Cylindrostethus

Floriano, Carla Fernanda Burguez & Cavichioli, Rodney Ramiro, 2013, A new species of Cylindrostethus Mayr (Hemiptera, Gerromorpha, Gerridae) for the Neotropical Region, with an identification key for the species of Group 1 sensu Drake 1952, Zootaxa 3702 (2), pp. 187-192 : 191

Key to males of the species Group 1 (sensu Drake 1952) of Cylindrostethus from Neotropical Region

1. Basolateral processes of proctiger very small, not visible in dorsal view ( Fig. 10 ); small spines present all over the posterior region of sternites V and VI ( Fig. 12 )...................................................... C. bilobatus Kuitert

1’. Basolateral processes of proctiger long or very long, visible in dorsal view ( Figs. 11 and 14 ); very small spines on central region of sternites IV to VI ( Fig. 13 )...................................................................... 2

2. Sternites IV and V without depressions; distance between apices of basolateral processes equal or slightly shorter than proctiger (Fig. 03); apices of the basolateral processes of the proctiger, in dorsal view, not hidden by spines of connectives (Figs. 0 1 and 12).............................................................................................. 3

2’. Sternites IV and V with light depressions; distance between apices of basolateral processes greater than 1.2 times median length of proctiger ( Figs. 15 and 16 ); apices of basolateral processes of proctiger, in dorsal view, hidden by spines of connectives (fig. 14)........................................................................................ 4

3. Basolateral processes of proctiger with rounded apices (fig. 11).................................... C. bassleri Drake

3’. Basolateral processes of the proctiger with sharp apices (fig. 0 1, 0 2 and 03)....... C. meloi sp. nov. Floriano and Cavichioli

4. General coloration brown or tan; width of tergite VII not greater than 1.2 times that of tergite II; sternites IV, V and VII with lateral depressions; basolateral processes strongly convergent; anterior width about 3/10 posterior width ( Fig. 15 )............................................................................................. C. linearis (Erichson)

4’. General coloration blackish; width of tergite VII greater than 1.25 times tergite II; sternites IV, V and VII with central depressions; basolateral processes not strongly convergent; anterior width about 5/10 the posterior width ( Fig. 16 )....................................................................................... C. erythropus (Herrich–Schaeffer)

Figures

FIGURES 10 – 16. (10): C. bilobatus, male genitalia, dorsal view; (11): C. bassleri, male genitalia, dorsal view; (12): C. bilobatus, male genitalia, ventral view; abdomen, ventral view; (13): C. erythropus, male abdomen, dorsal view; (14) C. linearis, male genitalia, dorsal view; (15): C. linearis, proctiger, dorsal view (16): C. erythropus, proctiger, dorsal view.