Insect Pests of Vegetable, Ornamental and Spice Crops (2+1)

Rhizome weevil

6. Rhizome weevil, Prodioctes haematicus (Curculionidae: Coleoptera)

Distribution: Different states of south India.

Damage

• Damage is caused by grubs
• Tunnel and feed inside the rhizomes
• Death of entire plumps of the cardamom plants.

Identification

• The adult is a brown weevil measuring 12 mm in length.

Life cycle

• Grubs emerge from the eggs in 8-10 days
• Larvae become full fed in three weeks
• Pupate for 3 weeks.
• Adult weevils live for 7-8 months.
• There in only one generation in a year.

Salient features

• The weevils emerge during April, soon after an early shower of the monsoons
• Bore into the rhizomes by making tunnels
• Larvae feed inside the rhizomes and become full fed in three weeks
• They pupate within the feeding tunnels

Management

• Destroy effected plants/seedlings
• If grub population is more in the soil, drench with 1.25 L of malathion 50 EC in 625 L of water per hectare

Insect pests of large cardamom

• Hairy caterpillars, Clelea plumbiola
• Stem borer, Glyphipterix sp.
• Beetles, Chrysomela sp
• Georgria quadrimaculata
• White grubs

Minor pests of cardamom:

• Wingless grasshoppers, Orthacris sp. (Acrididae: Orthoptera)
• Leafhopper, Tettigoniella ferruginea (Cicadellidae: Hemiptera)
• Spittle bug, Aphrophora nuwarans (Aphrophoridae: Hemiptera)
• Banana lace wing bug, Stephanitis typica (Tingidae: Hemiptera)
• Thrips, Leewania maculans (Thripidae: Thysanoptera)
• The bag worm, Acanthopsyche bipars (Psychidae: Lepidoptera)
• Root borer, Hilarographa caminodes (Plutellidae: Lepidoptera).
• Cutworm, Nocloa plagiata (Noctuidae: Lepidoptera)
• Root gall midge, Hallomyia cardamomi (Cecidomyiidae : Diptera)