How to Manage Insect Pests in Maize: Damaging Symptoms, Treatment, Prevention, and Control

Welcome to our comprehensive guide on managing insect pests in maize! Maize, also known as corn, is a staple crop in many regions but is prone to attack by various insect pests. This article will delve into the damaging symptoms caused by these pests, explore effective prevention strategies, and discuss control methods that can safeguard your maize crops. Whether you’re a seasoned farmer or a gardening enthusiast, this resource will equip you with the knowledge and techniques to combat insect pests and ensure the health and productivity of your maize plants.

How to Manage Insect Pests in Maize

Major and Common Insect Pests of Maize and Their Management

  1. Fall Armyworm (Spodoptera frugiperda): This voracious pest can cause extensive damage by feeding maize plants’ leaves, tassels, and ears. Integrated Pest Management (IPM) practices involving early detection, cultural control, and targeted insecticide application are essential for effective management.
  2. Corn Earworm (Helicoverpa zea): These pests primarily target maize ears, damaging and contaminating kernels. Key management tactics are implementing pheromone traps, employing biological controls such as parasitic wasps, and timely insecticide applications.
  3. European Corn Borer (Ostrinia nubilalis): Larvae of this pest bore into maize stems, leading to weakened plants and yield losses. Planting Bt (Bacillus thuringiensis) maize varieties and practicing crop rotation can help control infestations.
  4. Maize Weevil (Sitophilus zeamais): This stored grain pest can cause significant post-harvest losses. Proper grain storage techniques, such as cleaning and drying maize, and airtight storage options can help prevent infestations.
  5. Aphids (Aphidoidea): These small, sap-sucking insects can transmit viral diseases and stunt maize growth. Encouraging natural enemies like ladybugs, practicing regular scouting, and applying appropriate insecticides can effectively manage aphids.
  6. Wireworms (Agriotes spp.): The larvae of these pests feed on maize seeds and roots, leading to poor germination and stand establishment. Crop rotation, deep plowing, and treated seeds can mitigate wireworm infestations.
  7. Stalk Borers (Papaipema nebris): These pests tunnel inside maize stalks, causing lodging and plant death. Cultural practices like removing crop residues and cultivating resistant hybrids aid in managing stalk borers.
  8. Cutworms (Noctuidae family): These nocturnal caterpillars cut maize seedlings at ground level, causing stand losses. Using cutworm collars, implementing biological controls like nematodes, and practicing early planting can minimize damage.
  9. Leafhoppers (Cicadellidae family): Leafhoppers transmit phytoplasma diseases, leading to stunted growth and reduced yields in maize plants. Planting disease-resistant varieties and managing weeds can help control leafhopper populations.
  10. Armyworms (Mythimna spp.): These caterpillars feed on maize leaves, leading to defoliation. Regular monitoring, practicing crop rotation, and employing biological controls like parasitic wasps can aid in managing armyworm.

How to Manage Insect Pests in Maize

Spotted Stem Borer Pest Management in Maize 

  • Identification: The maize pest Spotted Stem Borer (Chilo partellus) reduces yields by 26% to 80%. The larvae are creamy pink to yellowish brown with four rows of dotted stripes on the back and a reddish head. The mature female moth has brown-yellow forewings and white hind wings. Life lasts 5-6 weeks. 
  • Damage: Spotted Stem Borer moths deposit eggs on 3-5 leaf maize plants and eat in groups, leaving pinholes and papery windows as the whorl unfurls. As the infestation proceeds, larvae tunnel into the developing stalk, reaching the meristem and drying out the leaf whorl, known as “dead heart,” causing plant death and probable tiller production. 
  • Management: To control Spotted Stem Borer, collect and dismantle stubbles, sow Napier grass as a trap crop, intercrop maize with cowpea, and release two Trichogramma chilonis egg parasitoids. Management: Discard dead hearts. When infestation surpasses 10%, apply 150ml/ha Chlorantraniliprole 18.5 SC. Trichogramma chilonis, Cotesia flavipes, Chrysoperla carnea, coccinellids, spiders, and other beneficial insects can also suppress Spotted Stem Borers.

Pink Stem Borer Pest Management in Maize 

  • Identification: Pink stem