In our country there are several pest attack rice plant at different different time of the rice plant life cycle.

They are categorised in 8 different groups. There are 
  •     Sucking pest
                   1. Gundhu bugs
                   2. Green leaf hopper
                   3. Zig Zag leaf hopper
                   4. Brown plant hopper
                   5. Thrips 
                   6. Mealy bugs
  
  •       Stem borer
                   1. Yellow stem borer
                   2. White stem borer
                   3. Pale headed  striped
                   4. Dark headed striped
                   5 .Ragi pink stem borer
  •       Defoliators
                  1. Swarming caterpillar
                  2. Skipper
                  3. Horned caterpillar
                  4. Grasshopper
  •        Leaf folder
                  Leaf folder
  •        Gall former
                Gall midge
  •        Case worm
                 Case worm
  •        Minor cum defoliators
                Hispa

  •        Non insect pest          
                1. Mites 
                2. Field rats 
                3. Crab

Some important pests are described  briefly in the below--------
   1. Gundhi bug 

      Scientific Name - Leptocorisa acuta 
     Order - Hemiptera 
     Family - alididae
  
Unpleasant odour indicative of their presence in the field, that's why this insect called gundhi bug.
    The pest appears on rice just before flowering stage and continuous until panicles ripen.

  •  Identification- 
         Nymph- 
                         Nymphs are pale   yellowish green possessing odoriferous glands on the fifth abdominal segment. Nymph passes through 5 instars in about 15-21 days.  The total life cycle takes about a month. After the harvest of rice, the bug over- winters in millets and wild grasses.
         Adult-
                     The adult is active, diurnal, elongated bug with long legs. It is olive brown and ventrally green measuring 15.5-17 mm long. 
         Eggs -
                Eggs are laid in single or double rows close to midrib on the upper surface of leaves @ 10-20 per cluster. Each female lays about 100 eggs. Dark reddish brown egg, is boat shaped . Egg hatch in about 7 days.
  
  • Nature of damage-
                            Both nymph and adult suck juice from grains in milky stage.
  • Damaging stage-
                           Nymph and adult.
  • Damaging symptoms-
         1. Grains are shrivelled and Chaffey.
         2. Brownish spot on seed.
           
       Management
•  Clean cultivation .
•  Collection of bugs by hand nets 
•  ETL : 1 or 2 bugs/hill 
•  Foliar sprays in the evening hours at milky stage starting from borders of the crop with dichlorovos 1 ml/l +  endosulfan 2 ml/l or  chlorpyriphos       2 ml/l or malathion 2 ml/l
 •  Dusting with endosulfan 4 D 10 kg/ac or carbaryl 10 D 10 kg /ac. 

         2. Yellow stem borer:

       Scientific name : scripophaga incertulas
      Order : Lepidoptera
       Family : pyralidae
  
  • Identification :
                           The female moth has bright yellowish brown forewings with a clear single black spot and the anal end having tuft of yellowish hair.  
The male is pale yellow and the spots on the forewings are not conspicuous. Male is smaller than female. 
 

  • Nature of damage :         
                           Larva bores into the stem and feed on inter content of the stem.
  • Damage symptoms:
                         1.   Dead heart   at vegetative stage.

                        2. White ear at reproductive stage.

  • Management:
       Monitoring :
                         Set up sex pheromone traps @ 2-3 traps / acre.
        Preventive measures :
           i.  Set-up  light  traps  to  attract  &  kill  the adult  female  moths .
           ii.  Clipping of  seedlings  before transplanting .
          iii.   Use resistance variety.      

         Curative measure
            I.  Collect  and  destroy of dead heart and white ears.
           II. Collect and destroy of egg masses.
          III. Spray fipronil 5 SC @ 2 ml/ lt  or spray Flubendiamide 48 SC @ 0.2 ml/ lt.

      3. Brown plant hopper:
       
        Scientific name: Nilaparvata lugens
       Order:                   Hemiptera
       Family:                  Delphacidae

  • Identification:
                  Adult males are brown dorsally and deep brown ventrally.
                   The females are 5 mm long and male 4.5 mm. Female exist in two form the fully winged macropterous ( strong fliers) and brachypterous ( weak fliers)


  • Nature of damage:
                                  Nymph and adult suck the sap at the base of the plant just above the water level.

  • Damage symptoms:
        I. Hopper burn in circular patches .
        II.Sooty mould
      III. Exuviae at the base of plant.
      IV.  Affected stem turn soft and unfit for  
         ideas straw.     

  • Management:
     Preventive measures:
         (I) Use resistance variety.
        (II) Do not use excess nitrogen fertilizer .
       ( III) AAlternate wetting and drying to avoid water stagnation.
       (IV) Conserve natural enemies like spiders ,mirid bug etc.
       (V) Avoid methyl parathion 50EC and pyrathroids to prevent resurgence.
   
    Curative measure:
         
          (I) Herding or droving of ducks through field.
          (II) spray Metarhizium anisopliae @ 2-5 gm/ lt.
         (III) spray  pymetrozine 50 wG @ 0.6gm / lt.

      4. Rice Gall midge:

      Scientific name: Orseolia oryzae 
      Order:.                Diptera
      Family:.               Cecidomyiidae

  • Identification:
                   Female has bright orange red abdomen, swifter with a reddish telescopic body. Male is darker and smaller. 
             
 
  • Nature of damage:
                      Maggot  feeds  on  ‘apical bud’ by  lacerating  the green tissues  &  inject  ‘a  chemical’ called  ‘Cecidgen’ into  the  ‘tissues’.
  • Damage symptoms:
                        Hollow whitish to pale green cylindrical tube in tillers known as gall / silver shoot/onion shoot bearing at its tip a green, reduced leaf blade complete with ligules and auricles. Gall is a modified leaf sheath.  

Vigorous subsidiary tillering if infested in early growth period .
  • Management:
         Preventive measures 
 
            (I)  Avoid late  planting 
           (II) Use resistant  varieties   

           Curative measures 

                        spray any  one chemical Insecticide:
          Buprofezin 25 EC @ 1 ml / lt
          Thiamethoxam  25 WG @  0.2 gm / lt

     5. Rice leaf folder :
      Scientific name: Cnaphalocrocis medinalis
      Order:.                 Lepidoptera
      Family:.                Pyralidae

  • Identification:
                               This is widely distributed in India occurring in all rice growing tracts. Moth is small with a wing span of 15 mm, brownish orange coloured with light brown wings having two distinct dark wavy lines on forewings and one line on hind wings. Both wings have  dark brown band on their outer margin. Adult longevity is 3-4 days. 


  • Nature of damage:
                            Larva  ‘folds  margins  of  leaf  blade  together  with  its  saliva’ &  ‘feeds  within’  by ‘scrapping  green tissu.
  • Damage symptoms: 
                   Whitish membranous folded             leaves with typical   white streaks .
                    Faecal pellets when leaf opened .
                    Reduced vigour of the plant  . 
  • Management:    
              Preventive measures: 
             (I)  Avoid   excess  use of  nitrogen fertilizers .
           (II)  Apply  ‘K’ at  higher  dose 

            Curative  measures :

          (I ) Inundativer of  Trichogramma chilonis @  50,000/ha/week  for  5-6  times 

              ( II) spray Metarhizium rileyi @ 2-5g/l  (2X108 CFU/g) .

          (III)Spray  B.t.  products @  2g/ml .

          (IV)  Spray azadarachtin 1EC @  2ml/l .