Survey for incidence of coffee white stem borer, Xylotrechus quadripes (Chevrolet) on robusta coffee (Coffea canephora Pierre ex A. Froehner) plantations at Kodagu region of Karnataka state, India

Coffee is an important commercial crop attacked by various insect pests. Among them, coffee white stem borer (CWSB), Xylotrechus quadripes (Coleoptera: Cerambycidae), is the most serious and economically important pest of arabica coffee. The incidence of CWSB has been noticed in arabica coffee, whereas the other commercial variety, viz., robusta, has been tolerant against this pest so far. Of late, the incidence of CWSB is reported regularly in robusta plantations in the Kodagu region of Karnataka State, India. To understand the extent of CWSB incidence in robusta coffee, a systematic survey was conducted in 40 estates of Polibetta and Siddapura liaison Zones during the year 2019. CWSB infestation and the details on the percentage of CWSB, cultivar types, and age of the plants were recorded. The results of the survey revealed that the incidence was more in aged plants of Old Peridenia and S.274 (>50 years) compared to young plants and C × R hybrid (Coffea congensis × Coffea canephora). Data on the percentage infestation was found more in Old Peridenia (16.81%), followed by S.274 (4.8%) and C × R (0.88%). The infested plants of Old Peridenia and S.274 showed typical symptoms as in the case of arabica plants like ridge formation, drooping and yellowing of leaves, wilting, defoliation, exit holes and death of branches and whole plants. Hence, Indian coffee farmers are shifting slowly from arabica to robusta coffee because of CWSB infestation. This survey emphasized that a complete shift from arabica to robusta cultivation may face a similar infestation problem unless management practices are followed promptly.