Pests
Coffee berry borer (Hypothenemus hampei)
Coffee berry borer is the most serious pest of coffee world over. The female beetle bores into the berries through the navel region and makes tunnels in the hard bean and lays about 15 eggs. The larvae feed on the beans, making small tunnels.
A typical pinhole at the tip of the berries indicates the presence of the pest, and it damages young as well as ripe berries. In case of severe infestation, 30 to 80% berries may be affected resulting in heavy crop loss. The coffee berry borer can be controlled by the following methods.
Release of parasitoid C. stephanoderis and application of entamopathogen B. bassiana and installing Broca traps @ 60 nos. per ha for mass trapping are more effective. Pesticides should be used with extreme caution and only if no other option is available.
Timely and complete harvest, collection of gleanings, burying the infested berries and maintaining optimum shade and good drainage can control the pest.
Spraying quinalphos 0.05% with wetting agent 120-150 days after flowering (Aug - Sep or Arabica and Sep-Oct or Robusta) can control the pest. Spot spray of Chloropyriphos 20 EC at 600 ml in 200 litre of water along with 200 ml of any wetting agent may be used at the right time ie; 120-150 days after blossom.
White stem borer (Xylotrechus quadripes)
The adults have two flight periods as they emerge from the pupae during April-May and in September to December/January. As the beetles are active and females lay eggs in the crevices on the main stem of coffee, major efforts to control initial laying of eggs itself is aimed at by swabbing the main stem and the thick primaries with carbaryl 50 WP @ 4 kg in 200 litres of water once or twice (depending upon the severity of the incidence) in April-May or October to December. Apart from this, it is necessary to build up good shade and regularly trace, uproot stump and burn the infested plants. Storing of cut stems is not advisable, as it will advance the flight period.
Shot hole borer (Xylosandrus compactus)
This is a major pest in Robusta coffee affecting the secondary and tertiary branches causing considerable damage. Injury to the coffee plants is primarily by the extensive tunneling within the branches, which limits the flow of sap. The affected branches dry up. The presence of withering and dead branches with shot holes is the symptom of attack.
Control
- Prune the affected twigs 5-8 cm beyond the shot hole and burn. This operation should commence from September onwards, as soon as the first symptom of attack like dropping of leaves is noticed, and continued as a routine measure at regular intervals.
- The pest prefers to breed in the suckers during dry period. So remove and destroy all the unwanted / infested suckers during summer.
Mealy bugs (Planococcus sp.)
Mealy bugs damage coffee plants by sucking the sap from the tender branches, nodes, leaves, spikes, berries and roots leading to the debilitation of the plant. In case of root infestation, plants (especially young) become weak, leading to death.
Control
The mealy bug can be controlled by spraying any of the following three insecticides viz. quinalphos, fenthion or fenitrothion. In addition to the above method, the biological control agents like Cryptolaemus montrouzieri (ladybird beetle) and the parasitoid Leptomastix dactylopii have been found effective. Indirect control of the disease can be made by controlling the ants, which spread the infestation.
Green scale (Coccus viridis)
The green scale is a serious sucking pest of coffee particularly Arabica.
Control
The chemical control measures include spraying the affected patches with any one of the following insecticides viz. cythion 50 EC @ 200 ml, quinalphos 25 EC @ 120 ml or dimethoate 30 EC @ 170 ml in 100 litres of water.
Spray the affected patches with 2% kerosene emulsion (41 of kerosene in 200 l of water along with 200 ml of any wetting agent).
If root is affected, drench the root zone with Dimethoate at 0.09% ai (600 ml in 200 l of water)
(Source: Central Coffee Research Institute, Balehonnur)
