Whorl Maggots
Whorl Maggot (Hydrellia philippina Ferino) larva damages rice plant during its seedling to tillering stage. The larva uses its hardened mouth hooks to rasp the tissues of unopened leaves or the growing points of the developing leaves. The damage becomes visible when the leaves grow old. Mature larva prefers to feed on the developing leaves of the new developing tillers at the base of the rice plant.
Source: http://www.knowledgebank.irri.org
What are the symptoms
Check for presence of insect:
√ elongate, white eggs on leaves
√ transparent to light cream legless young larvae rasping the tissues of unopened leaves
√ yellow mature larva feeding on developing leaves of the new developing tillers at the base of the rice plant
Monitor also the damage caused by whorl maggots such as:
√ white or transparent patches, pinholes, clear or yellow spots on inner margins of emerging leaves
√ damaged leaves easily break from the wind
√ distorted leaves, stunted growth, few tillers
Source: http://www.knowledgebank.irri.org
Impact to the crop
Whorl Maggot starts infesting rice plant as early as seedling stage during transplanting. It may also delay crop maturation up to 2 weeks.
How to control
√ Drain the field with 3 to 4 days intervals during the first 30 days of the rice plant
√ Use of biological control agents like wasps, grasshoppers and spiders attack whorl maggot
√ Chemical Control - use of insecticide registered for control of whorl maggots
Source: http://www.knowledgebank.irri.org
