Dimorphocoris, FIEBER

Tatarnic, Nikolai J. & Cassis, Gerasimos, 2012, The Halticini of the world (Insecta: Heteroptera: Miridae: Orthotylinae): generic reclassification, phylogeny, and host plant associations, Zoological Journal of the Linnean Society 164 (3), pp. 558-658 : 593-596

DIMORPHOCORIS FIEBER ( FIGS 3 , 22–23 )

Dimorphocoris Reuter, 1890: 253 [gen. nov.; type species: Orthlocephalus signatus Fieber, 1861 subsequent designation (junior synonym of Phytocoris gracilis Rambur, 1839 )]; Reuter, 1891: 83, 159 (gen. nov., key); Hueber, 1906: 5, 6 (key, descr.); Kirkaldy, 1906: 131 (cat.); Oshanin, 1910: 784 (cat.); Reuter, 1910: 147 (cat.); Poppius, 1914: 85 (key, descr.); Bergevin, 1916: 61 (dimorphism); Stichel, 1933: 235 (key); Hedicke, 1935: 59 (key); Kiritshenko, 1951: 126 (key); Wagner, 1952: 96, 107 (key, descr.); Carvalho, 1952: 73 (cat.); Wagner, 1954: 221 (key to spp.); Carvalho, 1955: 67 (key); Carvalho, 1958: 8 (cat.); Lindberg, 1956: 56 (disc., key); Wagner, 1961: 50 (diag., key); Kerzhner, 1964b: 964 (diag., key); Wagner & Weber, 1964: 276 (syn., descr., key); Kerzhner, 1964a: 121 (key to spp. from USSR); Wagner, 1965a: 135 (disc., descr.); Wagner, 1965b: 57 (illustrated key); Wagner, 1969: 79 (modified key); Dimorphocoris (Pedetocoris) Kerzhner, 1970: 634 (subgen. nov., diag., disc., key); Wagner, 1973: 57 (descr., key); Linnavuori, 1992: 216 (key to lateralis group); Ehanno, 1994a: 10–37 (illustrated disc. of morphology, incl. MG, FG); Schuh, 1995: 48 (world cat.).

Homoeocoris Fuente, 1918: 236 (gen. nov. type species: Orthocephalus tristis Fieber, 1861 : syn. by Wagner, 1955: 241); Carvalho, 1958: 8 (cat.) Diagnosis: Recognized by the following combination of characters: female always brachypterous, male macropterous or brachypterous, macropterous individuals elongate and parallel-sided; body brown with yellow-brown and tan markings; frons, pronotum, and thoracic pleura with faint, symmetrical honeycombed texturing; eyes round and bulging, substylate to stylate; posterior margin of vertex with row of coarse black setae; endosoma with sclerites apparently originating from apex of secondary gonopore.

Redescription: Dimorphic, males macropterous or brachypterous, females brachypterous. Coloration ( Fig. 3 ): Highly variable, but generally a combination of dark brown to black with yellow, yellow-brown, or tan markings. Surface and vestiture ( Figs 3 , 22A–E, G, H ): body mostly smooth and impunctate, with some bilaterally symmetrical, honeycomb-like texturing on vertex, frons, pronotum and thoracic pleura, these patches sometimes congruent with contrasting colour patterning. Most of body densely covered with short, pilose setae, much less densely covered with longer simple and spine-like setae; sometimes also with long, silvery scale-like setae; posterior of vertex with a transverse row of coarse black setae; antennae and tibiae with short, semi-reclining bristle-like setae, AI typically with several longer, thicker bristles. Structure: head ( Figs 3 , 22A–D ): transverse, wider than tall; gena height equal or greater than eye height; frons mostly flat and sloping, sometimes with shallow medial sulcus continuing onto vertex; vertex sometimes with bilateral depressions adjacent to eyes, posterior margin of vertex straight, not upturned or carinate, weakly concave to weakly convex; eyes round and bulging, substylate to stylate, projecting laterally beyond and not touching anterolateral margins of pronotum, sometimes angled upwards. Antennae ( Figs 3 , 22B, C ): insertion in line with or below ventral margin of eye; long, thin, and cylindrical, always longer in males but generally not longer than body length; AI sometimes swollen, always longer than eye height; AIV shorter than AIII. Thorax ( Figs 3 , 22A, D, E ): pronotum campanulate in macropterous males, rectangular in brachypterous individuals, gently sloping to nearly level, collar thin, often obscured by strongly tumescent callosite region, posterior margin straight to concave; mesoscutum visible in macropterous males, steeply posteriorly declivent; scutellum often medially tumescent in macropterous males, broad and flat in brachypterous individuals; metathoracic spiracle prominent, diagonal, with evaporative bodies; MTG external efferent system tear-shaped, occupying posterior half of metepisternum, ostiole narrow and orientated ventrolaterally, peritreme elongate, weakly depressed, surrounded by narrow band of evaporative bodies. Hemelytra ( Fig. 3 ): Macropterous male: elongate, parallel-sided, cuneus long and thin; membrane with two cells, extends beyond tip of abdomen. Brachypterous: usually reduced to an undivided pad, sometimes with faint clavus. Legs ( Figs 3 , 22F ): long, particularly in macropterous males; pretarsi without pulvilli. Abdomen ( Fig. 3 ): elongate in macropterous males, elongate-oval to pear-shaped in brachypterous individuals. Male genitalia ( Figs 23A–C , 22G, H ): pygophore triangular in lateral view; left paramere L-shaped, sensory lobe rounded and weakly swollen, apophysis tapering, apex often hooked or weakly bifid; apex of right paramere angled and spoon- or hockey stick-shaped, apex sometimes with a small apophysis; aedeagus fully enclosed within phallotheca; ductus seminis elongate, with flexible ribbing; secondary gonopore sometimes cup-shaped, often weakly sclerotized and ill-defined, sometimes with scale-like texturing; endosoma with either complex, serrate, sclerotized outpocketings (lateralis group) or with single or paired sclerotized, pedunculate processes, often serrate, emanating from dorsal wall of secondary gonopore ( Dim. gracilis group). Female genitalia ( Fig. 23D, E ): sclerotized rings small, widely separated, mostly round to elongate-oval, lateral margins generally not curved upwards but lateral margin of adjacent portion of dorsal labiate plate typically upturned; posterior wall of bursa copulatrix variable, often divided into two bilaterally symmetrical regions of weak sclerotization, one anterior and one posterior, sometimes partly covered with fields of minute spines; vestibular opening symmetrical, with medial margins of first gonapophyses weakly swollen and weakly sclerotized.

Diversity and distribution: With 58 species this is the largest genus of Halticini . Dimorphocoris is found predominantly in the Mediterranean region but is also known to extend into North and East Africa, Central Asia, and Sakhalin Island in the North Pacific ( Ehanno, 1991, 1993, 1994a, b; Wagner, 1973; Linnavuori, 1992; Ehanno & Ribes, 1994). The genus is subdivided into two groups, the Dim. gracilis and Dim. lateralis groups.

Included species: Dimorphocoris abutilon Wagner, 1966 France

Dimorphocoris albipilis Kerzhner, 1964 Kazakhstan

Dimorphocoris alpinus Poppius, 1910 Kenya

Dimorphocoris argaeicus Hoberlandt, 1956 Turkey

Dimorphocoris asanovae Kerzhner, 1964 Palaearctic region (western)

Dimorphocoris atrans Kerzhner, 1970 Russia

Dimorphocoris beieri Wagner, 1965 the former Yugoslavia

Dimorphocoris bleusei Puton, 1898 Mediterranean

Dimorphocoris carayoni Ehanno & Ribes, 1994 France

Dimorphocoris cilix Seidenstücker, 1962 Turkey

Dimorphocoris concii Tamanini, 1972 Italy

Dimorphocoris constantini Ehanno, 1994a France

Dimorphocoris debilis ( Reuter, 1880) Mediterranean

Dimorphocoris distylus Seidenstücker, 1964 Turkey

Dimorphocoris dupuisi Ehanno, 1993a France

Dimorphocoris durfortae Ehanno & Ribes, 1994 Spain

Dimorphocoris eckerleini Wagner, 1965 Mediterranean

Dimorphocoris ehannoi Ribes & Ribes’ 2001 Morocco

Dimorphocoris fuscus Joakimov, 1909 * Palaearctic region (western)

Dimorphocoris gallicus Wagner, 1965 France

Dimorphocoris goulae Ehanno & Ribes, 1994 Spain

Dimorphocoris gracilis ( Rambur, 1839) * Algeria; Spain

Dimorphocoris josephinae Ehanno & Ribes, 1994 Spain

Dimorphocoris lateralis Reuter, 1901 Palaearctic region (western)

Dimorphocoris lividipennis Reuter, 1903 Spain

Dimorphocoris longiceps Wagner, 1968 Morocco

Dimorphocoris lurensis Wagner, 1957 France

Dimorphocoris marci Rizzotti Vlach, 1998 Italy

Dimorphocoris marginellus ( Puton, 1887) Algeria; Morocco

Dimorphocoris mariae Linnavuori, 1952 Mediterranean

Dimorphocoris matocqui Ehanno, 1993 France

Dimorphocoris mongolicus Kerzhner, 1970 Mongolia

Dimorphocoris mutatus Seidenstücker, 1964 Italy

Dimorphocoris obachi Ehanno & Ribes, 1994 Spain

Dimorphocoris osellai Tamanini, 1976 Italy

Dimorphocoris pedetes Kerzhner, 1964 Kazakhstan

Dimorphocoris pericarti Tamanini, 1972 France; Italy; Spain

Dimorphocoris poggi Carapezza, 2002 Italy

Dimorphocoris puigmalis Tamanini, 1976 France

Dimorphocoris punctiger ( Horváth, 1881) Israel; Syria

Dimorphocoris putoni ( Reuter, 1882) Andorra; France

Dimorphocoris pygmaeus Wagner, 1955 France

Dimorphocoris remanei Wagner, 1965 Spain

Dimorphocoris robustus Wagner, 1957 France

Dimorphocoris ruffoi Tamanini, 1971 Italy

Dimorphocoris sari Linnavuori, 1992 Greece

Dimorphocoris satyriscus ( Scott, 1870) Spain

Dimorphocoris saulii Wagner, 1965 Italy; Slovenia; the former Yugoslavia

Dimorphocoris schmidti ( Fieber, 1858) Ukraine

Dimorphocoris seidenstueckeri Linnavuori, 1984 Iraq

Dimorphocoris servadeii Tamanini, 1982 Italy

Dimorphocoris tamaninii Ehanno, 1993 France

Dimorphocoris tauricus ( Horváth, 1880) * Russia

Dimorphocoris tiberghieni Ehanno, 1993 France

Dimorphocoris tomasii Tamanini, 1971 Italy

Dimorphocoris toros Seidenstücker, 1962 Turkey

Dimorphocoris tristis ( Fieber, 1861) Spain

Dimorphocoris tuatayae Wagner, 1965 Morocco

Biology and host plant associations: Most species are thought to feed on grasses ( Wagner, 1973) with the majority of host records coming from the family Poaceae ( Table 1). Some species have also been collected from higher level angiosperms, with Dim. osellai collected from unidentified species of Lotus and Trifolium (Fabaceae) ( Tamanini, 1976), Dim. tristis found on Anthemis sp. (Asteraceae) ( Linnavuori, 1992), and Dim. seidenstueckeri collected from unidentified species of Asteraceae, Teurcrium (Lamiaceae) , and Trifolium (Fabaceae) ( Linnavuori, 1984) ( Table 1).

Many species, especially of the Dim. gracilis group, have restricted mountainous distributions, whereas others are more widely distributed in littoral meadows and on the grassy steppes of North Africa ( Wagner & Weber, 1964; Ehanno & Ribes, 1994). It is thought the restricted ranges of many species may be the result of the high degree of brachyptery expressed in the genus, particularly in females ( Linnavuori, 1992).

Remarks: Dimorphocoris is divided into two species groups: the Dim. lateralis group in which both sexes are brachypterous, and the Dim. gracilis group in which males are macropterous whereas females are brachypterous ( Linnavuori, 1992). Linnavuori (1992) further subdivided the former into three ‘phylogenetic subgroups’ (although no phylogenetic results were presented). The highly speciose Dim. gracilis group is also comprised of several distinct subgroupings, which are dealt with in detail by Ehanno (1993, 1994a, b) and Ehanno & Ribes (1994).

Members of the Dim. gracilis group are most similar in appearance and in genitalic form to the newly described monotypic genus Compositocoris Schwartz et al., 2008 : see appendix). In both cases the males are macropterous whereas the females are brachypterous, and the genitalia of both sexes are very similar. In particular, the presence of two paddleshaped sclerotized processes in the endosoma suggests a close relationship. Only the presence of apically stellate bristles on the body of the female and the structure of the posterior wall set Compositocoris apart. Although there is strong evidence to synonymize Compositocoris with Dimorphocoris , we refrain from doing so without examination of more specimens of Dimorphocoris .

Although we dissected few specimens of Dimorphocoris, Ehanno & Ribes (1994 ; Ehanno, 1994a, b) provide detailed illustrations of many species, including both male and female genital structure, which greatly assisted in informing this redescription.

Figures

Figure 3. Photographs of Halticini genera: Acratheus–Halticus. Abbreviations: F, female; M, male.

Figure 22. Scanning electron micrograph images of Dimorphocoris gracilis (male). A, head and pronotum, dorsal view; B, head and prothorax, ventral view; C, head, anterior view; D, head and thorax, lateral view; E, thorax, lateral view; F, tarsus; G, pygophore, ventral view; H, pygophore, lateral view.

Figure 23. Male and female genitalia of Dimorphocoris gracilis. A, aedeagus; B, left paramere; C, right paramere; D, bursa copulatrix, dorsal view; E, first gonapophyses, ventral view; F, posterior wall.