Mecocephala bonariensis Schwertner, Grazia and Fernandes, 2002

de Barros, Lurdiana Dayse, Barão, Kim Ribeiro & Grazia, Jocelia, 2022, Taxonomic updates on the Mecocephala group (Hemiptera: Pentatomidae): redescription of Mecocephala Dallas and Paramecocephala Benvegnú, Journal of Natural History (J. Nat. Hist.) 55 (43 - 44), pp. 2691-2747 : 2705-2709

Mecocephala bonariensis Schwertner, Grazia and Fernandes, 2002

( Figures 1b , 2b , 3e–g , 5a–h , 9d–f , 10b, e , 29 ; Table 1)

Mecocephala acuminata Berg 1884: 25 (partim); Pirán 1948: 12; 1959: 41, 42, 1970: 124, 126; Ruffinelli and Pirán 1959: 16; Benvegnú 1968: 91–94, figs 5–6, 10, 14–15, 20–21 (non Dallas 1851).

Mecocephala bonariensis Schwertner et al. 2002: 178–179 , figs 3, 8, 13, 18, 25–27, 32, 36; Grazia and Schwertner 2008: 234; Ruschel et al. 2013: 553; Coscarón 2017: 227; Barão et al. 2017: table 1; Barros et al. 2020b: tables 1, 2.

Type material examined. BRAZIL: PARANÁ: Holotype, m*, Ponta Grossa, Olaria , September 1942 // Holotype/ Mecocephala bonariensis Schwertner, Grazia and Fernandes, 2002 ( DZUP) . Paratypes: BRAZIL: MINAS GERAIS: f*, Alto Itatiaia , 2.200 m, 10 November1955, J. F. Zikan leg. ( FIOC) ; RIO DE]ANEIRO: m* f*, Itatiaia , June 1902, C. Moreira leg. (FIOC, MCNZ –2797–2799) ; PARANÁ: f*, Curitiba , 27 December 1937, C. Westerman leg. ( FIOC) . ARGENTINA: BUENOS AIRES: m*, [Buenos Aires], Capital, 10 Octuber 1949, M. Fritz leg. ( MACN) ; m* f*, Buenos Aires, Belgrano , 28 March 1917 ( UFRG) ; m*, Buenos Aires, Tigre ( UFRG) ; m*, Buenos Aires, 14 Octuber 1896, S. Venturini leg. ( MACN –5659) ; m*, Buenos Aires , 09 Octuber 1896, S Venturini leg. ( MACN –5653) ; f*, Buenos Aires , 20 January 1899, S. Venturini leg. ( MACN) ; f*, Buenos Aires , 22 January 1899, S. Venturini leg. ( MACN) ; f*, Buenos Aires, 23 January 1899, S. Venturini leg. ( MACN) ; f*, Buenos Aires, 24 June 1899, S. Venturini leg. ( MACN) ; f*, Buenos Aires, 04 November 1899, S. Venturini leg. ( MACN) . URUGUAY: MONTEVIDEO: (gender not defined), Montevideo, Pajas Blancas , 21 Octuber 1956 ( UFRG) ; f*, Santiago Vasques, 21 Octuber 1960, [em Caraguata] ( UYIC) .

Table 1. Morphometric parameter measurements of Mecocephala species, in millimetres.

Measurements

Labium Species L1 L2 L3 L4 LP PW LS SW BL BW Mecocephala magna 2.24 ± 0.12 4.96 ± 0.40 5.26 ± 0.35 6.04 ± 0.23 3.74 ± 0.25 8.31 ± 0.38 6.25 ± 0.44 5.25 ± 0.32 19.86 ± 1.46 9.16 ± 0.52 (2.10–2.50) (4.20–5.50) (4.75–5.85) (5.75–6.50) (3.40–4.00) (7.60–8.88) (5.60–6.89) (4.90–5.81) (17.50–21.25) (8.50–9.75) 9 9 8 8 9 9 9 9 9 8 Mecocephala maldonadensis 1.29 2.75 2.38 2.64 2.07 5.28 3.55 3.01 10.55 5.19 2 2 2 2 2 2 2 2 2 2 Mecocephala zikani 1.65 3.45 3.30 3.91 4.72 5.84 4.72 3.84 15.20 6.61 1 1 1 1 1 1 1 1 1 1 Mecocephala maldonadensis 3.13 2.40 2.12 2.14 1.44 0.58 0.37 1.03 0.78 1.16 2 2 2 2 2 2 2 2 2 2 Mecocephala zikani 4.00 2.48 2.88 2.19 - 0.56 0.32 1.12 - - 1 1 1 1 1 1 1

Abbreviations: A1 – length of antennomere 1; A2 – length of antennomere 2; A3 – length of antennomere 3; A4 – length of antennomere 4; A5 – length of antennomere 5; BL – body length; BW – body width; CL – length of clypeus;HL – head length; HLE – length of head at compound eye level; HW – head width; IOD – interocular distance; L1 – length of labiomere 1; L2 – length of labiomere 2; L3 – length of labiomere 3; L4 – length of labiomere 4; PL – pronotum length; PW – pronotum width; SL – scutellum length; SW – scutellum width.

Diagnosis. Body colour dark brown to reddish-dark brown. Antennomere 3 convex dorsally. Antennomere 4 dorsally not grooved. Bucculae sinuous. Proportions of labiomeres 1 <2 <3 <4. Outline of anterolateral margins of pronotum red, crenulate, not punctate. Median furrow of each peritreme of ESES short, reaching less than half of peritreme. Outer margins of metapleural evaporatorium concave. Metathoracic spiracles narrow ( Figure 3e–g ). Spiracles of abdominal sternite 2 not covered by metathorax.

Male genitalia. Pygophore sub-quadrangular ( Figure 5d–g ). Posterolateral angles rounded ( Figure 5d ). Superior processes of dorsal rim of pygophore present ( Figure 5e ). Superior layer of ventral rim with a pair of processes ( Figure 5e ). Inferior layer of ventral rim without processes ( Figure 5e–f ). Phallus ( Figure 9d–f ): Phallotheca shorter than wide apically; dorsal processes of phallotheca uniformly wide. Conjunctiva with a pair of processes, each acute apically, and three pairs of lobes: lateral, median, sclerotised apically, and ventral lobes, entirely membranous. Ductus seminis distalis long relative to conjunctiva.

Female genitalia. Valvifers 8 subequal to laterotergites 9 in length; posterior margins straight. Posterior margins of laterotergites 8 obtusely projected. Laterotergites 9 triangular, obtusely projected apically. Valvifers 9 swollen, anterior margins concave, posterior margins convex ( Figure 5h ). Proximal ductus receptaculi one and a half times longer than the length of vesicular area, lesser diameter, and aspect laminate. Median wall of vesicular area cylindrical subproximally. Distal ductus receptaculi twisted, shorter than vesicular area, same diameter as the diameter of the median wall of vesicular area, and lamellar aspect. Annular flanges convergent relative to each other ( Figure 10b, e ).

Measurements. See Table 1.

Remarks. Mecocephala bonariensis differs from its congeners by antennomere 4 not grooved dorsally, hemelytra surpassing apex of body, inferior layer of ventral rim of pygophore without processes, dorsal processes of phallotheca basally uniformly wider, conjunctiva with three pairs of lobes, median lobe sclerotised apically, ductus seminis distalis long, valvifers 9 swollen, with posterior margin convex, proximal ductus receptaculi convoluted, long, one and a half times longer than vesicular area; lesser diameter, and aspect laminate, median wall of vesicular area cylindrical subproximally, distal ductus receptaculi twisted, shorter than vesicular area and annular flanges convergent.

Distribution. Brazil (Minas Gerais, and Paraná), Argentina (Buenos Aires, Belgrano, and Tigre) and Uruguay (Montevideo) ( Figure 29 ).

Figures

Figure 1. Head and pronotum of Mecocephala in dorsal view. (a) Mecocephala acuminata; (b) Mecocephala bonariensis; (c) Mecocephala curculionoides; (d) Mecocephala magna; (e) Mecocephala maldonadensis; (f) Mecocephala zikani. Scale bars = 0.5 mm.

Figure 2. Head and prothorax of Mecocephala in lateral view. (a) Mecocephala acuminata; (b) Mecocephala bonariensis; (c) Mecocephala magna; (d) Mecocephala maldonadensis; (e) Mecocephala zikani. Scale bars = 0.5 mm.

Figure 3. Thoracic external scent efferent system (ESES) of metasternal glands of Mecocephala. (a–d) Mecocephala acuminata; (e–g) Mecocephala bonariensis; (h) Mecocephala magna. (a–h) mesopleuron and metapleuron in ventral view; (b–g) scanning electron microscopy images of characters of ESES of metasternal glands. Abbreviations: cx2 – mesocoxe; cx3 – metacoxae; ev – evaporatorium; ms – mesopleuron; mt – metapleuron; mts – metathoracic spiracle; o – ostiole; om – outer margin; pod – periostiolar depression. Scale bars: a, h = 0.5 mm; b, e = 500 µm; c–d, f–g = 200 µm.

Figure 5. Mecocephala bonariensis Schwertner, Grazia and Fernandes, 2002. (a–c) Habitus of holotype in dorsal, ventral and lateral view; (d–g) pygophore in dorsal, posterior, ventral and lateral view; (h) genital plates in posteroventral view. Abbreviations: alvr – area between layers of ventra riml; dr – dorsal rim; ilvr – inferior layer of ventral rim of pygophore; pilvr – process of inferior layer of ventral rim; pslvr – process of superior layer of ventral rim; slvr – superior layer of ventral rim of pygophore; vr – ventral rim. Scale bars: a–c = 2.0 mm; d–h = 1.0 mm. (Parameres and segment X not shown).

Figure 9. Phallus of Mecocephala species in dorsal (left column), lateral (center column) and ventral (right column) views. (a–c) Mecocephala acuminata; (d–f) Mecocephala bonariensis; (g–i) Mecocephala magna. Abbreviations: aa – articulatory apparatus; cj – conjunctiva; dc – dorsal connective; dpph – dorsal process of phallotheca; mlcj – median lobe of conjunctiva; pcj – process of conjunctiva; pdpph – posterodorsal projection of phallotheca; ph – phallotheca; plpph – posterolateral projection of phallotheca; pve – process of vesica; vbpph – ventrobasal projection of phallotheca; vlcj – ventral lobe of conjunctiva. Scale bars = 1.0 mm.

Figure 10. Female receptaculum seminis and aussenwand of Mecocephala species. (a, d) Mecocephala acuminata; (b, e) Mecocephala bonariensis; (c, f) Mecocephala magna. Abbreviations: aaf – anterior annular flanges; cs – capsula seminalis; ddr – distal ductus receptaculi; paf – posterior annular flange; pdr – proximal ductus receptaculi; pi – pars intermedialis; rs – ring sclerites; tvi – thickening of vaginal intima; va – vesicular area. Scale bars = 1.0 mm.

Figure 29. Map showing the geographical distribution of Mecocephala and Paramecocephala species. Yellow star = new record of P. subsolana.