Table 3.

Morphometry of the feeding apparatus of the long-tongued species (Eurybia elvina, Eurybia lycisca, Eurybia unxia) and the short-tongued species (Euselasia aurantia, Mesosemia asa, Sarota gyas)

	Long-tongued (N = 6)			Short-tongued (N = 6)			Mann–Whitney U-test
	Median	Minimum	Maximum	Median	Minimum	Maximum	Z	P
Body size
Body length (mm)	18.9	16.8	20.7	11.3	6.2	11.9
Head capsule volume (mm3)	1.6	1.2	2.0	0.8	0.2	0.9
Suction pump
Dilators (mm3)	0.056	0.045	0.077	0.020	0.003	0.026
Dilators (% of head capsule)	3.6	3.4	3.8	2.2	1.3	3.6	−2.242	0.026
Compressors (mm3)	0.025	0.018	0.030	0.011	0.003	0.021
Compressors (% of head capsule)	1.4	1.2	2.0	1.6	1.0	2.6	−0.641	0.589
Haemolymph pump
External stipes muscles (mm3)	0.115	0.091	0.151	0.007	0.003	0.014
External stipes muscles (% of head capsule)	7.4	6.4	7.6	1.4	0.7	1.7	−2.882	0.002
Internal stipes muscles (mm3)	0.015	0.010	0.020	0.001	0.001	0.002
Internal stipes muscles (% of head capsule)	0.9	0.7	1.0	0.2	0.1	0.3	−2.882	0.002
Galea
Galeal length (mm)	35.1	29.1	40.2	3.4	2.6	5.7
Tip length (mm)	1.4	1.0	1.7	1.5	0.6	2.1
Tip length (% of galeal length)	3.8	3.0	5.5	33.0	21.3	47.3	−2.887	0.002
Galea (mm3)	0.189	0.136	0.233	0.022	0.020	0.043
Cuticula (mm3)	0.110	0.072	0.133	0.007	0.006	0.012
Cuticula (% of galeal volume)	57.3	52.9	61.7	31.3	24.7	36.4	−2.882	0.002
Food canal (mm3)	0.050	0.033	0.060	0.004	0.001	0.005
Food canal (% of galeal volume)	24.7	24.2	30.3	14.6	1.5	23.4	−2.882	0.002
Internal galeal muscles (mm3)	0.010	0.007	0.014	0.002	0.001	0.002
Internal galeal muscles (% of galeal volume)	5.7	3.9	6.3	6.2	4.3	10.9	−0.801	0.485
Sensilla styloconica number	30.5	20.0	38.0	64.5	23.0	83.0
Sensilla styloconica (per mm tip length)	22.2	11.8	38.0	40.7	38.3	48.0	−2.882	0.002
Sensilla trichodea number	294.0	192.0	373.0	71.0	55.0	91.0
Sensilla trichodea (per mm galeal length)	8.8	5.3	9.8	21.0	11.6	27.1	−2.882	0.004

Volumetric parameters were compared using the Mann–Whitney U-test (N = 6 individuals per group).