Pleciogonus pacholatkoi, Zettel & Chen, Zettel & Chen

Raruanysong, Sajeemat, Vitheepradit, Akekawat & Sites, Robert W., 2014, Key to the species of Ptilomerinae (Hemiptera: Heteroptera: Gerridae) of Thailand and review of the fauna of the Tennaserim Mountain Range, Zootaxa 3852 (1), pp. 101-117 : 113-114

Pleciobates pacholatkoi Zettel & Chen

Figs. 6, 7 , 40 , 43, 44

Pleciobates pacholatkoi Zettel & Chen 1996: Entomol. Abhand. Mus. Tierk. Dresden 164–166.

Diagnosis. Males of this species can be distinguished by the paramere noticeably wider near the middle ( Fig. 40 ), whereas in P. tuberculatus the paramere is of even thickness throughout, except at the base ( Fig. 41 ). Females can be distinguished by abdominal sternite VII with a straight to slightly concave posterior margin and the connexival spines are curved outward and slightly decurved ( Figs. 43, 44 ), whereas in P. tuberculatus sternite VII is distinctly concave and the connexival spines are convergent and slightly depressed or directed straight caudad ( Figs. 45, 46 ).

Discussion. This species has been reported from both Thailand and Vietnam, including Phitsanulok Province in Thailand ( Zettel & Chen 1996). In this study, this species was collected from Kanchanaburi and Prachuap Khiri Khan provinces. Based on intensive observations in the field, both adults and nymphs were found frequently on the lee side of rocks in fast flowing streams, where the rocks provide a protected, less turbulent habitat. When they were pursued, they jumped off the rock and glided away, but returned to the same place after several minutes.

Material examined. THAILAND: Kanchanaburi Province: Amphur Thong Pha Phum, Heuy Pak Kog, 14º39'N 98º32'E, 184 m, 12-IV-2002, UMC and CMU teams, L-336 (6 males, 6 females); same locality, 8-IV-2003, Sites, Vitheepradit, Prommi, and Setaphan, L-455 (11 males, 7 females); Thong Pha Phum NP, Heuy Pak Kog, 14º38'N 98º31'E, 206 m, 9-IV-2003, Sites, AV, Prommi and Setaphan, L-460 (1 male, 2 females); Prachuap Khiri Khan Province: Amphur Kui Buri, Forest Plantation Station, 12º04'N 99º37'E, 117 m, 17-V-2002, Vitheepradit and Ferro, L-540 (1 male).

Figures

FIGURES 3 – 9. Taxa of Ptilomerinae. (3) Rheumatogonus intermedius, (4) Pleciogonus wongsirii, (5) Rhyacobates malaisei, (6) male Pleciobates pachalatkoi, (7) female Pleciobates pachalatkoi, (8) male Ptilomera tigrina, and (9) female Ptilomera tigrina.

FIGURES 38 – 42. Lateral view of left paramere of (38) Rheumatogonus vietnamensis, (39) Rheumatogonus intermedius, (40) Pleciobates pacholatkoi, (41) Pleciobates tuberculatus, (42) Pleciogonus wongsirii.

FIGURES 43 – 46. Terminal abdominal segments of species of female Pleciobates. P. pacholatkoi in (43) dorsal and (44) lateral view; P. tuberculatus in (45) dorsal and (46) lateral view.