Coffee Farming/White Stem Borer
The insect coffee white stem borer (WSB; botanical name Xylotrechus quadripes) is a pest for coffee plants. In many Arabica coffee plantations, WSB is the pest doing the most damage. Without countermeasures, WSB can reduce the harvest by as much as 60% and leads to the death of the infected coffee plants.
Symptoms on coffee
For completeness, this section also includes non-organic countermeasures. Of course, pesticides are not to be used in organic agriculture.
- Choose cool locations / altitudes. Occurence of WSB seems limited by temperature, which also means, by altitude because temperature drops with altitude. One reference to this comes from coffee growers in Nepal, reporting that WSB occurs up to 1300 m altitude in the 2015/16 season but not above and that in previous years where temperatures were lower, its altitude limitation was lower as well. It should be possible to recommend temperature profiles and safety margins that identify a "WSB safe" coffee growing location.
- K. Bhaskara Reddy: Management of Coffee White Stem Borer. A presentation slide deck that serves as a good introduction to mechanical and cultural management practices for WSB.
While WSB does a lot of damage, it does not mean that it is invincible – we just have not found an effective and cheap, organic way to control it yet. That is in part because of the structural inequalities of international coffee trade: coffee-producing countries are mostly poor and / or small countries, not able to organize and fund a larger amount of research into organic coffee pest control. Coffee importing countries, on the other hand, are only interested in the final product; they can afford to pay for coffee even when half the harvest were regularly lost to WSB.
- K. Petrie: The White Stem Borer: A Threat to the Nepalese Coffee Industry?. 2016-04-06, section "A Changing Climate Leads to Coffee Pests" (accessed 2016-08-19)
- K. Bhaskara Reddy: Management of Coffee White Stem Borer. (accessed 2016-08-19)
- Fernando E. Vega, Francisco Posada: Coffee Insects: Ecology and Control. p. 3, section "Conclusions" (accessed 2016-08-19). Appears in: Encyclopedia of Pest Management, Taylor & Francis, 2006.