds are present; till field black and wait for a minimum of one week before planting corn. This will allow any cutworm larvae to starve and die before corn is planted.
Note: Spraying off or tilling down alfalfa in the spring should also be done within the previously described guidelines.
Hubsch adds that if growers have winter cereals such as winter wheat or rye in their rotation, they should consider the fact that if a significant number of volunteer plants are present, they could attract the moths to fields in the spring.
"A week time lapse between tillage or spraying to allow larvae to starve and die is highly recommended for eliminating or reducing damage," he said.
Lastly, Hubsch adds that it is important to note that black cutworm moths are not the only cutworm moths attracted to green vegetative weed growth in the spring. And there are other preventative measures that can be taken to reduce losses from any of the cutworms, but this is probably the easiest and simplest recommendation that can be practiced on a yearly basis.