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PESTS OF RICE (BORERS AND FOLIAGE FEEDERS) :: Minor Pests :: Rice Root Weevil - 1

14. Rice root weevil:  Echinocnemus oryzae (Curculionidae: Coleoptera)

Damage symptoms: Grubs feed on the roots of rice plants resulting in stunting and non formation of tillers.  Presence of dead plants in large patches is a typical symptom.

Bionomics: The adult weevil is shiny black with oblong body covered with greyish scales. The female lays eggs in soil near the roots of grasses.  The incubation period is 3-4 days.  The grub is creamy white, aquatic and feeds on root hairs.  The larval period lasts for 11 months.  The grub over-winters in soil at a depth of 25-30 cm, after September.  It pupates during May.  The pupal period is 10-12 days.