Preference for Coffee varieties and Volatile compounds by Coffee White Stem Borer, Xylotrechus quadripes

Author: Prashant Mangalgikar, Karumuru Raja Madhura Bhanu, Vasuki Belavadi, Chandrashekharaiah Muniyappa and Byrappa Ammagarahalli

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Abstract

The study revealed a significant difference in host preference between male and female Coffee white stem borer (CWSB) beetles in response to arabica and robusta coffee varieties. When arabica was positioned in the W-N and E-S directions and robusta in the N-E and S-W directions, both male and female beetles distinctly favored arabica coffee, as indicated by χ2 values of 21.49 and 22.01, respectively. Altering the spatial orientation of host plants, with arabica in the W-N and N-E direction and robusta in the S-W and E-S direction, led to a significant difference in female preference (χ2=11.58), while no significant difference was observed in male preference (χ2=2.56). In Y-tube olfactometer experiments, female CWSB beetles displayed a significantly higher response to Cauvery bark volatile (66.67) compared to the control (33.33) (χ2=11.11). Additionally, a higher response to (E)-2-hexenal (79.33) compared to (Z)-3-hexenol (17.33) was noted (χ2=39.76). These findings shed light on the preferences and responses of female CWSB beetles to various volatile compounds, offering insights for pest management strategies. Overall, the results emphasize the stronger inclination of CWSB towards arabica coffee compared to robusta. This preference may contribute to the higher incidence of CWSB infestation in arabica coffee plantations.

Keywords

Behavior, Y-tube olfactometer, Arabica coffee, Xylotrechus

Conclusion

Female CWSB beetles exhibited a substantial preference for arabica coffee, while males displayed a non-significant preference. In the Y-tube bioassay, a notable distinction in preference was evident in female CWSB beetles when comparing arabica and robusta coffee bark volatiles, arabica bark volatiles, and the control. However, no significant difference was observed between robusta bark volatiles and the control. These findings align with the established understanding of CWSB behavior, highlighting the nuanced host preferences exhibited by females, particularly in response to coffee bark volatiles. The differential responses between male and female CWSB beetles emphasize the importance of considering gender-specific behaviors in the context of pest management strategies, and they provide valuable insights into the chemical ecology of these insects.

References

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How to cite this article

Prashant Mangalgikar, Karumuru Raja Madhura Bhanu, Vasuki Belavadi, Chandrashekharaiah Muniyappa and Byrappa Ammagarahalli (2023). Preference for Coffee varieties and Volatile compounds by Coffee White Stem Borer, Xylotrechus quadripes. Biological Forum – An International Journal, 15(10): 1186-1190.