Sweet Corn (Pennsylvania)
Coordinated by Shelby Fleisher (sjf4@psu.edu), Professor of Entomology, Penn State University


Sweet corn is a cornerstone for diversified, fresh-market, direct-retail farms that exist throughout the mid-Atlantic and northeastern US. In Pennsylvania alone, with 48,622 acres in vegetables, we estimate >4,000 diversified fresh-market farms, and sweet corn production on 15,400 acres valued at $35.5 million in 2009. Nationally, 28,421,000 cwt was produced for fresh-market, and 3,234 short tons for processing, in 2009 (USDA NASS). 

Sweet Corn
Sweet Corn (Zea mays convar. saccharata). Source: Pixabay


PestWatch is a web-mapping platform focused on tracking lepidopterans for IPM in sweet corn and diversified vegetables. Unfortunately, however, PestWatch lacks key structural elements. The broad goal of this Crop Pest Program is to advance this infrastructure through seamless integration with iPIPE. Advancement is anticipated in:

  • Human infrastructure, communication, and IT training 
  • Data merging: iPIPE and PestWatch data seamlessly integrated 
  • Batch uploading and user-driven reporting functionality
  • Data quality
  • Data storage and long-term access
  • Mobile app for data entry and visualization


IPM in sweet corn prioritizes efforts to produce a high-quality ear. Several migratory lepidopterans can infest the ear. Corn earworm presents the primary risk. Eggs are laid individually on silks, and larvae rapidly move into the ear tip. There is very little (<5%) tolerance for insect damage or presence for the fresh-market crop. Crop destined for processing can tolerate slightly higher damage rates. To achieve marketable crops, growers apply insecticides during the tassel and silking growth stages. Spray frequency, materials, and rates are influenced by pest pressure estimated through pheromone trap captures. Alternatives to foliar insecticides exist, but can be difficult for growers to adopt. These include Bt-cultivars (presents market risk or rejection) or hand-applied horticultural oil to silk tubes (presents problems for labor availability and cost).

Important Pests

Migratory lepidopterans: corn earworm and fall armyworm

Corn earworm
Corn earworm  Helicoverpa zea (Boddie)
L. Croissant
, Bugwood.org

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