16. Genus Echthrodelphax R. Perkins, 1903

Echthrodelphax R. Perkins 1903: 36; Kieffer in Kieffer & Marshall 1906: 489, 493; Kieffer 1914b: 16; Richards 1939: 188; Chandra 1980c: 192; Olmi 1984: 1140; Olmi 1993b: 78, 79; Olmi 1995g: 5; Olmi 1996b: 179; Olmi 1999a: 220; He & Xu 2002: 300; Moya-Raygoza & Olmi 2010: 99.

Pterogonatopus Abdul-Nour 1976: 275 (synonymized by Olmi, 1984); type species: Pterogonatopus hortusensis Abdul-Nour 1976, by monotypy.

Type species. Echthrodelphax fairchildii R. Perkins, 1903, by monotypy.

Diagnosis. Female: fully winged (Plate 100A, B); rarely brachypterous (only in one specimen of E. rufus Olmi from China, Guangdong, Yunjishan Nature Reserve); palpal formula 3/2, 4/2, 5/2, 5/3, or 6/3; antenna with rhinaria; pronotum crossed by strong transverse furrow (Plate 100A); notauli complete (Plate 100A); enlarged claw with one subapical tooth and one row of lamellae (Plates 100C, 102C, D); segment 5 of protarsus with less than 15 medial lamellae (Plates 100C, 102C, D); tibial spurs 1/0/1. Male: fully winged (Plate 101A, B); head with distinct complete occipital carina; occiput concave; temple present; palpal formula 3/2, 4/2, 5/2, 5/3, or 6/3; tibial spurs 1/ 1/2.

Distribution. Worldwide.

Hosts. Delphacidae (Guglielmino & Olmi, 1997, 2006).

World species. Twelve species are known, three in the Oriental region.

Key to the species

Females

1. Fore wing with two brown transverse bands; body completely testaceous, with petiole black and metasoma darkened................................................................................................. E. rufus Olmi

- Fore wing hyaline, without dark transverse bands, or with one brown transverse band; mesosoma partly black............ 2

2. Scutum black; ocellar triangle usually without median keel, rarely with incomplete median keel..... E. fairchildii R. Perkins

- Scutum testaceous-reddish; ocellar triangle with complete median keel.............................. E. laotianus Olmi

Males

1. Notauli complete, posteriorly joint; dorsal process of paramere pointed, short, distinctly developed (Plate 102A); labial palpi 2- segmented......................................................................... E. fairchildii R. Perkins

- Notauli complete, posteriorly distinctly separated; dorsal process of paramere fold-shaped (Plate 102B, E, F); labial palpi 3- segmented........................................................................................... 2

2. Fold of paramere strongly developed (Plate 102B); paramere without sense organs (Plate 102B).......... E. laotianus Olmi

- Fold of paramere less developed (Plate 102E, F); paramere with numerous sense organs (Plate 102F)......... E. rufus Olmi