Dayus Mahmood 1967
Creators: name: Qin, Dao-Zheng
name: Zhang, Ya-Lin
Publisher: name: Zenodo
Year: 2007
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Cicadellidae
Dayus

description: Genus Dayus Mahmood   
 Dayus Mahmood, 1967: 39.   
 Type species: Dayus elongatus Mahmood, 1967, by original designation.   
Mostly red and fragile species. Anterior margin of crown roundly protuberant and continuous with outer margin of eyes, posterior margin slightly concave, middle length of vertex equal to width between eyes. Coronal suture short and distinct. Face with anteclypeal and frontoclypeal areas swollen. Pronotum large. Scutoscutellar sulcus distinct. Forewing with apical cells occupying less than one-third its length, 2nd apical cell slightly broadening towards apex, 4th apical cell shortest; c and r cells equal in width, narrower than m and cua cells; veins RP, MP’ and MP ”+CuA’ arise from m cell. Hind wing with broad apical m cell and an area bordered by re-emerging AA and AP’ veins, small; CuA unbranched apically.  
Abdodminal apodemes well developed, divergent posteriorly. Pygofer elongate, strongly narrowing caudad, with rigid macrosetae on each side of pygofer lobe; dorsal margin produced with a rounded lobe-like structure usually with one or two rigid microsetae; ventral appendage present. Subgenital plate far exceeding pygofer side, broad at base, with macrosetae in basal group and laterally in one or two rows near middle portion. Paramere serrate apically, preceded by setae and sensory pits. Connective completely fused with the base of aedeagus. Aedeagal shaft compressed, gonopore apical, small; without preatrium and dorsal apodeme. Anal tube process broad, curved and narrowing apically with subapical ligament connection from dorsal margin.  
 Discussion. Dayus is related to Ifugoa Dworakowska & Pawar, Usharia Dworakowska, Baguoidea Mahmood and Goifa Dworakowska by the posteriorly divergent abdodminal apodemes; and connective fused with the base of the aedeagus. It differs from Ifugoa & Usharia by the forewing veins RP, MP’ and MP”+CuA’ all arising from the m cell and the subgenital plate with macrosetae in a basal group. From Baguoidea it differs in having the subgenital plate with a row of macrosetae subapically rather than a cluster of macrosetae and from Goifa by the pronotum being longer than the crown, the c and r cells of the forewing equally wide and the subgenital plate with macrosetae in a basal group, with macrosetae rather than fine microsetae laterally, and the inner margin without small fine setae.   
 Mahmood (1967) in his original description of the genus states that “This genus has characters in common with Empoasca but differs in the absence of an anal hook.” However, based on examination of the specimens of Dayus deposited in NWAFU and in CAU; and the illustrations of Dayus species described by Dworakowska (1971) and Dworakowska & Viraktamath (1978), all species have anal tube process. A similar situation occurs in the genus Homa Distant redescribed by Mahmood (1967); this genus also has anal tube process.   
 Dworakowska (1971) transferred Homa upoluana Osborn (1934), described from Samoa, to Dayus as a new combination based on the original description. The male genitalia of this species have not been examined or illustrated, but this species differs from those included here in coloration (ivory white in D. upoluana, red in the Chinese species), the body length (1.75 mm in D. upoluana, 3.0– 4.2 mm in males of the Chinese species), and the vertex length (in D. upoluana longer than the pronotum, shorter than the pronotum in the Chinese species).
description: Published as part of Qin, Dao-Zheng & Zhang, Ya-Lin, 2007, Revision of the Chinese species of the leafhopper genus Dayus Mahmood (Hemiptera: Cicadellidae: Typhlocybinae: Empoascini), with description of three new species, pp. 43-51 in Zootaxa 1624 (1) on pages 43-44, DOI: 10.11646/zootaxa.1624.1.4, http://zenodo.org/record/5103282