Phibalothrips rugosus Kudo

(Figs 8–16)

Phibalothrips rugosus Kudo, 1979: 351 –353.

The genus Phibalothrips includes four species (ThripsWiki 2016): P. dispar zur Strassen from southern Europe, P. longiceps (Karny) from Australia to Pacific, P. rugosus Kudo from Southeast Asia, and P. peringueyi (Faure) from South Africa to Japan . P. rugosus was described from Kuala Lumpur, Malaysia, based on a single female collected from dry twigs, and is otherwise known only from one female that was collected from Pternandra sp. [ Melastomataceae] in Borneo (Kudo 1995). It is easily distinguished from its congeners by the strongly elevated ocellar region, abdominal tergites with widely spaced longitudinal reticles on lateral thirds, and the sternites of male without pore plates. The host plant of this species has remained unclear, but recently both sexes were collected from Pyllostachys sp. [ Poaceae] in Okinawa, southern Japan. The previously unknown male is described here.

Male macroptera. Distended body length about 1.3 mm. General body colour and structure almost as that of female, but abdominal segments II‒X completely light yellow (Fig. 9).

Head much longer than wide, clearly constricted at base; strongly irregular circular reticulate; ocellar region strongly elevated; cheeks fairly serrated; compound eyes projected forward (Fig. 10). Antennae (Fig. 11) 6-segmented, morphological segments VI and VII fused, segments III and IV with simple sensoria. Pronotum slightly shorter than wide, with tuberculate and rugose of sculpture (Fig. 10). Mesonotum irregularly hexagonal reticulate on anterior half (Fig. 12). Metascutum with elevated triangle of sculpture and faint hexagonal reticles. Metascutellum with faint hexagonal reticles. Abdominal tergite I, anteromedian half of II and lateral sides of VIII hexagonally reticulate (Figs 14‒15); lateral sides of tergites II‒VII tuberculate rather than rugose, weakly hexagonally and longitudinally reticulate; tergites II‒VIII smooth medially with broad median longitudinal ridges; tergite IX weakly sculptured; tergites II‒VII with S1 setae minute, S2 and S3 setae short and stout, S2 setae slightly stouter than S3, with two small setae at lateral margins; sternites III‒VII with setae arising in front of posterior margin and weakly hexagonally reticulate, without pore plate (Fig.16).

Measurements in microns. Head length 160, width across cheeks 117; compound eye dorsal length 63, width 45. Pronotal median length 143, width 165. Fore wing length 795, width at middle 38. Abdominal tergite IX median length 68, tergite X median length 48. Antennal segments I‒VI length (width) as follows: 23 (23), 30 (30), 83 (18), 70 (19), 48 (20), 60 (15).

Female macroptera. Distended body length about 1.5 mm. Body distinctly bicoloured (Fig. 8). Antenna, head, thorax for wing and abdomen colour similar to male.

Specimens examined. JAPAN (Ryukyus), Okinawa-prefecture, Naha City, Sueyoshi-park on Pyllostachys sp. [ Poaceae] (K. Minoura): 1 female, 19.xii.2004 ; 1 female, 10.iv.2005; 1 male, 19.iii.2008; 4 females, 17.xi.2010; 4 females, 22.xi.2010; 2 males, 25.x.2015; 1 male, 1.xi.2015.