Coffee Bean Weevil (Araecerus fasciculatus)

A Silent Threat to Coffee and Stored Agricultural Products

The Coffee Bean Weevil (Araecerus fasciculatus) is a small beetle that causes significant damage to both fresh and stored agricultural products—particularly coffee beans, dried cassava, and various dried goods such as spices, herbs, and flours. Though small, it is a persistent pest that affects product quality and market value, especially in high-value crops like coffee.

This insect is widespread in tropical and subtropical regions, particularly where high humidity and poor post-harvest management exist.

Basic Information

• Common Name: Coffee Bean Weevil
• Scientific Name:Araecerus fasciculatus (De Geer)
• Family: Anthribidae
• Order: Coleoptera

Morphological Features

• Body Size: 3.0–5.0 mm
• Color: Grayish-brown with white and dark-brown hair patterns
• Antennae: Capitate (clubbed), with enlarged tips
• Forewings: Hardened elytra
• Hindwings: Transparent membranes
• Legs: Walking legs with distinct white banding on each tarsus
• Mouthparts: Chewing type
• Eggs: Slender, white
• Larvae: Cylindrical, legless, yellow-brown

Biology & Behavior

• Naturally found on tree bark, leaves, decaying plant matter, and organic soil
• Prefers laying eggs in fermented, acidic, or dried fruit-based substrates
• Not a disease vector but a major quality-damaging pest for stored goods

Life Cycle (Complete Metamorphosis)

• ~50 eggs/female
• Hatch in 3–5 days (depending on temperature and humidity)

• Develops inside coffee beans or dried plant materials
• Thrives in environments with >60% RH

• Slower development under low humidity
• Lasts 29–57 days

• Lifespan ~17 weeks
• Total life cycle: 46–66 days

Host Plants & Damage Symptoms

Affected Crops:

• Coffee beans
• Dried cassava, yam, taro
• Cocoa, ginger, ginseng, garlic
• Dried spices, wheat flour, cassava flour, millet, etc.

Damage:

• Larvae burrow and feed inside dried seeds or tubers
• Reduces internal quality, causes hollowness and weight loss
• Although not always visible, damage significantly reduces grade and market price

Geographic Distribution

• Native to India
• Now found throughout humid tropical and subtropical regions
• Common in poorly managed post-harvest storage zones, including Southeast Asia

Prevention & Control Strategies

✅ Cultural Practices:

• Harvest coffee at optimal timing
• Remove overripe or fallen coffee fruits from trees and ground
• Prune trees to allow airflow
• Avoid drying coffee cherries on bare soil or near production fields

✅ Biological Control:

• Apply Beauveria bassiana (entomopathogenic fungus) to soil or plantation floors
• Use chili powder or botanical repellents around tree bases
• Deploy bait traps to reduce adult populations

 Note: This weevil often overwinters in soil and re-emerges with the next crop cycle.

✅ Conclusion

While Coffee Bean Weevils (Araecerus fasciculatus) are not known vectors of disease, they pose a serious threat to the quality of high-value dried agricultural products like coffee, cocoa, and medicinal herbs. Effective control requires an integrated approach—combining physical, cultural, and biological methods—to ensure product quality and reduce post-harvest losses sustainab