Dilacreon (Eluzalmon) falcatus, Chen & Zhi, 2023

Chen, Xiang-Sheng & Zhi, Yan, 2023, Taxonomic study of the Eucarpiini (Hemiptera: Fulgoromorpha: Cixiidae) from China, Zootaxa 5347 (1), pp. 1-100 : 33

Dilacreon (Eluzalmon) falcatus sp. nov.

( Figs 19‒21 )

Description. Body length: male 5.1‒5.4 mm (n = 5), female 6.1‒6.5 mm (n = 8).

Coloration. General color grayish brown ( Fig. 19A–F ). Eyes blackish brown, ocelli light yellow, semitransparent. Vertex generally brown with lateral carinae yellowish brown. Face generally yellowish brown with lateral margins dark brown; rostrum yellowish brown. Pronotum and mesonotum brown with light yellow carinae. Forewing grayish brown, semi-translucent, veins darker; stigma dark brown. Hind tibiae and abdominal sternites yellowish brown.

Head and thorax. Vertex ( Figs 19C , 20A ) broad, 2.7 times wider than long; anterior margin slightly convex, median carina obsolete, posterior margin archedly recessed. Frons ( Figs 19D , 20B ) widest slightly below the level of antennae, 1.3 times as wide as long; frontoclypeal suture nearly concave into an arch; middle carina complete; lateral carinae distinct and slightly elevated. Pronotum ( Figs 19C , 20A ) 2.4 times longer than vertex; median carina indistinct, posterior margin nearly at right angle. Mesonotum 1.7 times longer than pronotum and vertex combined. Forewing ( Fig. 20C ) 2.7 times longer than wide, with 10 apical and 6 subapical cells; fork Sc+RP distad of fork CuA 1 +CuA 2, first crossvein r-m slightly basad of fork MP, RP two branches, MP with five terminals: MP 11, MP 12, MP 2, MP 3, and MP 4, fork MP 1 +MP 2 basad of fork MP 3 +MP 4. Metatibiotarsal formula: 6/7/8, second segment of hind tarsus with three platellae.

Male genitalia. Pygofer ( Fig. 20D, E ) symmetrical, dorsal margin concave and U-shaped, slightly widened towards apex in ventral view; in lateral view, lateral lobes triangularly extended caudally, medioventral process triangular in ventral view. Anal segment ( Fig. 20D, F ) broad, dorsal margin almost straight, apical half of ventral margin convex, apical lobes round in lateral view; 1.2 times longer than wide in dorsal view; anal style strap-shaped, slightly beyond anal segment. Gonostyli ( Fig. 20D, E, G ) symmetrical in ventral view; in inner lateral view, base of ventral margin slightly concave, dorsal margin bending inwards in a right-angle arc in the middle, apical part slightly extended, apical margin round. Aedeagus ( Fig. 20H–K ) with total of five processes. The ventral margin of periandrium with a slender spinous process near apex, relatively straight, apex ventrocephalically directed; left side in the middle with a very short spinous process, dorsocephalically directed. Endosoma (=flagellum) moderately sclerotised, medium-sized, generally dorsally curved. Base of right side with a long and broad falcate spinous process, which basal half pointed upward and then right-ventrocephalically directed. Left side with two spinous processes, one originated from base, left-cephalically directed, the other one on the apex, medium-sized, slightly curved and right-ventrocephalically directed.

Female genitalia. Posterior margin of pregenital sternite concave. Tergite IX ( Fig. 21A, D ) moderately sclerotised, 1.2 times longer than wide in caudal view. Anal tube ( Fig. 21A, C ) short, nearly rectangular, 1.4 times longer than wide in dorsal view; dorsal margin nearly straight and ventral margin slightly concave in lateral view, anal styles strap-shaped. Gonapophysis VIII ( Fig. 21E ) elongate, and slightly curved upwards. Gonapophysis IX ( Fig. 21F ) with one middle tooth, at a distance ratio, between middle tooth to apex and length of denticulate portion, of 1.8. Gonoplac ( Fig. 21G ) rod-like, 4.0 times longer than wide. Posterior vagina ( Fig. 21H, I ) elongate. The ventral wall of posterior vagina with three large sclerites, two nearly round at base and one long longitudinal sclerite in the middle aera; several small sclerites on the right distal half, elliptic or irregular in shape, arranged in an oblique row, and a nearly oval sclerite located on the left side of the queue. The dorsal wall with a long longitudinal large sclerite and a small elliptic sclerite on distal half.

Type material. Holotype: ♂, CHINA: Bakaxiaozhai (21°58’N, 101°13’E), Mengla County, Yunnan Province, 15 June 2016, leg. Ying-Jian Wang and Qiang Luo; paratypes: 3♂♂ 3♀♀, same data as holotye; 1♂ 5♀♀, Mohan Town, Mengla County , Yunnan Province, 20‒22 June 2016, leg. Ying-Jian Wang, Qiang Luo and Liang-Jing Yang.

Host plant. Unknown.

Distribution. China (Yunnan).

Remarks. Male genitalia of D. (E.) falcatus sp. nov. are similar to those of D. (E.) chionomus Fennah, 1980 , but differ in: (1) the ventral margin of periandrium with a spinous process (the latter without spinous process in the same position); (2) left side of periandrium at middle with a very short spinous process (the latter with one spinous process on dorsal margin and left side); (3) right side of endosoma with one spinous process (right side of endosoma with two spinous processes in D. (E.) chionomus ).

Etymology. The specific name refers to apex of right side of endosoma with a long and broad falcate spinous process.

Figures

FIGURE 19. Dilacreon (Eluzalmon) falcatus sp. nov., male. A. Habitus, dorsal view; B. Habitus, lateral view; C. Head and thorax, dorsal view; D. Face, ventral view; E. Head, lateral view; F. Hindwing. Scale bars: 0.5 mm.

FIGURE 20. Dilacreon (Eluzalmon) falcatus sp. nov., male. A. Head and thorax, dorsal view; B. Face, ventral view; C. Forewing; D. Genitalia, lateral view; E. Pygofer and gonostyli, ventral view; F. Anal segment, dorsal view; G. Gonostyli, inner lateral view; H. Aedeagus, right side; I. Aedeagus, left side; J. Aedeagus, dorsal view; K. Aedeagus, ventral view. Scale bars: 0.5 mm (A, B, D–K); 1.0 mm (C).

FIGURE 21. Dilacreon (Eluzalmon) falcatus sp. nov., female. A. Genitalia, lateral view; B. Genitalia, ventral view; C. Anal segment, dorsal view; D. Tergite IX, caudal view; E. Gonapophysis VIII and gonocoxa VIII, ventral view; F. Gonapophysis IX, lateral view; G. Gonoplac, lateral view; H. Posterior vagina, ventral view; I. Posterior vagina, dorsal view. Scale bars: 0.5 mm.