Fruit Borer in Cotton

Fruit borers are damage-causing pests that attack cotton bolls, causing significant damage and reducing yields. Signs of fruit borer in cotton include small holes in bolls, wilting leaves, and reduced boll set. This blog provides prevention and control methods including crop rotation, biological control, and chemical applications. 

What is Fruit Borer?

The Fruit Borer is also called the American bollworm (Helicoverpa armigera), one of the most destructive pests of cotton worldwide. It's also known as the corn earworm, tomato fruitworm, and tobacco budworm, as it attacks a wide range of crops.Caterpillars feed on leaves, buds, growing points, flowers and fruit. It can thus occur in the vegetative or plant growth stage as well as at the flowering and fruiting or seed set stages. The resulting leaf damage reduces the leaf area that can photosynthesise plant nutrients and can result in high losses of grain production if not controlled.

• The larvae bore into squares, flowers, and bolls, causing them to shed or develop poorly.
• Infected bolls will have round holes.
• A single larva can damage up to 40 bolls.

Short description of fruit borer in cotton:

Life cycle of BollWorm:

• Adult moths lay eggs singly on leaves, squares, and bolls.
• The eggs hatch into caterpillars (larvae) that feed on the plant tissue.
• The larvae pupate in the soil.
• Adults emerge from the pupae and mate to start the cycle again.

Favorable factors for bollworm in cotton:

Warm temperatures: Bollworms have an optimal temperature range for development and activity, typically between 24°C and 32°C (75°F and 90°F). Hot summers with minimal temperature fluctuations create ideal conditions for rapid bollworm growth and multiple generations per season.

Humid weather: Moderate humidity levels (around 60-75%) help bollworms survive and lay eggs effectively. Dry periods can hinder their development and reproduction, but periods of heavy rain can also wash away eggs and larvae, offering some natural control.

Limited rainfall: While moderate rainfall can be beneficial for cotton growth, prolonged periods of heavy rain can damage flowers and bolls, providing alternative food sources for bollworms and potentially increasing their populations.

Initial Symptoms of bollworm in cotton:

• Tiny holes on leaves: First and second instar larvae of both bollworm species feed on tender leaves, creating small, irregular holes. These initial signs might be subtle, but scouting for them is crucial for early detection.
• Discolored or wilted flowers: Infested flowers might appear discolored or wilted due to feeding damage by bollworm larvae.

Severe Symptoms of bollworms in cotton:

• Large holes in bolls: As larvae grow, they bore large holes into bolls, feeding on the developing seeds and lint. Infested bolls often have significant frass accumulation around the entry points.
• Stunted bolls and poor seed development: Severely infested bolls may stop growing and appear stunted. Seed development within such bolls is often compromised, leading to reduced yield and quality.

Control measures of Fruit Borer in Cotton:

Controlling fruit borer (cotton bollworm, Helicoverpa armigera) in cotton requires an integrated approach to minimize damage and protect crop yields. Here are various methods for controlling fruit borer in cotton:

Cultural control measures of Fruit Borer in Cotton:

• Plant cotton simultaneously with short-duration varieties to reduce pests.
• Don't grow cotton in the same area year-round or from old stubble.
• Use crops like greengram or soybean alongside cotton to minimize pests.
• Destroy crop leftovers to prevent pests from surviving between seasons.
• Proper use of nitrogenous fertiliser.

Biological control measures of Fruit Borer in Cotton:

• Release Trichogramma spp. (egg parasitoids) at a rate of 6.25 cc/ha every 15 days, starting 45 days after planting, for three times.
•  Release the egg-larval parasitoid Chelonus blackburnii and the predator Chrysoperla carnea at a rate of 100,000/ha in the 6th, 13th, and 14th weeks after planting.

Chemical control measures of Fruit Borer in Cotton:

FAQS Related to Fruit Borer In Cotton:

Q.What are damages caused by Fruit Borer in Cotton?

A:  The damage caused by Fruit Borer in cotton is by mining bolls and creating holes in leaves. All bolls can be damaged. The seeds stop growing, mature rapidly, and drop off. In legumes, flowers are attacked, and seed pods may be pierced.

Q. What is the best insecticide for Fruit borer in cotton?

A: The best insecticide for fruit borer in cotton is Katyayani Fluden and Katyayani Aakramak Plus.

Q. What is cotton borer?

A: The term "cotton borer" typically refers to the larvae of certain moths, particularly the cotton bollworm ,which are major pests in cotton cultivation. These larvae bore into cotton bolls, feeding on the seeds and damaging the cotton fibers, leading to reduced yield and quality.