Maize (corn) is one of the most important staple crops around the world, particularly in regions like Sub-Saharan Africa and South America. Unfortunately, maize crops are highly susceptible to various insect pests that can cause significant yield losses if not properly managed.

This blog focuses on some of the most common insect pests of maize and recommends the best insecticides to control them, thereby creating favourable conditions for maize growth and providing insight into how farmers can protect their crops.

1. Fall Armyworm

The fall armyworm is a notorious pest that has spread rapidly across maize-growing regions worldwide. This pest is highly destructive, especially in its larval stage, when it feeds on the leaves, stems, and even the ears of maize plants. If not controlled, it can devastate entire fields.

Control Measures:

1. Early Detection: Regular scouting of maize fields for early signs of damage can help control the infestation.
2. Biological Control: Natural predators like parasitic wasps and fungi can be introduced to curb the spread.
3. Insecticide Solution Control: Insecticides containing active ingredients like Acetamiprid or Emamectin Benzoate (like Hallakat or Kare from Saro Agrosciences) can be effective if applied early (i.e., at the onset of infestation).

2. Stem Borers
Stem borers are another major pest of maize. These insects lay eggs on the plant, and the larvae bore into the stem, feeding on the internal tissues. This weakens the plant and reduces its ability to absorb nutrients and water, leading to poor growth and lower yields.

Control Measures:

1. Cultural Practices: Crop rotation and intercropping with non-host crops can disrupt the lifecycle of stem borers.
2. Use of Resistant Varieties: Some maize varieties are bred to resist stem borer attacks.
3. Insecticide Solution Control: Insecticides with active ingredients such as Cypermethrin (e.g., Cypertex) or Lambda-cyhalothrin (e.g., Kombat) can be applied to reduce the infestation. Whichever of the options selected should be applied at the onset of insect infestation for best results.

3. Maize Weevil

The maize weevil is a storage pest that attacks harvested maize grains. Adult weevils bore into the grains and lay eggs, causing damage that results in weight loss, reduced quality, and economic loss.

Control Measures:

1. Proper Storage: Use airtight containers or silos to store maize and prevent weevil infestation.
2. Fumigation: Treating storage areas with fumigants like Phosphine can help control weevils.
3. Insecticide Solution Control: Storage products like Spintordust containing Spinosad can be effective in controlling maize weevils.

4. Aphids

Aphids are small, sap-sucking insects that attack the leaves and stems of maize plants. They weaken the plant by reducing its photosynthetic ability and are known to spread viral diseases like maize dwarf mosaic virus.

Control Measures:

1. Encourage Natural Predators: Ladybugs and lacewings naturally feed on aphids and can help control their population.
2. Use of Resistant Varieties: Planting aphid-resistant maize varieties can reduce the risk of infestation.
3. Insecticide Solution Control: Insecticides containing active ingredients like Acetamiprid or Emamectin Benzoate (like Hallakat from Saro Agrosciences) can be effective if applied early (i.e., at the onset of infestation). A repeat application may be required after 2 weeks if the infestation reoccurs.

5. Leafhoppers

Leafhoppers feed on maize plants by sucking sap from the leaves. This feeding can cause leaf curling, yellowing, and reduced photosynthesis. Leafhoppers can also transmit plant diseases like maize stunt.

Control Measures:

1. Cultural Practices: Maintain good field hygiene and remove weeds that can harbour leafhoppers.
2. Natural Predators: Encourage the presence of predators such as spiders and predatory beetles.
3. Insecticide Solution Control: Insecticides with Acetamiprid (e.g., Hallakat) or Imidacloprid (e.g., Termex or Solitex) active ingredients are potent options for controlling leafhoppers without harming the maize. Make sure to apply at the onset of infestation and follow the recommended dose rates for best results.

Effective pest management in maize production requires a combination of preventive, cultural, biological, and insecticide solution control measures. Early detection and timely intervention are crucial to minimising the damage caused by these pests. By adopting integrated pest management (IPM) strategies, farmers can protect their maize crops from these common insect pests and ensure a healthy, high-yielding harvest.

Always remember, prevention is better than cure – regular field scouting, crop rotation, and using resistant varieties are key practices that can help safeguard your maize against insect pest attacks.