Macromalthinus guyanensis, Biffi & Constantin, 2018

Biffi, Gabriel & Constantin, Robert, 2018, A revision of Macromalthinus Pic, 1919 with description of six new species (Coleoptera: Cantharidae: Chauliognathinae), Papéis Avulsos de Zoologia (Pap. Avulsos Zool., S. Paulo) 58, pp. 1-22 : 17-18

Macromalthinus maximiceps Pic, 1919 ( Fig. 52 , 55-58 )

Macromalthinus maximiceps Pic, 1919: 15 ; Delkeskamp, 1939: 215; Blackwelder, 1945: 369; Delkeskamp, 1977: 467; Brancucci, 1981a: 260; Constantin, 2010a: 41; Constantin, 2010b: 25; Constantin, 2016: 27.

Material examined: LECTOTYPE ♂: [ FRENCH GUIANA] St. Jean du Maroni , collection Le Moult ( MNHN) ( Fig. 52 ) . Other specimens: FRENCH GUIANA. Cayenne, Alicoto- Oyapock, 13.xi.1969, ‘piège lumineux’ (Guyane Mission Balachowsky-Gruner) (1 ♂ NHMB) ; 30 km S Cayenne, Crossroad N1/D5, XII.2002 -2003, Michael Balke (1 ♀ BMNH 2004-46 ) ; Roura , Kaw Rd., 27 km SE, MV light, 21.IV.2007, J.E. Eger coll. (1 ♀ FSCA) ; idem, 6 km W Montagne des Chevaux , 04°45’N, 52°27’W, 75 m, 05.IX.2015, PVB, P.H. Dalens, F. Robin, F. Sonzogny leg. (1 ♂, 1 ♀ MZSP, 1 ♀ CCo) ; idem, 11.VII.2009, PV (1 ♂ CCo) ; idem, 20.VIII.2009, PL (1 ♀ CCo) ; idem, 06.XII.2009, PV (2 ♀ CCo) ; idem, 03.V.2010, PV (2 ♀ CCo) ; idem, 01.II.2011,PV(1♂ CCo) ; idem, 10.VI.2012, PV (1 ♀ CCo) ; idem, 08.VII.2012, Slam, (1 ♂ CCo) ; idem, 20.VII.2013,PVB (2 ♀ CCo) ; idem, 21.IX.2013, Slam (1 ♀ CCo) ; idem, 28.IX.2013, PVB (1 ♀ CCo) ; idem, 18.I.2014, PVB (1 ♂ CCo) ; idem, 12.IX.2015,PVP(1 ♂ CCo) ; idem, 12.IX.2015, PVB (1 ♀ CCo) ; idem, 05.XII.2015, PVB (1 ♀ CCo) ; Régina , Station des Nouragues, Camp Inselberg, 27.X.2010, PV (1 ♀ CCo) ; idem, 13.X.2012. PL (1 ♂ CCo) ; Saint-Elie , Réserve Trinité, Crique Aya, 04°35’N, 53°28’W, 10.XI.2013, light trap with GemLight, P.H. Dalens & J. Touroult (1 ♀ CCo) ; Maripasoula , Mont Tabulaire Itoupé, 27.XI.2014, PL (1 ♀ CCo) ; Maripasoula , Massif de Mitaraka, 06.III.2015, Slam (1 ♀ MNHN) ; idem, 25.III.2015, alt. 310 m, PL (1 ♀ MNHN) .

Differential diagnosis: Head black; antennae brown, except antennomeres I-III and VIII-IX, testaceous; pronotum testaceous with a wide median brown patch; elytra entirely dark brown; males: fore femur swollen, with an acute, sharp median ventral tooth; aedeagus with right prolongation of tegmen broadly projected dorsally; left setiferous prolongation elongate, slender; right paramere absent; females: ventrite VII short, wide, posterior margin widely emarginated medially.

Macromalthinus maximiceps differs from M. guyanensis sp. nov., M. orapuensis sp. nov. and M. santaremensis by the absence of right paramere. It differs from M. belemensis by the strong and sharp ventral tooth on fore femur of males. Females of M. maximiceps differ from the other species by the widely emarginated distal margin of ventrite VII.

Additional description: Brancucci (1981a) provided a redescription of M. maximiceps based only on two male specimens. The study of a larger series of specimens enables the observation of colour variations and the first description of females, given below.

Male: Length: 9.5-10.5 mm. Colouration: Colour pattern of body rather constant,except the extension of the brown median patch on the pronotum.Shape of aedeagus constant.

Females ( Figs. 55-58 ): (new description). Length: 8.1-10.3 mm. Head black. Pronotum with large brown patch surrounded by yellow borders, wider laterally and posteriorly. Elytra reddish brown, with thin apical yellow line, sometimes missing. Legs yellow, apical black marks on femora; meso- and metatarsi brown. Abdominal tergites reddish brown; ventrites yellow, except last one, black. Head 1.25 times wider than pronotum. Frons feebly depressed between eyes. Eyes large but not bulging. Pronotum as long as wide, wider medially, lateral edges slightly constricted behind anterior angles. Elytra 1.4 times longer than wide together at base, contiguous on anterior third; narrowing, concave, divergent posteriorly; apex narrow, swollen, lustrous; elytral surface thinly punctate, covered with short, thin yellowish setae, obliquely bent backwards. Ventrite VII ( Fig. 55 ) short, wider apically, lateral margins straight, posterior margin widely emarginated medially. Tergite VIII ( Fig. 56 ) wider apically, posterior margin roundly emarginated; tergite IX ( Fig. 56 ) small, subtriangular, elongate, apex tapering, incised medially; Stylus of coxites ( Fig. 57 ) slightly constricted at base and apex. Measurements of medium size female: TL: 9.6; AL: 6.9; HW: 1.4; IOW: 0.82; IAW: 0.24; OL: 0.64; PL: 1.12; PW: 1.12; EL: 2.14; EW: 1.54.

Remarks: Females differ from males by having narrow- er head, smaller eyes and frons less depressed between the eyes; antennomeres I-IV narrower,IV-VII slightly compressed; fore femora simple, not toothed; fore tibiae not arched.

Distribution: French Guiana ( Figs. 66, 68 ).

Figures

Figures 49-54: Type specimens of Macromalthinus species. (49) M. belemensis Brancucci,1981 (holotype, MPEG).(50) M. brasiliensis (Pic,1906) (= Maronius brasiliensis Pic,1906 (lectotype,MNHN).(51) M. globuliventris Brancucci,1981 (paratype,NHMB).(52) M. maximiceps Pic,1919 (lectotype,MNHN).(53) M.santaremensis Brancucci,1981 (holotype,NHMB).(54) M.schmidli Constantin,2010 (holotype,NHMB).Scale bars:2.0 mm.

Figures 55-58: Macromalthinus maximiceps, female. (55) Ventrite VII. (56) Apex of abdomen, ventral view. (57) Coxite. (58) Left wing. Scale bars: 55-56:0.5 mm;57:0.2 mm; 58: 2.0mm.

Figures 66-69: Distribution of Macromalthinus species. (66) Distribution of Macromalthinus species in South America. (67) Distribution of M. brasiliensis in Brazil.(68)Distribution ofM.maximiceps inFrench Guiana.(69)Distribution of M.guyanensis sp.nov.,andM.orapuensis sp.nov.inFrench Guiana.Background maps of Figs.66-67 by NaturalEarth (available at:www.naturalearthdata.com), and Figs.68-69 byEric Gaba.