Megacoelum Fieber, 1858

Chérot, F. & Malipatil, M. B., 2016, A review of Adelphocoris - Creontiades - Megacoelum complex (Hemiptera: Heteroptera: Miridae: Mirini), with descriptions of two new genera and four new species, Zootaxa 4126 (2), pp. 151-206 : 169

10. Megacoelum Fieber, 1858

( Figures 29–32, 33 )

Megacoelum Fieber, 1858: 305 (as new genus) [type-species by monotypy: Megacoelum infusum (Herrich-Schaeffer, 1839) ]. Megacoelum third palearctic species group sensu Linnavuori, 1974: 27 .

Diagnosis. Body sub-oblong, slightly convex, total length 5–8, uniformly stramineous or orange brown, sometimes with fine red or brown stripes or red brown areas ( Figs 29–33 ). Head regularly sloping anteriorly, in profile frons not protruding and devoid of a notch above tylus, tylus regularly curved ( Linnavuori 1974a, b); labium reaching middle or hind coxae; first antennal segment weakly club-like, elongate and curved; pronotum dorsally almost glabrous, with a dull, narrow collar and a pair of stiff erect setae on anterior corners; scutellum relatively flat, slightly tumid; pilosity of metafemora erect and shorter than width of femora; tibial spines dark brown to black; hemelytra slightly reflective, frequently translucent, their punctation double, one very reduced, dense, narrow and shallow, the second shallow but larger, their pilosity, when present, reduced, short, sparse, simple, recumbent, sometimes hemelytra almost glabrous; veins raised; secondary gonopore complete, devoid of sclerite, hairs or pilose plate, phallus devoid of comb or phallic support, always with several fields of denticles and an apical true spiculum, generally pointed, sometimes hooked. Parieto-vaginal rings reduced, narrow, totally separated, devoid of a pair of anterior projections; dorso-labiate plate reduced, thin and elongate. Dorsal process of posterior wall absent, median process absent, interramal sclerites (A-structures) and interramal lobes (E-structures) developed.

Included species. M. formosanum Poppius, 1915 *, M. infusum Herrich-Schaeffer, 1837 *, M. myrti Linnavuori, 1965 , M. oculare Wagner, 1957 *, M. pellucens Puton, 1881 , M. rubrolineatum Linnavuori, 1975 *, M. salsolae Linnavuori, 1986 *, M. sordidum Reuter, 1904 *, M. tricolor Wagner, 1958 , M. zollikoferiae (Lindberg, 1953) *.

Distribution. Canary Islands, China (Guandong, Guangxi, Hainan, Yunnan), Europe, Egypt, Iran, Israel, Saudi Arabia, Syria, Sudan, Turkey, Yemen.

Host plants. Asteraceae, Betulaceae, Chenopodiaceae, Fabaceae, Fagaceae, Myrtaceae, Polygonaceae, Rosaceae, Tamaricaceae.

Discussion. Linnavuori (1974b) divided the west Palearctic species of the genus Megacoelum into three species-groups. Some species presently classified in Megacoelum should be actually included in another genus of the complex. According to our new diagnosis of the genus, true Megacoelum are the species included by Linnavuori in his group three. M. pelluscens was accommodated in its own species-group (group one) by Linnavuori (op. cit.) on the basis of the length and the coloration of its antenna. However, the species shares other character states with true Megacoelum . Consequently, we tentatively include it in this genus. M. superbum Linnavuori, 1975 , from Sudan, could belong to true Megacoelum , but is unknown to us, was described on females alone and should be analysed more in details to confirm its generic placement, like several Afrotropical species described by Poppius (1912). M. brevirostre Reuter, 1879 from Near East and Middle Asia is unusual by its habitus, coloration and vesical structure (particularly the presence of a phallic support and a comb). This species, known to us just by literature, should be reclassified in another genus, maybe in the genus Reuterista Kirkaldy, 1904. The other west Palearctic species of Megacoelum were classified by Linnavuori (1974b) in his group two. We suggest they constitute a separate new genus— Pseudomegacoelum Chérot & Malipatil n. gen. —described below. According to the description of its phallus by Pathak (1969: 55, pl. V, Fig. 3 ), “ M. ” esmedorae Ballard, 1927, described from India (Coimbatore), should be placed in another genus. Some still undescribed Australian species have similar phallus. Finally, several Indian and other Oriental species originally described as Megacoelum are transferred in this publication to genera Orientomiris Yasunaga, 1997 , Poppiocapsidea Yasunaga, 1998 and Waucoris Carvalho, 1987 .

Figures

FIGURES 28 – 35. Habitus of ACMc members: 28. Gollneria quadrituberculatum nomadicum Linnavuori, 1975, female holotype from South Sudan (AMNH). 29. Megacoelum formosanum Poppius, 1915, male lectotype from Taiwan (MZHF). 30. Megacoelum infusum Herrich-Schaeffer, 1837, a specimen from France (MNHN). 31. Megacoelum salsolae Linnavuori, 1986, male holotype from Saudi Arabia (AMNH). 32. Megacoelum zollikoferiae (Lindberg, 1953), male paratype from Fuerteventura, Canary Islands (MNHN). 33. “ Megacoelum ” esmedorae Ballard, 1927, female holotype from Coimbatore, India, a species remaining to reclassify, probably in a genus still to describe (NHM). 34. Neomegacoelum vitreum (Kerzhner, 1988), a male from Japan (USNM). 35. Neopeplus trianai Malipatil, Chérot & Schwartz in Chérot, Malipatil & Schwartz, 2003, female paratype from Australia (SAM). Scales = 1 mm.

FIGURES 1 – 8. Habitus of ACMc members: 1. Adelphocoridea brunnea Poppius, 1912, male from Madagascar (MNRJ). 2. Adelphocoridea laevigata Poppius, 1912, female holotype from Madagascar (MZHF). 3. Adelphocoris seticornis (Fabricius, 1775) from Belgium. 4. Adelphocorisella brunnescens (Poppius, 1915) n. comb., male holotype from Papua New Guinea (MZHF). 5. Adelphocorisella relata (Distant, 1904) n. comb., male lectotype from Sri Lanka (NHM). 6. Adelphocorisella rubricornis n. sp., female holotype from Australia (ANIC). 7. Carvalhocapsus scutellosum (Carpintero & Chérot, 2002), male paratype from Argentina (Coll. D. L. Carpintero). 8. Cheilocapsidea insignis (Distant, 1909), male from Laos (NMPC). Scales = 1 mm.