Fig. 2. Total excitatory responses of the medial (A,C) and lateral (B,D) sensilla to stimulation with the control solution (i.e. 100 mmol l^–1 KCl) or one of the carbohydrates: Polycose (100 mmol l^–1), maltose (200 mmol l^–1), trehalose (200 mmol l^–1), fructose (200 mmol l^–1), glucose (200 mmol l^–1), sucrose (200 mmol l^–1) and myo-inositol (1 mmol l^–1). We presented each carbohydrate in the control solution. In panels A and B, we show the total number of spikes elicited in the medial and lateral styloconic sensilla, across the initial 1 s of stimulation. Within each panel, we compare means with a post-hoc test (Tukey's HSD test); different letters (a, b, c or a combination of each) above the bars indicate means that differ significantly from one another (P0.05). In panels C and D, we show concentration–response functions for a range of inositol, glucose and sucrose concentrations in both the medial and lateral styloconic sensilla. Each bar or symbol indicates mean ± s.e.m.; N=7–18 sensilla per tastant (each from a different caterpillar).