Major Insect-pests Of Rice (oryza sativa)
1. Yellow stem borer: Tryporyza/ScirPophaga incertulus. • Family: Pyralidae (Lepidoptera)
• Monophagus/absolute pest of rice and pupates inside the plant.
• Full grown larvae measures about 20 mm. ” adults are dirty white or greenish yellow front wings.
• Caterpillar produce dead hearts which affected plants they attacked in early stages produce ears devoid of grains causes“white ear.
- Clipping and burning of tips of seedling of paddy plant before transplanting help to control Stem borer.
2. Rice hispa: Diclodispa armigera • F. Chrysomelidae, Coleoptera
• Serious pest of rice and damage is done by larvae as leaf minors, produce transparent blotches on the leaf surface.
• The adult also feed on green matter and produce parallel whitish streaks on leaves for control Clip off the leaf tips before transplanting seedlings to kill the eggs.
3. Rice gundhi bug: Leptocorisa acuta • F. Coreidae: Hemiptera
• Rice field severely attacked by this pest emit a repugnant smell which gives to this pest the name”gundhi bug”.The nymphs and adults suck juice from developing grains in the milky stage, causing incompletely filled panicles or panicles with empty grains.
• Black and brown spots are appearing around the holes made by the bugs on which a sooty mould may develop. •
4.Brown plant hopper: Nilaparvata lugens • F. Delphacidae: Hemiptera
• Serious pest of high yielding varieties of paddy. Both nymph & adult cause damage by sucking cell sap from leaves which turn yellow.
• Under the favorable condition of high humidity, high nitrogen application and no wind, the population increase and “hopper burn” is obtained in various localities.
• It transmitted the “grassy stunt” virus disease of rice.
5. Rice case worm: Nymphula depunctalis • F. Pyralidae: Lepidoptera
• The larvae are light green with a brownish orange head and the presence of filamentous gills which help larvae in aquatic conditions.Tubular case is constructed by the larvae and feed by scrapping the under surface of the leaf blade leaving the upper epidermis intact.
• A rope may be passed to over the young crop For dislodging the larval cases.Put filter barrier between irrigation channels of different field.
Other pests of rice:
a. Green leaf hopper: Nephotettex nigropictus/virescens. • Hemiptera: F. Cicadelidae
• This is responsible for vector of virus diseases, of which Tungro is most serious.
b. White backed plant hopper: Sogatella furcifera • F. Delphacidae: Hemiptera
• Cause rust red symptoms
c. Rice gall midge: Orseolia oryzae • F. Cecidomyiidae: Diptera
• Cause “silver shoot & onion leaves”symptoms.
d. Rice thrips: Stenochaelothrips biformis •F. Thripidae: Thysanoptera
• Important pest of rice nursery (JRF-09).
e.Rice grass hopper: Hieroglyph us banian • F. Acrididae: Orthoptera
• Damage by nibbling of rice ear head