Hishimonus Ishihara

Dai, Wu, Fletcher, Murray J. & Zhang, Yalin, 2013, First records of the genus Hishimonus Ishihara from Thailand (Hemiptera: Cicadellidae: Deltocephalinae: Opsiini) including description of three new species, Zootaxa 3670 (3), pp. 301-316 : 302-303

Hishimonus Ishihara

Hishimonus Ishihara 1953: 38 . Type species Thamnotettix sellatus Uhler, 1896 , by original designation.

Description (modified from Knight 1970a). Small species, 3–4 mm in length, testaceous, greenish or yellow in colour, often marked with brown, legs and venter stramineous, forewings silvery white with dark brown mottling and usually with a large brown semicircular spot against midlength of commissural margin forming, when wings at rest, a conspicuous circular spot with that of opposite wing. Head equal in width to pronotum, slightly longer medially than next eye with anterior margin broadly rounded; narrowly rounded to face; frontoclypeus longer than wide; clypeal suture distinct; anteclypeus elongate with sides parallel over basal two thirds, slightly expanded at apex; genal margins concave beneath eyes; ocelli on anterior margin, contiguous with eyes or separated by distance less than own diameter; a shallow transverse furrow on vertex between ocelli; vertex posterior to furrow glabrous, face and vertex anterior to furrow shagreened. Pronotum approximately twice length of vertex, sides short, posterior margin transverse or shallowly concave; surface glabrous, transversely and feebly striate. Scutellum wider than long, slightly shorter than pronotum. Forewings with claval veins separate, a cross vein near midlength; inner subapical cell open basally; outer subapical cell elongate with ends transverse; appendix well developed. Fore femur with setae distributed as follows: 2 AD at apex, well developed AM1, 9–13 ic, 6–8 PV and 12–13 short AV. Fore tibia with setae distributed as follows: 4 AD evenly spaced along length with black spot at base of each, single PD near apex and continuous line of PV extending throughout length. Apex of hind femora with setal formula 2.2.1. Male genitalia with pygophore acutely rounded posteriorly, with stout setae over posterior half, without processes, dorsal surface approximately one third total length; subgenital plates gradually or abruptly tapering posteriorly to membranous fingerlike process, with uniseriate row of stout setae laterally, becoming multiseriate basally, with more lateral row of long filamentous setae over apical half; connective Y-shaped with stem long or short; paramere terminating in posteriorly directed fingerlike process, preapical lobe present; aedeagus with two dorsally directed shafts each with gonopore near apex, with or without basal processes, usually with apical or preapical processes on shaft.

Comments. The species of Hishimonus can usually be identified by the presence of the distinctive circular brown marking dorsally in the centre of the folded tegmina and the processes associated with the aedeagus. The dorsal forewing patch may be ill-defined in some individuals and appears to be undefined in H. pallidus sp. nov. Knight (1970b), in defining the two genera Naevus and Litura , differentiated them from Hishimonus on the basis that the atrium of the aedeagus not extended ventrad of the shafts. Litura was further differentiated from Hishimonus on the basis that the subgenital plates narrow abruptly to the posterior finger-like process in Litura but are more tapered in Hishimonus and Naevus . In addition, Naevus has the male pygophore broadly rounded posteriorly rather than acutely rounded as in Hishimonus and Litura . From Hishimonoides , Hishimonus can be differentiated by the absence of a pair of well-developed ventral paraphyses on the aedeagus. The distinction between Hishimonus and Hishimonoides was discussed by Singh (1971) who concluded that the latter was a synonym of Cestius Distant and the former constituted a subgenus of Cestius . This was rejected by Knight (1973) on the basis that Cestius was externally quite different from what he termed the “ Hishimonus group” which comprised Hishimonus , Hishimonoides , Litura and Naevus .

In all the Thai species of Hishimonus except for H. subtilis , the two aedeagal shafts lack a pair of processes anterior to the bases of the shaft but they have processes more closely associated with the shafts themselves, often fused with them for part or all of their length. Apically the gonopores are preapical with the apex of the shafts often extended to form processes of various forms.