How to Manage Stem Borers in Soybeans

FBN Network

Sep 27, 2023

Stem Borers, also known as stalk borers, are destructive insects that bore into the stems of soybean plants, causing plant wilting, stunting and even death. 

However, by employing preventative scouting strategies and taking quick action with chemical treatments like Willowood Lambda-Cy 1EC and GCS Bifenthrin 2EC, farmers can control Stem Borers and maintain yield potential. 

This post will outline: 

  • How Stem Borers affects crops 

  • How to identify Stem Borers

  • Regions typically affected by Stem Borers 

  • How to manage Stem Borers

  • Chemical products to control Stem Borers 

How Do Stem Borers Affect Soybeans? 

Stem Borers lay their eggs on the leaves or stems of the plants, and once the larvae hatch, they tunnel into the stem, feeding on the plant tissues. This feeding activity weakens the stems, making them more susceptible to lodging and breakage. Stem Borers can also introduce secondary infections, such as fungal diseases, further exacerbating the damage. 

While Stem Borers can infest soybeans at various stages of their growth, they are most commonly found in the early to mid-season stages. It is during this critical period that the pests lay their eggs on soybean plant leaves or stems. After hatching, tiny larvae bore into the stems, where they feed and develop, causing significant crop damage. 

How to Identify Stem Borers

Identifying Stem Borers in soybeans can be a difficult task, as these pests tend to spend the majority of their lifecycle hidden inside the stems of the plants. However, there are several key indicators that can help to identify their presence. 

  • Entry Points and Frass: Pay close attention to the stems of soybean plants and look for small holes or entry points, which are often accompanied by the presence of frass or sawdust-like material. These signs can be a strong indication of a Stem Borer infestation.

  • Wilting and Yellowing: Be on the lookout for any wilting or yellowing of the leaves, as well as stunted plant growth. These symptoms can be attributed to the damage caused by Stem Borers, as they disrupt the normal flow of nutrients and water within the plant. 

  • Susceptibility to Breakage: Watch for the susceptibility of the plants to break easily at the base, which can be a result of the weakening of the stem caused by Stem Borer feeding activity.

  • Adult Moths: The presence of adult moths flying around the field, especially during the evening hours, indicate the potential threat of Stem Borers.

  • Neighboring Fields: Observe neighboring fields with infestations. If nearby fields are struggling with Stem Borers, be vigilant and take proactive, preventive measures to protect your fields. 

Regions Affected by Stem Borers

Stem Borers are a common pest in soybean-growing regions worldwide, but they are particularly prevalent in areas with warm climates and high humidity. Regions such as the southern United States, South America, Africa, and parts of Asia are especially susceptible to infestations. 

How to Manage Stem Borers

To effectively manage Stem Borers, it is crucial to implement proactive measures.

Regular field scouting is essential to detect early signs of infestation, such as wilting or entry holes in the stems. If any infested plants are observed, it is recommended to remove and destroy them to prevent the spread of the pests.

Additionally, implementing cultural practices such as crop rotation, intercropping, and maintaining proper plant spacing can help reduce the risk of infestation. 

How to Chemically Manage Stem Borer 

When deciding whether to employ chemical products to control Stem Borers in soybeans, farmers should first assess the severity of the infestation and determine the economic threshold for treatment. Once fields have reached a level of infestation at which chemical products are needed: 

  • One popular option is Willowood Lambda-Cy 1EC, an insecticide containing lambda-cyhalothrin

  • Another option is GCS Bifenthrin 2EC**, which is another insecticide containing bifenthrin with similar label applications.

Consider integrating other management practices alongside chemical control, such as crop rotation, biological control, and pheromone traps, to enhance effectiveness and reduce reliance on insecticides. Rotating between different modes of action helps prevent the development of resistance in stem borer populations, ensuring long-term sustainable pest management.

Stem Borer Crop Protection from FBN Direct®

Proactively scouting for and responding to pest presence in your fields will help reduce potential crop damage and improve yield. FBN Direct has a wide variety of effective insecticides to help address pest pressures and keep your operation on track. With transparent pricing, straightforward online ordering, detailed product labels and fast direct-to-farm delivery, FBN Direct can help you get the products you need to protect your crops. 

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FBN Network

Sep 27, 2023

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