Ptilomera jariyae Vitheepradit & Sites

Figs. 16, 17, 30, 31

Ptilomera jariyae Vitheepradit & Sites 2007: Ann. Entomol. Soc. Am. 139–142.

Diagnosis. Ptilomera jariyae males can be recognized by the well-developed median lobe of the proctiger (Figs. 16, 17), and females by the absence of a ventrolateral lobe of abdominal segment VII (Figs. 30, 31). More specifically, males of P. j a r i y a e can be distinguished by the median lobe of the proctiger well surpassing the posterior tips of the lateral wings (Fig. 16), whereas it is more or less even with the posterior tips of the lateral wings in P. tigrina (Fig. 22), and by the pygophore with a roundly triangular apex (Fig. 17), which is narrowly digitate in P. tennaserim (Fig. 21). Females of P. j ar i y ae can be distinguished by stout, divergent connexival spines with a sharp basal inflection (Fig. 30), whereas both regional congeners have elongate, convergent connexival spines (Figs. 34, 36).

Discussion. This species was previously reported from shaded, gravel-bottomed parts of streams in Kanchanaburi, Phetchaburi and Prachuap Khiri Khan provinces (Vitheepradit & Sites 2007). Most specimens occurred on the water surface on the lee side of emergent rocks in shaded parts of the stream near the margin where there was less turbulence (Vitheepradit & Sites 2007). When they were pursued, they tended to swim upstream; however, they seemed not to be able to skate on the water surface as well as did P. tigrina (Vitheepradit & Sites 2007) . Moreover, they appeared to return to occupy the same place they were before they were pursued (Vitheepradit & Sites 2007). P. j a r i y a e can be distinguished in the field by its reddish brown color, whereas P. tigrina is relatively dark brown, and P. jariyae seemed to be much less abundant than was P. tigrina .

Material examined. THAILAND: Kanchanaburi Province: Amphur Thong Pha Phum, Heuy Ka Yaeng at Ban Pasadoo Klang, 14º33'N 98º34'E, 296 m, 26-V-2004, Vitheepradit and Prommi, L-717 (9 males, 9 females); same locality, 9-IV-2003, Sites, Vitheepradit, Prommi and Setaphan, L-457 (3 males, 9 females); same locality, 4- VI-2006, Sites, Vitheepradit and Prommi, L-915 (2 males, 2 females); Thong Pha Phum NP, Jog Kradin Waterfall, 14º41.170'N 98º22.890'E, 661 m, 25-XI-2006, KU team, C-5 (1 male); Phetchaburi Province: Kaeng Ka Chan NP, stream at Ban Krang, 12º48'N 99º26'E, 380 m, 28-V-2004, Vitheepradit and Prommi, L-721 (7 males, 2 females); same locality, 20-V-2012, KU team, C-154 (5 females); Prachuap Khiri Khan Province: Kaeng Ka Chan NP, Pa La Ou Waterfall, 12º32'N 99º27'E, 319 m, 28-V-2004, Vitheepradit and Prommi, L-722 (3 males, 1 female); same locality, 21-I-2013, KU team, C-255 (1 male, 1 female).