Macromalthinus piceiventris, 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: 11-13

publication ID 10.11606/1807-0205/2018.58.58

persistent identifier

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scientific name

Macromalthinus piceiventris

sp. nov.

Macromalthinus piceiventris   sp. nov.

( Figs. 4 View Figures 1-6 , 10 View Figures 7-12 , 16 View Figures 13-18 , 22 View Figures 19-24 , 28 View Figures 25-30 , 34 View Figures 31-36 , 40 View Figures 37-42 , 46 View Figures 43-48 )

Type material: HOLOTYPE: ♂ BRAZIL. Amazonas : Presidente Figueiredo, AM 240, km 24, 02°35’21”S, 60°06’55”W, 11-12.XII.2004, armadilha de luz mista, F.F. Xavier F. & G.M. Lourido ( INPA) ( Fig. 4 View Figures 1-6 ) GoogleMaps   . PARATYPES (3 ♀). BRAZIL. Amazonas : Manaus, Reserva Ducke, II.1995, armadilha malaise, MGV Barbosa col. (1 ♀ INPA, 1 ♀ MZSP 35638 View Materials )   ; idem, Reserva Ducke , 26 km NE Manaus, X.1995, malaise 1, plot C, Barbosa, M.G.V. (1 ♀ BMNH 2003-84)   .

Differential diagnosis: Head black, antennomeres I-II testaceous, slightly darker dorsally, III to half of VII black, half of VII-XI orangish yellow,gradually darker apicad; antennomeres slightly flattened dorso-ventrally; pronotum orangish yellow,sometimes with medial brownish patches; elytra entirely black; abdominal ventrites and tergites dark brown to black; males: fore femur swollen, without distinct tooth; ventrite VIII with a short transverse lateral ridge near left margin and a long longitudinal ridge along right margin; aedeagus with right prolongation of tegmen broadly projected dorsally; left setiferous prolongation short and stout, with a dense tuft of long and thick apical setae; females: ventrite VII short, distal margin with two acute projections in the middle.

Macromalthinus piceiventris   sp. nov. differs from M. maximiceps   , M. belemensis   , M. santaremensis   and M.luteoapicalis   by the dark-brown to black abdomen, fore femur of males without a distinct ventral tooth, aedeagus with a very short setiferous prolongation, and a much longer ventrite VII of females.

Description: Length: 8.4 mm. Colouration: Head and clypeus black; antennomeres I-II testaceous, slightly darker dorsally, III to half of VII black, half of VII-XI orangish yellow, gradually darker apically; labium and maxillae pale yellow, darker on dorsal face of last labial and maxillary palpomeres; pronotum orangish yellow, sometimes with medial brownish patches; elytra black; wings dark brown; thorax and legs dark brown to black, except coxae and base of femora, orange yellow; abdominal ventrites and tergites dark brown to black ( Fig. 4 View Figures 1-6 ).

Males: Head large, 1.1 times wider than pronotum; temples elongate, strongly tapering posteriorly; frons deeply depressed between eyes. Eyes large, bulging, internal margins convergent anteriorly. Antennae filiform, slightly flattened dorso-ventrally, covered with thick setae, longer on ventral sides of antennomeres I-IV; antennomere I elongate, slightly widened apically, II very short, III 2.4 times longer than II; antennomeres III-VII gradually increasing in length, VIII-XI decreasing in length. Pronotum ( Fig. 10 View Figures 7-12 ) as long as wide; anterior margin arched, lateral margins almost straight, gradually narrowed anteriorly, constricted laterally, near anterior angles; pronotal surface elevated antero-medially and near posterior angles, forming two lateral shallow grooves posteriorly convergent and a shallow medial hollow. Elytra short, rugulose, densely covered with short, thin setae; sutures dehiscent from posterior half; lateral margins narrowed after middle; apex swollen dorsally. Fore femur ( Fig. 16 View Figures 13-18 ) swollen, without distinct tooth; femora, tibiae and tarsomeres increasing in length from fore to hind legs; tarsal claws simple, not toothed. Abdominal tergites and sternites broadly sclerotized; glandular pores slightly prominent; tergite VIII asymmetrical,notched posteriorly; ventrite VI broadly notched, membranous posteriorly; ventrite VII ( Fig. 22 View Figures 19-24 ) H-shaped, sides sinuate, with deep, wide membranous area anteriorly, and deep, wider posterior notch longer than a half of ventrite; ventrite VIII ( Fig. 28 View Figures 25-30 ) asymmetrical, elongate, strongly convex; short transverse lateral ridge near left margin, long longitudinal ridge along right margin. Aedeagus ( Fig.34 View Figures 31-36 ) with right prolongation of tegmen broadly projected dorsally, without apophysis on its dorsal surface; left setiferous prolongation short, stout, with dense tuft of long, thick apical setae; right paramere elongate, slightly wider medially; left paramere elongate, flat, apex rounded, partially covering dorsal surface of median lobe; median lobe straight, with long apical membranous surface dorsally. Measurements of holotype: TL: 8.2; AL: 6.7; OL: 0.77; HW: 1.4; IOW: 0.62; IAW: 0.16; PL: 1.21; PW: 0.12; EL: 2.0; EW: 1.6. Length of each antennomere: aI: 0.56; aII: 0.22; aIII: 0.52; aIV: 0.63; aV: 0.71; aVI: 0.77; aVII: 0.75; aVIII: 0.72; aIX: 0.66; aX: 0.61; aXI: 0.61.

Female: similar to males; differ by eyes smaller and less prominent; inter-antennal space wider, frons feebly depressed between eyes; fore femora slender, without intumescence or tooth; lateral margins of tergite VIII round- ed, glandular openings broadly projected posteriorly; ventrite VI entire, not notched posteriorly; ventrite VII ( Fig. 40 View Figures 37-42 ) elongate, lateral margins arched, posterior margin strongly sinuous, forming two rounded projections in the middle, anterior margin emarginated with weak rounded notch at middle; base of coxites ( Fig. 46 View Figures 43-48 ) elongate, slender, apex wide, rounded laterally, with a projection on distal margin, behind style, bearing few thin setae; styles elongate, strongly wider apically, densely covered with thick setae. Measurements of medium size female paratype: TL: 8.2; AL: 6.8; OL: 0.56; HW:1.25; IOW: 0.63; IAW: 0.22; PL: 0.97; PW: 1.0; EL: 2.0; EW: 1.3. Length of each antennomere: aI: 0.56; aII: 0.22; aIII: 0.52; aIV: 0.63; aV: 0.71; aVI: 0.77; aVII: 0.75; aVIII: 0.72; aIX: 0.66; aX: 0.61; aXI: 0.61.

Etymology: The specific epithet is derivative of the Latin words piceus (black) + ventris (abdomen), referring to the dark-brown to black abdominal sternites of this species.

Distribution: Brazil (Amazonas state) ( Fig. 66 View Figures 66-69 ).

Locality description: One of the localities, Reserva Florestal Ducke, is a well-preserved 100 km ² forest area in central Amazonia, ca. 26 km north-eastern from Manaus. It is currently considered as the most studied site along all the Brazilian Amazon.The main vegetation in the Reserve is terra firme forest, without flooded areas ( Ribeiro et al., 1999).The other locality is the municipality of Presidente Figueiredo, whose vegetation is composed of terra firme, dense ombrophilous forest with igapó forests – flooded areas along rivers and lakes formed during rainy seasons.


Instituto Nacional de Pesquisas da Amazonia