Behavioral and electrophysiological responses of L. equestris to S. kuhlii body odor.

(A) Schematic of the Y-tube olfactometer used in two-choice assays. The cricket’s release position (junction) and airflow direction are indicated. (B) Choice percentages of crickets for the control versus test arm across three treatments: bat body odor, air without bat odor (control for odor bias), and (–)-limonene. (C) Representative gas chromatography–electroantennographic detection (GC–EAD) recordings. Upper panel: flame ionization detection (FID) chromatograms of bat body odor extract (brown) and an odor-free control (blue). Lower panel: corresponding EAD response (black) of a L. equestris antenna. Peaks 1–6 correspond to compounds identified by GC–MS (see panel D); asterisks mark compounds that elicited consistent antennal depolarizations (>0.1 mV). (D) Gas chromatography–mass spectrometry (GC–MS) total ion chromatograms of the same bat body odor sample (upper) and an odor-free control (lower). Identified compounds are labeled (peaks 1–6). Axes indicate retention time (x) and relative ion intensity (y).

Volatile organic compound (VOC) profiles of potential odor sources in S. kuhlii.

(A) Hierarchical clustering of VOC profiles from feces, hair, and snout secretions, based on compositional similarity (values normalized 0–1). All three odor sources were sampled from the same nine bats (27 samples total). (B) Principal component analysis (PCA) of VOC profiles from the same samples, based on compound presence/absence data, with the addition of a pooled body odor composite (combined from eight bats) for comparison. Ellipses represent 90% confidence intervals, and marginal density plots are shown for each source.

Electrophysiological and ecological responses of L. equestris to candidate bat body odor compounds.

(A) Electroantennographic (EAG) responses to four candidate compounds (n = 8 individuals). Significance versus the hexane control is indicated (**P < 0.001; repeated-measures ANOVA with Bonferroni-corrected paired t-tests). (B) Concentration-dependent EAG responses to (–)-limonene (n = 6 individuals). **P < 0.01, ***P < 0.001 versus control (same statistical test). (C) Mean call rate over time (calls per minute) in field plots treated with (–)-limonene (n = 8 datasets) or a hexane control (n = 7 datasets). Shaded areas represent 95% confidence intervals (1,200 recordings total).