Rice In Sri Lanka - Pests of Rice
Rice Gall Midge
Coleoptern predatory beetle have been identified.The larvae move down between the leaf sheaths until they reach the apical bud or one of the lateral buds. They lacerate the tissues of the bud and feed until pupation.The feeding cause formation of a gall called a “Silver” or “Onion” shoot.Galls terminate the tiller development and hence affect rice yield.
- Damage is high in wet humid weather.
- Infestation is high,in dry and intermediate zones in maha in the wet zone during yala.
- Severity of damage is related to the crop growth stage of attack.
varieties such as Ptb 18/ Ptb 21 and Eswarakora has been used to develop a number of improved varieties with resistance to gall midge.
The gall midge biotype detected after 1986 is termed as biotype II.
Varieties resistant to biotype I are:
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Varieties resistant to biotype I and biotype II are:
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Effective control methods
- Granular insecticides are recommended for gall midge control. Since farmers use granules after observing damage symptoms it is difficult to obtain a good control with granules.
- Cultivation of resistant varieties in endemic areas is the most economical method.
- Controlling Weeds