By Blake Jackson
Managing belowground insect pests can be difficult, particularly in corn production systems. In Pennsylvania, these pests are less common in crops like soybeans, small grains, or hay, but they can become a recurring issue in corn, especially when it is grown continuously in the same fields.
According to Penn State Extension experts, pest pressure is often inconsistent in rotated systems, with some fields affected regularly while others remain problem-free.
Typical symptoms include missing plants, stunted growth, or wilting seedlings. The most reliable way to confirm pest activity is by digging up affected plants and inspecting roots for feeding damage.
Crop rotation remains one of the most effective strategies for reducing pest populations. Longer rotations introduce a variety of crops over time, disrupting pest life cycles and limiting their ability to establish. In contrast, continuous planting of the same crop allows pests to thrive due to a steady food source.
When infestations occur, soil- or seed-applied insecticides can provide control, but only if the pest species is correctly identified. Weather conditions also play a role, as excessive moisture can reduce the effectiveness of certain insecticides.
Seedcorn maggots are a concern in tilled fields, where they feed on seeds and underground stems, especially in soils rich in decaying organic matter.
Wireworms, the larvae of click beetles, can persist for years and damage roots and stems, particularly in fields previously planted with grass or forage crops.
White grubs, which include several scarab beetle species, also feed on roots and are more likely to appear in fields following pasture or hay.
Slugs, although not insects, are significant pests in no-till systems, feeding on seeds and seedlings during cool, wet conditions. Finally, western corn rootworm is one of the most damaging corn pests, particularly in continuous corn systems, where larvae feed on roots and can lead to plant lodging and major yield losses.
FAQs
- What are belowground pests?
They are insects or organisms that attack plant roots and seeds underground.
- Why is corn more affected than other crops?
Corn, especially continuous corn, provides a consistent food source for pests.
- How can farmers detect these pests?
By digging up damaged plants and checking roots for feeding injury.
- Does crop rotation help control pests?
Yes, it disrupts pest life cycles and reduces population buildup.
- What is the most damaging corn pest?
Western corn rootworm is considered the most destructive pest in corn.
Photo Credit: gettyimages-oticki
Categories: Pennsylvania, Crops, Corn