Stenotus Jakovlev, 1877

Namyatova, Anna A., Schwartz, Michael D. & Cassis, Gerasimos, 2013, First record of the genus Stenotus Jakovlev from Australia, with two new species, and a list of mirine species from Witchelina Nature Reserve (Insecta: Heteroptera: Miridae: Mirinae: Mirini), Journal of Natural History (J. Nat. Hist.) 47 (13 - 14), pp. 987-1008 : 989-994

Genus Stenotus Jakovlev, 1877

( Figure 1 )

Oncognathus Fieber, 1858: 303 (junior homonym of Oncognathus Lacordaire, 1854 , Coleoptera ; synonymized by Reuter, 1896: 122). Type species by monotypy: Lygaeus binotatus Fabricius, 1794

Stenotus Jakovlev, 1877: 288 . Type species by monotypy: Stenotus sareptanus Jakovlev, 1877 (= Lygaeus binotatus Fabricius, 1794 )

Umslopogas Kirkaldy, 1902a: 254 (synonymized by Poppius, 1910: 36 and Reuter, 1910: 160). Type species by monotypy: Umslopogas nigroquadristriatus Kirkaldy, 1902

Zulaimena Kirkaldy, 1902a: 256 (synonymized by Poppius, 1910: 36 and Reuter, 1910: 160). Type species by monotypy: Zulaimena hathor Kirkaldy, 1902

Korasiocapsus Kirkaldy, 1902a: 260 (synonymized by Reuter, 1907: 10). Type species by monotypy: Korasiocapsus pylaon Kirkaldy, 1902

Makua Kirkaldy, 1902b: 282 (synonymized by Poppius, 1912: 60). Type species by monotypy: Makua psole Kirkaldy, 1902

Nymannus Distant, 1904a: 195 (synonymized by Carvalho, 1981: 5). Type species by original designation: Nymannus typicus Distant, 1904

Tancredus Distant, 1904b: 430 (synonymized by Poppius, 1911: 16). Type species by original designation: Tancredus sandaracatus Distant, 1904

Indoelum Kirkaldy, 1906: 138 (synonymized by Distant, 1910: 240, with Tancredus ). Type species by original designation: Megacoelum rubricatum Distant, 1904

Elthemus Distant, 1909: 451 (synonymized by Chérot, 2000: 38). Type species by subsequent designation ( Distant, 1910: 243): Elthemus conspicatus Distant, 1909

Diagnosis

Distinguished from other Australian Mirini by the hind tarsus with segment I distinctly longer than segment II and subequal to segment III ( Figure 3A, B ); body size usually greater than 5 mm; hemelytra not transparent, abdomen and legs not visible through hemelytra; costal margin subparallel-sided; dorsal surface slightly shining and wrinkled, lacking punctation; claval and anal veins without homogeneous lines of large and deep punctures; dorsal vestiture consisting of moderately dense, short adpressed, pale simple setae and sparse sericeous setae near the claval suture; head about as long as wide or wider than long with clypeus not pointed dorsally ( Figure 2B, C ), vertical in lateral view ( Figure 2E, F, H ); and transverse basal carina of vertex absent ( Figure 2B, C ). Globally Stenotus is distinguished from all other genera of Mirini, except Zalmunna Distant, 1909 , by the long first segment of the hind tarsus. The roughly similar dimensions of the head and rounded clypeus of Stenotus contrast with Zalmunna where the head length is much greater than the head width and the clypeus is distinctly pointed and is practically horizontal in lateral view. Externally two Asian bamboo-associated genera, Azumamiris Yasunaga, 2010 and Elthemidea Zheng, 1992 (Yasunaga 2010, Zheng 1992, Zheng, et al. 2004), have a superficial resemblance to Stenotus . However, in both genera the structure of the hind tarsus and the genitalia of both sexes are significantly different from Stenotus . The first tarsal segment is shorter than the second segment, the endosoma includes a long spicule attached ventral to the secondary gonopore, and the inter-ramal sclerite includes lateral lobes. In species of Stenotus the first tarsal segment is longer than the second, the endosoma lacks a conspicuous spicule, and the inter-ramal sclerite lacks lateral lobes.

Description of genitalia

Male genitalia. Genital capsule ( Figures 3D, E , 4E, J , 5E ): slightly turned left relative to pregenital segments; ventral surface acute apically with length relative to dorsal surface variable; without tubercles dorsal to paramere insertions.

Right paramere ( Figures 4B, G , 5B ): shape variable. Left paramere ( Figures 4C, D, H, I , 5C, D ): C-shaped, wide basally, sometimes sensory lobe developed; apex variably hooked.

Aedeagus: in repose only slightly longer than left paramere, length variable, 0.75–1.25; fully inflated endosoma variable, usually always with variously developed membranous lobes and without distinct spicules originating ventral to secondary gonopore; sometimes with variable distal sclerotized plates on membranous lobes (cf Kelton 1959: 61, fig. 35); sometimes with left half of endosoma weakly sclerotized; sometimes with four lobes ( Figures 4A, F , 5A ) – two medial and two lateral – each lobe with variably distributed fields of spicules and varying length and orientation; ductus seminis only slightly longer than phallotheca, divided into three parts, proximal and distal parts sclerotized, medial part with membranous rings; aperture of secondary gonopore wide, sclerotized with coil-like structure.

Female genitalia. Dorsal labiate plate ( Figures 6A–C ): sclerotized rings generally small, subovoid or somewhat elongate, widely separated, separated by distance equal to two to four times longest dimension of ring. Dorsal labiate plate variably sclerotized adjacent to rings, medially membranous; seminal receptacle large, broadly joining common oviduct; ventral labiate plate entirely membranous.

Vestibulum: faintly sclerotized medially between first gonapophyses; first gonapophyses sclerotized on anterior surface.

Posterior wall ( Figure 6D–F ): inter-ramal sclerite weakly sclerotized laterally, merging with mostly membranous median process, median process tumid posteriorly; distance between inter-ramal lobes variable, ventral margin of lobe not reaching midpoint of inter-ramal sclerite; dorsal structure variably membranous, tumid anteriorly; dorsal lobe present or absent, lateral lobes absent.

Discussion

Stenotus is an Old World genus containing 52 species with the majority (approximately 70%) distributed in the Ethiopian region. The presence of S. binotatus in the Nearctic region is presumed to be an accidental introduction ( Wheeler and Henry 1992). The preceding description of the endosoma in Stenotus is based on a small sample of identified African species [ Stenotus hathor (Kirkaldy, 1902) (00110300), Stenotus nigroquadristriatus (Kirkaldy, 1902) (00110303), Stenotus proitos Linnavuori, 1974 (00110294), Stenotus pylaon (Kirkaldy, 1902) (00110298), Stenotus subglaucus (Wagner, 1974) (00110291), Stenotus transvaalensis (Distant, 1904) (00110297), and Stenotus vitticollis Reuter, 1907 (00110299)] and unidentified specimens from New Guinea ( Stenotus spp. : 00110308, 00110309, 00110311). The two new Australian species belong to a group, including the type species S. binotatus , in which the aedeagus is large and the endosoma has four variable membranous lobes. Of the extralimital specimens S. pylaon , S. transvaalensis and S. vitticollis also have this aedeagal structure. Of the remaining Stenotus species examined, S. nigroquadristriatus and S. proitos have a large aedeagus and a lobe of the endosomal membrane is long and subtended by a sclerotized plate. The aedeagus is smaller and the left side of the endosoma is smoothly sclerotized in three unidentified New Guinea Stenotus specimens, S. hathor and S. subglaucus . Whether these three forms of endosomal structure define monophyletic groups within Stenotus is beyond the scope of the current project. Based on our small sample of Stenotus species we strongly concur with Linnavuori (1975) in suggesting that the genus should be revised, because of the absence of a comprehensive identification key to species and the limited knowledge of the genital structures of most Stenotus species.

Figures

Figure 1. Habitus view of Stenotus gressitti, Stenotus witchelina and Stenotus binotatus (male and female of each species).

Figure 2. Scanning electron micrographs. Stenotus gressitti: (A) head of male, anterior view; (B) head and pronotum of male, dorsal view; (E) head and pronotum of female, lateral view; (I) vestiture on hemelytra. Stenotus witchelina: (C) head and pronotum of male, dorsal view; (D) head of male, anterior view; (F) head and pronotum of female, lateral view; (G) head of female, anterior view; (H) head of female, lateral view.

Figure 3. Scanning electron micrographs. Stenotus gressitti: (A) hind tarsus; (C) pretarsus, lateral view; (D) abdomen, lateral view; (F) pretarsus, dorsal view; (G) pretarsus, ventral view; (H) evaporatorium. Stenotus witchelina: (B) hind tarsus; (E) abdomen, lateral view; (I) evaporatorium.

Figure 4. Male genitalia. Stenotus gressitti: (A) inflated aedeagus, dorsal view; (B) right paramere, dorsal view; (C) left paramere, posterior view; (D) left paramere, dorsal view; (E) genital capsule, dorsal view. Stenotus witchelina: (F) inflated aedeagus, dorsal view; (G) right paramere, dorsal view; (H) left paramere, posterior view; (I) left paramere, dorsal view; (J) genital capsule, dorsal view.

Figure 5. Male genitalia. Stenotus binotatus: (A) inflated aedeagus, dorsal view; (B) right paramere, dorsal view; (C) left paramere, posterior view; (D) left paramere, dorsal view; (E) genital capsule, dorsal view.

Figure 6. Female genitalia. Stenotus gressitti: (A) dorsal labiate plate; (D) posterior wall of bursa copulatrix. Stenotus witchelina: (B) dorsal labiate plate; (E) posterior wall of bursa copulatrix. Stenotus binotatus: (C) dorsal labiate plate; (F) posterior wall of bursa copulatrix.