Symptoms

• The attack of nursery seedlings results in drying up of spindle leaf followed by gradual death of the seedlings. Holes can be seen at the collar region of damaged seedlings.
• In mature trees, continuous feeding on roots, results in yellowing of leaves, tapering of crown, premature nut fall, delayed flowering, retardation of growth and reduced yield. Peak season of attack is September-January.
• The grubs (Image1) may tunnel into the bole and collar region of the seedlings.
• The adult (Image2) emerges in June. Oviposition takes place in June-July in soil. Younger stages of the grubs feed on grass roots and organic matter while the later stages feed on coconut roots.

Control Measures

• Plough deeply and dig the soil to expose different stages of insects during pre & post monsoon periods.
• Collect and destroy adults during peak emergence in May-June.
• Set up light traps.
• Insecticides like Phorate (Thimet) 10G @ 100 g/palm or drench with Chlorpyriphos 20EC 2ml/L suspension. The treatment should be given twice. First during April- May after the receipt of premonsoon showers and second in September. Insecticide should be applied in the active root zone of the palm leaving a distance of 60 cm. There must be adequate moisture in the basin. .