by:Bishnu Kumari Bhandari
Introduction
The coffee white stem borer, Xylotrechus quadripes (Coleoptera, Cerambicydae) is a major constraint for the successful cultivation of coffee in Nepal. This is the major pest for Arabica coffee. The adult is 1-2 cm length and black colour with white stripe on elytra. The size of the female is bigger than male. The Larva feeds the wood of the coffee plants to develop Adult; this effects the trees fructification and also lowers the quality of the coffee. If the infestation of the X.quadripes is high, the consequences are mortal for the coffee plant. Infested coffee plants are a high risk to all the others coffee plants in the orchard. >
Life Cycle
When the adult beetle emerges from the coffee plants, they immediately mate and after mating the female begins egg lay during October-November and April-June. The eggs hatch in about 14 days and the first instar larvae tunnel just under the bark for a period of 2 months. Later instars tunnel for up to a further 9 months and then bore a chamber close to the exterior of the stem before pupating. Total 6 stage (instar) larvae grow inside the coffee stem and it takes about 172 days to complete from first instar larvae to final instar larvae. It means larval stage can complete in 6 months when the last instar reaches the pupal chamber. Pupation lasts for 30-40 days.
The adult beetle remains in the pupal chamber for 3-7 days before cutting an exit hole, and the emerging adult immediately searches for a mate. The adult male live for 2-3 weeks whereas female survives for 9-30 days, during which time up to 100 eggs are laid in cracks and crevices of the bark on the main stem. The life cycle is completed in about 12 months.
Control
Maintenance of Proper Shade Condition
It is necessary to establish shade tree before going to coffee plantation. The shade tree for coffee plant should be multipurpose like soil fertility enhancing, fodder purpose and fast growing in nature.
Soil Moisture Management
The soil moisture management is very important for having healthy and vital coffeebusches. If the coffebushes get enough moisture, they will not be stressd. Vital coffeebushes are harder to be attacked by the WSB, then Coffeeplants wich are stressed. Therefor a well maintaind soil moisture plays a very central role in the preventive Managementmethods against the WSB.
Community Approach (Training Pruning Campaign)
The real purpose of removing infested plants from the field is to see that the borer will not develop into adults in the infested stem. For this to be achieved, the infested plants should be removed before the flight period. Hence, tracing can be done throughout the year but uprooting should be completed in the months of March for the summer flight period and in first week of September for the winter flight period. If this is practiced meticulously, the incidence can be kept very much in check. The uprooted infested stems should abe destroyed immediately by burning. If the wood has to be used as firewood, then it should be immersed under water for at least 10 days.
Application of Fermented Cattle Urine
Spraying of fermented cattle urine mixed with ketuki extract in whole plant is highly effective against this pest as it has repellent and antifeedant in nature. Therefore, it is necessary to spray the whole plant with cattle urine during the flight period of this pest.
Removal of loose scaly bark
The main purpose of this activity is to make unfavorable condition to lay eggs on main stem. This practice should be applied just before the flight period of this pest.
Pasting of red Soil mixed with fresh Cattle Dung
Scrubbing the main stem with the help of jute sacks and pasting with red soil mixed with fresh cattle dung especially for unshaded coffee.
Pheromone Trap installation in mass scale
This cross vane pheromone trap is specific to female adult borer but in highly infested area it can attract both male and female. It is highly effective against this pest only in high borer infested coffee area. If we install it in low infested coffee orchard, it can harbor the stem borer.
