Plantation Crops

PESTS OF COCONUT

1. Rhinocerus beetle: Oryctes rhinoceros

 
• It is a most serious pest of coconut,

  Stage of damage of insect:
  
• Adult beetles which are usually active during night (Nocturnal). The adult beetles have dark brown to black colour and it is characterized by the presence of a horn on the haed.

Nature of damage:
• Boring the soft tissues of the growing bud or cabbage (i.e., un opened fronds and spathes) by cutting and chewing the tender unopened leaves and spathe. It also destroy the inflorescence while chewing leading to direct (Prevents the nut production) and indirect losses.
• Triangular / Geometric cuts: The attacked fronds when fully opened shows characteristic triangular cuts and there will be presence of chewed up material around the hole.
• Death of palm: The repeated infestation by the beetles lead to the death of palm

Management / Control
• Sanitation in the plantation: Sanitation in the plantation has to be maintained by proper disposal of decaying organic debris, Eg: Cattle dung, Compost etc.
• Manure pits and other possible breeding sites are to be treated with carbaryl (10%) @ 350 g / 3 m3 pit (1 m depth, 1 m width and 3m length) . OR Manure pits and other breeding sites are to be treated with carbaryl 50 WP at 0.01 per cent concentration. Spraying is to be done thrice i.e., During April, September and December.
• Mechanical Removal : Hook out the beetle from the attacked palms using beetle hook.
• As a prophylactic measure, fill up the top most three leaf axils with Sevidol 8G(25g) + fine sand (200g) thrice in April, September and December.
• Remove the beetles from the infected fronds with the help of beetle hook and fill up the innermost 2-3 leaf axils with Malathion + Sand or Qinolphos + sand In equal proportion (100g each ) .
• Leaf axil filling is to be done thrice a year i.e during April, September, and December.
• Filling leaf axils with 12 g napthalene balls (approximately three balls ) covered with fine sand at 45 days interval is also effective (Ref: Coconut cultivation technology by Coconut Development Board)