Plantation Crops

White stem borer (Xylosandrus quadripes/Xylotrechus quadripes )

• Most serious pest of arabica coffee in India
• Robusta coffee is free from this pest

Method of damage
Grubs feed on the corky portion under the bark for about two months.

Symptoms of attack
Spitting of bark === Tunnelling even hard wood in all the directions == Externally visible ridges are seen around the stem === Yellowing and wilting of leaves ===Less productivity with more of float beans ( floats)

Management of white grub in coffee
Shade management: Maintenance of optimum shade
Removal of affected parts /trees prior to flight period: Prior to flight period ( i.e., the period of emergence of adult beetles and in flight period beetles will escape by flying) Once in April – May and other in October – December.
Minimising the scope for egg laying i.e. , Scrubbling : Eggs are laid on the loose scaly bark of the main stem and thick primaries. Hence, removing loose scaly bark of main stem and primaries using coconut husk is suggested. Scrubbling ( rubbing) during flight period not only prevents egg laying but also kills eggs and grubs.
Swabbing /Spraying: During April – May, and October – November
Insecticide recommended: Lindane 20 EC @ 6.50 ml per litre of water. ( i.e., 1300 ml per 200 litres barrel)
Spraying of main stem and thick primaries with neem kernel extract may be effective. However, as the persistence of neem derivatieves is only for a short period, repeated applications may become necessary.