Mecocephala magna 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 : 2709-2713

Mecocephala magna Schwertner, Grazia and Fernandes, 2002

( Figures 1d , 2c , 3h , 6a – 1h , 9g – 1i , 10c , 1f , 29 ; Table 1)

Mecocephala rubripes Buckup 1961: 11 (non Berg, 1894).

Mecocephala magna Schwertner et al. 2002: 181–182 , figs 1, 10, 15, 20, 28–30, 33, 37; Ruschel et al. 2013: 553; Barros et al. 2020b: 351, figs 3C, 18B, 3N, tables 1, 2.

Type material examined. BRAZIL: RIO GRANDE DO SUL: Holotype, m*, Capão do Leão, 28 Octuber 1984, A.T. Barbosa leg. ( MECB) . Paratypes: BRAZIL: RIO GRANDE DO SUL: f*, Viamão ( MCNZ –2800) ; f*f*, São Leopoldo , Pe. Buck leg. ( MCNZ –2801[without abdomen]; 2802) ; f*, Pelotas , September 1995, L. Krüger leg. ( MECB – P 151) ; m*, Pelotas, November 1990, J. Freitas leg. ( MECB) ; m*, Pelotas , March 1986, R. Brancher leg. ( MECB) ; f*, Pelotas , 25 September 1975 . URUGUAY: CERRO LARGO: f*, Santa Clara de Olimar, T[reinta] y T[res] , 19 November 1958, L. C. De Zolessi leg. ( UYIC) .

No data: f* ( UFRG).

Diagnosis. Body dark brown to reddish-dark brown. Anteocular processes present. Antennomere 3 slightly flattened dorsally, and not grooved dorsally. Bucculae sinuous. Apex of the labium visible in dorsal view, in resting position. Proportions of labiomeres 1 <2 <3 <4. Outline of anterolateral margins of pronotum crenulate, punctate and reflected. Median furrow of each peritreme of ESES long, reaching more than half of peritreme; outer margins of metapleural evaporatorium concave. Metathoracic spiracles narrow ( Figure 3h ). Apices of each radial vein with a large, orange to red conspicuous callosity ( Figure 6a ). Spiracles of abdominal sternite 2 not covered by metathorax.

Male genitalia. Pygophore trapezoidal ( Figure 6d ). Posterolateral angles quadrate ( Figure 6d ). Superior layer of ventral rim with a pair of processes ( Figure 6e–f ). Inferior layer of ventral rim with a pair of processes ( Figure 6g ). Phallus ( Figure 9g –i ): Phallotheca shorter than wide apically; dorsal processes narrower apically than the median width and curved. Conjunctiva with a pair of processes, each acute apically, and two pairs of lobes: median and ventral lobes, membranous. Ductus seminis distalis extremely long.

Female genitalia. Valvifers 8 sub-equal to laterotergites 9 in length; posterior margins sinuous. Posterior margins of laterotergites 8 straight. Laterotergites 9 triangular, obtusely projected apically. Valvifers 9 flat, anterior margins convex and posterior margins concave ( Figure 6h ). Proximal ductus receptaculi long, at least three times longer than vesicular area, and equal diameter. Median wall of vesicular area enlarged sub-proximally, and straight. Distal ductus receptaculi convoluted, extremely long, at least three times longer than vesicular area, same diameter as the diameter of the median wall of vesicular area. Annular flanges parallel to each other ( Figure 10c, f ).

Measurements. See Table 1.

Remarks. Mecocephala magna differs from its congeners by apex of labium surpassing body, outline of anterolateral margins of pronotum punctate, outer margin of evaporatorium on metapleuron convex, posterolateral angles of pygophore quadrate, dorsal processes of phallotheca narrower apically than the width medially, posterior margins of laterotergites 8 truncate, distal ductus receptaculi long, at least three times longer than vesicular area.

Distribution. Brazil (Rio Grande do Sul) and Uruguay (Santa Clara de Olimar) ( 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 6. Mecocephala magna Schwertner, Grazia and Fernandes, 2002. (a–c) Habitus of holotype in dorsal, ventral and lateral view; (d) pygophore in dorsal view; (e–f) pygophore in posterior view; (g) pygophore in ventral view; (h) genital plates in posteroventral view. Abbreviations: dr – dorsal rim; ilvr – inferior layer of ventral rim of pygophore; 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.