Cosmopolites sordidus

(Germar, 1823)

banana root borer, banana borer, banana weevil

is a serious pest of banana with distribution throughout banana-growing regions worldwide. are approximately 11 mm long with greyish-black to dark brown coloration. The is considered the most damaging insect pest of bananas, with larvae burrowing into stems and corms causing plant weakening, lodging, and yield reduction. The complete takes 30–40 days.

Pronunciation

How to pronounce Cosmopolites sordidus: //kɒzməˈpɒlaɪtiːz ˈsɔːrdɪdəs//

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Identification

Distinguished from similar billbugs (Sphenophorus) by the absence of thoracic depressions. The presence of hook-like claws on the tibiae is a distinctive feature. are and poor fliers.

Habitat

Found in banana plantations and areas with Musa . Occupies moist soil and banana pseudostems where relative humidity ranges 90–100%. Cryptic characterized by high humidity conditions. In the United States, restricted to Monroe and Miami-Dade Counties in Florida.

Distribution

distribution throughout all banana-growing regions worldwide. Probably originated in southeastern Asia and Indonesia. Present in southern Asia, Africa, Macaronesia, Australia, South and Central America, West Indies, Mexico, and limited areas of Florida (USA). Easily transported in larval stage within root or corm sections.

Diet

Feeds primarily on Musa (bananas), with preference for plantains and East African Highland bananas (matoke) over dessert and brewing bananas. Attracted to plants by volatile chemicals, especially from damaged corms. Has been reported feeding on Manila hemp, sugarcane, and yams, but likely only when banana plants are unavailable.

Host Associations

  • Musa - primary All banana ; preference for plantains and East African Highland bananas
  • Manila hemp - secondary Reported feeding when banana unavailable
  • sugarcane - secondary Reported feeding when banana unavailable
  • yam - secondary Reported feeding when banana unavailable

Life Cycle

Complete takes 30–40 days. female deposits singly between leaf and stem, or at base of stem near corm. Eggs hatch in approximately six days. Larval stage lasts 15–20 days; larvae burrow into stem or root, weakening the plant. occurs within plant tissues.

Behavior

are , poor fliers, and have low with limited natural . Exhibits strong hygrokinetic response, moving toward higher humidity. Optimal activity occurs at 90–100% relative humidity; locomotory activity decreases significantly below 80% RH. potential is greater than previously reported, with individuals capable of moving at least 70 meters.

Ecological Role

Major herbivore pest in banana agroecosystems. Larval tunneling activities weaken plants and increase susceptibility to lodging. Serves as prey for ; the Plaesius javanus preys on , all larval stages, pupae, and in southeastern Asia and has been introduced elsewhere for .

Human Relevance

Considered the most serious insect pest of bananas globally. Causes economic damage through yield reduction, plant lodging, and failure of newly planted stands. Management strategies include use of clean planting material, removal and destruction of , and trapping. using Plaesius javanus has been attempted.

Similar Taxa

More Details

Humidity requirements

Strong behavioral to high-humidity environments; humidity preference of approximately 96% RH demonstrated in gradient experiments

Pheromone attraction

The synthetic sordidin is used in trapping; equally attractive to pseudostem at 0–10 m, but more attractive at 10–100 m distances

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Sources and further reading