Gomphus kinzelbachi

Males of G. kinzelbachi compared to G. davidi

The distinctive characters of the primary and secondary genitalia of a teneral G. kinzelbachi male given in the species description could be confirmed on 14 mature male specimens of G. kinzelbachi. Overall we found no clear difference in colour pattern between the two species (Fig. 2 A–F, 3 A–D). However, the tips of the inferior anal appendages are not visible in G. kinzelbachi if viewed directly from above in contrast with G. davidi (Fig. 3 E, G). The superior appendages from above are stouter and tapering just before the tip in G. kinzelbachi, while they are slender and tapering continuously in G. davidi (Fig. 3 E, G). The superior appendages from the side have a small subapical denticle overtopped by a bulge behind it in G. kinzelbachi, whereas this denticle is more pronounced and free-standing in G. davidi (Fig. 3 E, G). The apical part of the posterior hamule shows a more acute and pronounced tip in G. kinzelbachi than that of G. davidi (Fig. 3 F, H). The anterior hamule is longer in G. kinzelbachi compared to G. davidi. The anterior hamule is only one third of the posterior hamule in G. davidi and nearly one half of the posterior hamule in G. kinzelbachi (Fig. 3 F, H).

G. kinzelbachi males were significantly smaller than males of G. davidi (Fig. 4). The mean total length is 45 mm (43–47 mm) in G. kinzelbachi (n = 14), and 52 mm (50–54 mm) in G. davidi (n=14), unpaired t test: p <0.0001; t-value (t) = 15.27; degrees of freedom (df) = 26. This difference was also reflected by abdominal length 33 mm (32–34 mm) versus 36 mm (35–37 mm) and hindwing length 30 mm (27–33 mm) versus 33 mm (32–34 mm), unpaired t test: p <0.0001 (t = 10.11; df = 26), and p <0.0001 (t = 5.736; df = 26), respectively.