Nysius Dallas in Mongolian Plateau, 1852

Ge, Xinyu & Li, Junlan, 2019, Review of the genus Nysius Dallas from Mongolian Plateau (Hemiptera: Heteroptera: Orsillidae), Zootaxa 4560 (1), pp. 171-183 : 182

Key to species of genus Nysius Dallas in Mongolian Plateau

1. Buccula gradually tapering toward distal end; metatarsus with first segment longer than the second and third segments combined............................................................................................... 2

- Buccula not tapering posteriorly, basal and distal ends with equal height; metatarsus with first segment shorter than or equal to second and third segments combined...................................................................... 6

2. Scutellum without conspicuous carina..................................................................... 3

- Scutellum with conspicuous carina........................................................................ 5

3. Corium testaceous, nearly translucent, without dark macula, lateral corial margin not conspicuously arched; scutellum with long decumbent hairs....................................................................... N. graminicola

- Corium yellow, scattered with some dark maculae, lateral corial margin conspicuously arched; scutellum with short decumbent hairs................................................................................................ 4

4. Buccula with distal end sharpened or somewhat blunt; first segment of rostrum commonly exceeding or reaching end of buccula.................................................................................... N. ericae ericae .

- Distal end of buccula blunt; first segment of rostrum usually shorter than buccula........................ N. thymi thymi

5. Scutellum with a dark brown carina; corium opaque and with scattered dark maculae, lateral margin conspicuously arched and basally with decumbent hair..................................................................... N. eximius

- Scutellum with a flavescent carina; corium nearly translucent, and lateral margin not conspicuously arched..... N. helveticus

6. Metatarsus with the first segment equal to second and third segments combined.......................... N. nigricornis

- Metatarsus with the first segment shorter than the second and third segments combined.............................. 7

7. Color of the second and third segments of antenna variable, from aureus to dark, and with erect hairs; present in high altitude area of Mongolia............................................................................. N. pilosulus

- Second and third segments of antenna testaceous, with semi-erect hairs; present in western desert area of Inner Mongolia and Mongolia.................................................................................. N. senecionis