Chionomus Fennah 1971
Creators: name: Weglarz, Kathryn M.
name: Bartlett, Charles R
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Delphacidae
Chionomus

description: Key to males of the Genus Chionomus   
1. Armature of diaphragm distinctly bilobed (Figures 6i, 28a, 29a).............................................. (2).  
- Armature of diaphragm not distinctly bilobed, may be cordate, notched, or U-shaped (Figures 19a, 25a, 30a)........... (5).  
2. Armature of diaphragm hooked, lobes parallel; processes of segment X present but not particularly strong, specimens with carinae of the mesonotum lightened frequently forming a vitta (Figures 6, 22, 13, 28)............................. (3).  
- Armature of diaphragm not hooked, lobes distinctly diverging; processes distinct and directed ventrad, carinae of mesonotum concolorous (Figures 5, 21, 14, 29)..................................................................... (4).  
 3. Armature of diaphragm hooked only in apical half, lobes only diverging in apical half; aedeagus with toothed flange on left side (Figures 6, 22)............................................................................. C. bellicosus.   
 - Armature of diaphragm hooked along entire length, lobes diverging from point of origin; aedeagus without flange, with two rows of scattered teeth (Figures 13, 28)........................................................... C. pacificus.   
 4. Lobes of armature of diaphragm small and closely approximated; processes of segment X parallel. Posterior edge of pronotum dark, only paranota white in color (Figures 5, 21)................................................. C. banosensis.   
 - Lobes of armature of the diaphragm produced, diverging from point origin; processes of segment X diverging. Posterior edge of pronotum white, paranota also white (Figures 14, 29)............................................... C. puellus.   
 5. Pygofer with prominent quadrate, dorsolateral process. Parameres not flattened at apex. (Figures 12, 27)......... C. herkos.   
- Pygofer without dorsolateral processes, if produced at dorsolateral margin, not quadrate. Parameres flattened at apex. (Figures 19, 23, 26)......................................................................................... (6).  
6. Segment X with a total of 4 processes (Figures 23b, 24b, 25b, 30b)............................................ (7).  
- Segment X with only 2 processes or processes vestigial (Figures 19b, 20b, 26b, 31b)............................. (10).  
 7. Secondary processes of segment X small, spine-like. Armature of diaphragm shelf-like. Ventral margin of pygofer with caudally projecting median process (Figures 9, 24)..................................................... C. dolonus.   
- Secondary processes of segment X long, sinuate. Armature of diaphragm quadrate, quadrate and notched, or U-shaped. Ventral margin of pygofer lacking median process (Figures 23, 25, 29)............................................... (8).  
8. Armature of diaphragm quadrate or cordate/notched, toothed along vertical margins; aedeagus not distinctly enlarged at base (Figures 23a, c, 25a, c)............................................................................... (9).  
 - Armature of diaphragm U-shaped, lacking teeth; aedeagus with distinctly enlarged, quadrate base (Figures 29 a, b).............................................................................................. C. quadrispinosus.   
 9. Armature of diaphragm notched along ventral margin; aedeagus with slight enlargement apically. Parameres not produced opposite of basal angle. Posterior compartments of vertex and stem of Y-shaped carina dark (Figures 10, 25)... C. gluciophilus.   
 - Armature of diaphragm quadrate, notch along ventral margin not evident; aedeagus tapering along entire length, not enlarged apically. Parameres with rounded projection opposite of basal angle. Posterior compartment of vertex light but with fuscous markings, stem of Y-shaped carina light (Figures 8, 23)............................................. C. dissipatus.   
10. Aedeagus nearly straight, may have slight dorsal curve (Figures 19b, 20c, 26c)................................. (11).  
 - Aedeagus with distinct curve dorsad, nearly forming a right-angle apical hook on left, small teeth along length. Segment X with two rounded processes, lobe-like, arising from the middle of segment. Specimens frequently large for Chionomus, with wings infuscate (Figures 17, 31)......................................................................... C. tenae.   
 11. Aedeagus with subapical and distinctly projecting flagellum, lacking teeth and hooks (Figure 19b)............ C. havanae.   
- Aedeagus without flagellum, with hooks and/or teeth (Figures 20c, 26c)....................................... (12).  
 12. Aedeagus with large hooks on right side of aedeagus; apex of parameres anvil shaped (Figures 20b,c).......... C. balboae.   
 - Aedeagus with small teeth in two scattered rows, lacking any sort of hook; apex of parameres quadrate (Figures 26b,c)............................................................................................... C. haywardi.
description: Published as part of Weglarz, Kathryn M. & Bartlett, Charles R, 2020, A revision of the planthopper genus Chionomus Fennah (Hemiptera: Fulgoroidea: Delphacidae), pp. 1-63 in Zootaxa 4811 (1) on pages 10-11, DOI: 10.11646/zootaxa.4811.1.1, http://zenodo.org/record/3944031