Influence of Endogenous Bacteria on Behavioral Responses in Leptocybe invasa: An Analysis of mVOCs

TL;DR

This study explores how bacteria inside Leptocybe invasa influence the insect's behavior through volatile organic compounds.

Contribution

The study identifies specific bacterial mVOCs that attract or repel L. invasa, offering new insights for pest control.

Findings

Staphylococcus sp. bacteria attract L. invasa the most.

Microbacterium sp. and E. cloacae cause the strongest avoidance behavior.

Aldehyde and alkane compounds like 2,3,6-trichlorobenzaldehyde and eicosane mediate these effects.

Abstract

This study investigates the impact of the mVOCs emanating from nine cultivable endogenous bacteria within Leptocybe invasa on the host’s behavioral selection.

Microorganisms within insects play a vital role in maintaining the basal physiological functions of the insects, with olfactory signals as critical components of insect survival strategies. Leptocybe invasa (L. invasa), an invasive alien pest inflicting significant damage to eucalyptus trees, harbors a rich and varied bacterial community within its body. However, the impact of its endogenous bacteria and their microbial Volatile Organic Compounds (mVOCs) on the behavioral preferences of L. invasa remains unexplored to date. This study focused on nine cultivable and dominant endogenous bacterial strains within L. invasa. Using a Y-tube olfactometer, we investigated the behavioral responses of female L. invasa to the mVOCs emitted by these bacteria. Concurrently, gas chromatography–mass spectrometry (GC–MS) was employed to quantify the mVOCs produced by these endogenous bacteria. Our findings revealed that Staphylococcus sp. exhibited the highest attractiveness of L. invasa, whereas Microbacterium sp. and E. cloacae exerted the most significant avoidance effects. The analysis of the mVOCs further highlighted the significance of aldehyde compounds, notably 2,3,6-trichlorobenzaldehyde, and alkane compounds, such as eicosane, in mediating the repellency and attraction effects. These results contribute to a deeper understanding of the invasion mechanism of L. invasa and provide a scientific basis for developing novel biopesticides or elicitors.

Figures