Olfactory-mediated chemotaxis toward a key host plant leaf volatile in the fall webworm

Area of Science:

• Entomology
• Chemical Ecology
• Molecular Biology

Background:

• Olfaction is vital for insect survival, guiding behaviors like host plant selection.
• The invasive fall webworm (Hyphantria cunea) relies heavily on olfactory cues for host location.
• Specific volatile compounds triggering larval responses in H. cunea are not well understood.

Purpose of the Study:

• To identify key olfactory attractants for fall webworm larvae.
• To characterize the molecular mechanisms underlying host plant recognition in H. cunea.
• To explore potential targets for invasive pest management.

Main Methods:

• Behavioral assays and electrophysiology to test volatile responses.
• Quantitative real-time PCR (qPCR) to assess gene expression.
• Calcium imaging and single sensillum recordings to study receptor function.
• RNA interference (RNAi) to knockdown receptor expression.

Main Results:

• Cis-3-hexenyl acetate (Z3HAc) was identified as a potent chemoattractant for H. cunea larvae.
• The antennal receptor HcOr3 showed high expression and selective Z3HAc response.
• Knockdown of HcOr3 significantly reduced larval attraction and antennal sensitivity to Z3HAc.

Conclusions:

• Z3HAc is a critical host plant volatile for H. cunea larvae.
• The HcOr3 receptor is essential for detecting Z3HAc and likely mediates host recognition.
• This research provides insights into insect olfaction and identifies HcOr3 as a potential target for fall webworm control.