Does Trichogramma ostriniae have potential for controlling western bean cutworm in the field?
Western bean cutworm (WBC) is a pest of field corn, sweet corn, and dry beans that first arrived in NY in 2009 from its historic range in the western high plains. In the intervening years, it has increased to economically damaging levels. Organic growers of the three host crops need effective options for managing it.
Trichogramma ostriniae (Tost), a commercially available egg parasitoid most commonly released to control European corn borer, had previously been shown to parasitize WBC egg masses in the lab. We wanted to know if Tost would parasitize WBC in the field and reduce crop damage.
Key accomplishments, knowledge generated, outreach activities, resources created
- We released Tost in organic sweet corn, field corn, and dry bean fields at a rate of 90,000 per acre. Releases started the week after moths were first caught in pheromone traps through the week after peak flight. We collected egg masses in sweet corn fields to estimate percent parasitism. In field corn and dry beans we surveyed damage in release and non-release areas.
- Of 55 egg masses collected from sweet corn fields, an average of 70% were parasitized, with 74% of eggs within an egg mass parasitized.
- In field corn, WBC damage levels were not different between release and non release areas. In dry beans, infestation levels in the were too low to compare damage in release and non-release areas. We didn’t collect egg masses in either field corn or dry beans.
- Egg masses collected from release areas in field corn in 2018 showed some parasitism. This will be explored more thoroughly 2019.
- Additional study is needed to assess the potential for Tost to control WBC in these crops.
NESARE funded Project ONE16-271
Abby Seaman, NYS IPM Program
Jeffrey Gardner and Mike Hoffmann, Department of Entomology
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2016 - present