Paramecocephala Benvegnú, 1968

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 : 2725-2731

Paramecocephala Benvegnú, 1968

Paramecocephala Benvegnú, 1968: 87–96 ; Frey-da-Silva et al. 2002a: 209–225; Frey-da-Silva et al. 2002b: 181; Grazia and Schwertner 2008: 234; Ruschel et al. 2013: 554–555; Coscarón 2017: 230–231; Barão et al. 2017: 110; Barros et al. 2020b: 321, 323, 335, 351, 353, 355.

Type species. Paramecocephala foveata Benvegnú, 1968 , by monotypy.

Diagnosis. Head rounded apically; apical portion of mandibular plates sinuous; clypeal suture inserted posteriorly to an imaginary line crossing anterior margin of compound eyes; anteocular processes absent; antenniferous tubercles visible in dorsal view; antennomere 3 slightly flattened dorsally; labiomeres 3 and 4 entire; posterior margin of pronotum slightly convex; each ostiole of the thoracic ESES guttiform; marginal processes of dorsal rim of pygophore present; middle region of dorsal rim of pygophore entire or notched; area between layers of ventral rim depressed in caudal view; lateral margins of superior layer of ventral rim entire. Valvifers 8 strongly convex.

Redescription. Body oval. Dorsal and ventral surface slightly convex. Head longer than wide, except in P. bachmanni , and rounded apically ( Figure 11 ). Mandibular plates shorter than clypeus, obtuse apically; outer lateral margins of mandibular plates sinuous, lower in relation to inner margins, level in P. fusca . Clypeal apex obtuse, at a higher level than mandibular plates longitudinally and in lateral view; clypeal suture inserted posteriorly to an imaginary line crossing anterior margin of compound eyes.

Anteocular processes absent. Antenniferous tubercles visible in dorsal view, each with an obtuse lateral process. Proportions of antennomeres: 1> 2 <3> 4 <5. Antennomere 1 not reaching apex of head; antennomere 2 apparent ( Figure 11 ); antennomere 3 slightly flattened; antennomere 4 slightly flattened dorsally. Bucculae sinuous, tapering towards base of head, not reaching the base of head ( Figure 12 ).

Length of labium variable between species. Proportions of labiomeres: 1 <2> 3> 4; first labiomere contained between bucculae, labiomere 2 flattened laterally and smaller than 3 and 4 combined; labiomeres 3 and 4 entire. Pronotum trapezoidal ( Figure 11 ), sloping at the height of the humeral angles and towards the head or not; each anterior angle of pronotum with an obtuse process, directed laterally, varying in length; anterolateral margins of pronotum showing interespecific varibility, explanate and not reflexed; humeral angles not produced; posterolateral margins of pronotum sinuous; posterior margin of pronotum slightly convex ( Figure 11 ). Mesosternal carina shallow. Metasternum grooved, shallow. Each ostiole of the thoracic ESES guttiform, opening posterolaterally; periostiolar depressions present; each ostiolar peritreme spout-like. Evaporatorium punctate, reaching more than half of the width of metapleuron. Anterolateral margins of evaporatorium on metapleuron rounded. Evaporatorium on mesopleuron surpassing the limits of mesocoxal sutures, reaching the anterior angles and in a diagonal from mesepimeron to mesepisternum ( Figure 13 ).

Gyrification of evaporatorium with high wrinkles, low in P. foveata and P. uruguayensis . Metathoracic spiracles wide. Femora unarmed, femora longer than tibiae. Tibiae grooved dorsally. Tarsi 3-segmented. Scutellum longer than wide, apex rounded, surpassing the posterior margin of the abdominal tergite 5. Basal angles of scutellum foveate, foveae size variable. Corium longer than scutellum, surpassing apices of abdominal tergite 5; apex of each radial vein calloused; membrane with linear veins, varying in number. Membranal suture sinuous. Apex of hemelytra surpassing or not apex of body. Connexivum well exposed or not, concolourous with dorsal surface. Abdominal sternites with medial longitudinal groove reaching sternite 7. Posterolateral angles of sternites obtusely produced. Callus mesial to each spiracle. Spiracles circular, colour variable, spiracles of abdominal sternite 2 covered by metathorax. Trichobothria lateral to an imaginary longitudinal line tangent to the spiracles or separated by that line. Genital cup of pygophore narrow, broad in P. foveata and P. uruguayensis , opened dorsoposteriorly. Lateral margin of dorsal rim with marginal processes; middle region of dorsal rim entire or notched, and extension of dorsal rim well developed or obsolete. Layers of ventral rim not separated by a carina; area between layers excavated or depressed and striated in caudal view. Superior layer of ventral rim projected over genital cup, developed laterally to segment X, covering or not parameres; lateral margins entire in superior view; superior processes present, absent in P. fusca and P. guianensis . Inferior layer of ventral rim with or without processes. Segment X ogival (rectangular, with arcuate apex), not carinate, with tumescent processes basally. Parameres present, crown reduced. Dorsal connectives of articulatory apparatus variable in relation to middle of phallotheca. Processus capitati longer, reaching phallotheca distal margin. Phallotheca piriform, short, and with three pairs of projections: posterodorsal, posterolateral and ventrobasal; dorsal processes of phallotheca wider, apically curved and longer than the posterodorsal projections of phallotheca; conjunctiva with one or two pairs of processes, and three pairs of lobes ( Figures 26 , 27 ), two pairs in P. foveata . Process of vesica long. Ductus seminis distalis extremely long, in relation to conjunctiva, convolute. Valvifers 8 convex, sub-equal to laterotergites 9, smaller in P. guianensis , partially covering the valvifers 9; mesial margins not emarginate and juxtaposed. Valvulae 8 not visible externally. Laterotergites 8 lacking spiracles; posterior margins showing interespecific varibility. Valvifers 9 flat, levelled to segment X in lateral view, with sclerotised lateral arms attaining anterior margins of laterotergite 9, anterior and posterior margins varying within species. Laterotergites 9 spatulate, surpassing or not the abdominal tergite 8, mesial margins divergent, posterior margins obtusely projected. Valvulae 9 with 1 + 1 medially sclerotised areas. Ring sclerites elliptical. Arcuate posterior portion of thickening of vaginal intima longer than the round anterior portion. Proximal and distal ductus receptaculi long, at least three times longer than vesicular area, and convolute. Ductus within the vesicular area straight and median wall enlarged subproximally. Anterior annular flange shorter in relation to pars intermedialis, larger in P. foveata . Posterior annular flange wider in relation to capsula seminalis , thinner in P. fusca . Pars intermedialis rectilinear. Capsula seminalis globose, with length variable in relation to pars intermedialis ( Figure 28 ).

Distribution. Venezuela (Aragua), French Guiana (Montsinéry), Suriname, Guiana (Rupununi), Brazil (Amazonas, Bahia, Espírito Santo, Mato Grosso, Minas Gerais, Paraná, Santa Catarina, São Paulo, and Rio Grande do Sul), Ecuador (Napo, and Coca), Argentina (Buenos Aires, and Corrientes) and Uruguay (Artigas, and Montevideo) ( Figure 29 ).

Key to Paramecocephala species (adapted from Frey-da-Silva et al. 2002a)

1. Head wider than long; labium not reaching the posterior portion of abdominal sternite 4 ( Figure 15b ). Posterior margins of valvifers 8 arched ( Figure 15g )................... ............................................................................................................................................... P. bachmanni – Head longer than wide; labium surpassing the posterior portion of abdominal sternite 4. Posterior margins of valvifers 8 not forming a semicircle................................................. 2

2 Labium not surpassing the posterior portion of abdominal sternite 5 ............................3 – Labium surpassing the posterior portion of abdominal sternite 5..................................... 6

3 Segment X of male concave, with basal carina in ‘u̍; inferior layer of ventral rim of pygophore with 1 + 1 projections very close together ( Figure 21g ). Posterior margins of laterotergites 8 acutely projected, surpassing the laterotergites 9 ( Figure 21h )........ ................................................................................................................................................. P. guianensis – Segment X of male with subtriangular median carina; inferior layer of ventral rim of the pygophore without or with projections, in this case spaced at a distance equal to the width of the X segment. Posterior margins of laterotergites 8 rounded, not surpassing the laterotergites 9.......................................................................................................... 4

4 Inferior layer of ventral rim of pygophore without projections ( Figure 14f ). Posterior margins of valvifers 8 sinuous, slightly concave in the middle third ( Figure 14g ).......... ..................................................................................................................................................... P. australis – Inferior layer of ventral rim of pygophore with projections. Posterior margins of valvifers 8 sinuous or sub-rectilinear............................................................................................... 5

5 Projections of superior layer of ventral rim short, not reaching the processes of segment X, not covering the parameres ( Figure 20d ). Posterior margins of laterotergites 8 obtusely projected, slightly surpassing the laterotergites 9, these with posterior margins rounded ( Figure 20g )........................................................................................ P. fusca – Projections of superior layer of ventral rim long, reaching the processes of segment X, partially covering the parameres ( Figure 23d ). Posterior margins of laterotergites 8 straight, not surpassing the laterotergites 9, these with posterior margins straight ( Figure 23g )......................................................... ......................................................... P. uruguayensis

6 Labium reaching the middle of the abdominal sternite 7 ( Figure 19c ). Diameter of the fovea in each basal angle of the scutellum larger than the diameter of a compound eye ( Figures 18a , 19a )..................................................... ..................................................... P. foveata – Labium reaching the middle of abdominal sternite 6. Diameter of the fovea in each basal angle of the scutellum smaller than the diameter of a compound eye............... 7

7 Body size larger than 14.00 mm; body reddish brown to black; legs red to black; sub-lateral margins of abdomen red or ferruginous, with punctures dark brown ( Figures 16c , 17c ). Posterior margins of valvifers 9 straight ( Figure 16g ) .................................................................................................................................... P. bergrothi . – Body size smaller than 14.00 mm; body yellowish brown to dark brown; legs brown; sub-lateral margins of abdomen light brown, with concolourous punctures. Posterior margins of valvifers 9 convex ............................................................................................................ 8

8 Anterolateral margins of pronotum gently crenulate and straight ( Figures 11g , 22a ). Connexivum well exposed ( Figure 22a ).................................................................. P. subsolana – Anterolateral margins of pronotum smooth and concave ( Figures 11i , 24a ). Connexivum poorly exposed ( Figure 24a ).................. Paramecocephala helenae sp. nov.

Figures

Figure 11. Head and pronotum of Paramecocephala in dorsal view. (a) Paramecocephala australis; (b) Paramecocephala bachmanni; (c) Paramecocephala bergrothi; (d) Paramecocephala foveata; (e) Paramecocephala fusca; (f) Paramecocephala guianensis; (g) Paramecocephala subsolana; (h) Paramecocephala uruguayensis; (i) Paramecocephala helenae sp. nov. Scale bars = 0.5 mm.

Figure 12. Head and prothorax of Paramecocephala in lateral view. (a) Paramecocephala australis; (b) Paramecocephala bachmanni; (c) Paramecocephala bergrothi; (d) Paramecocephala foveata; (e) Paramecocephala fusca; (f) Paramecocephala guianensis; (g) Paramecocephala subsolana; (h) Paramecocephala uruguayensis; (i) Paramecocephala helenae sp. nov. Scale bars = 0.5 mm.

Figure 13. Thoracic external scent efferent system (ESES) of metasternal glands of Paramecocephala. (a–d) Paramecocephala australis; (e) Paramecocephala bachmanni; (f) Paramecocephala bergrothi; (g) Paramecocephala foveata; (h–j) Paramecocephala fusca; (k) Paramecocephala guianensis; (l) Paramecocephala subsolana; (m) Paramecocephala uruguayensis; (n) Paramecocephala helenae sp. nov. (a, e–g, k–n) meso- and metapleural in ventral view; (b–d, h–j) scanning electron microscopy images of characters of ESES of metasternal glands. Abbreviations: cx2 – mesocoxae; cx3 – metacoxae; ev – evaporatorium; ms – mesopleuron; mt – metapleuron; mts – metathoracic spiracle; o – ostiole; om – outer margin; pod – periostiolar depression. Scale bars: a, e–g, k–n = 0.5 mm; b, h = 500 µm; c–d, i–j = 200 µm.

Figure 14. Paramecocephala australis Frey-da-Silva and Grazia, 2002. (a–c) Habitus of holotype in dorsal, ventral and lateral view; (d–f) pygophore in dorsal, posterior and ventral view; (g–h) genital plates in posteroventral and lateral view. Abbreviations: alvr – area between layers of ventral rim; ilvr – inferior layer of ventral rim of pygophore; mpdr – marginal process of dorsal rim of pygophore; slvr – superior layer of ventral rim of pygophore. Scale bars: a–c = 2.0 mm; d–f = 1.0 mm; g–h = 0.5 mm. (Parameres and segment X not shown).

Figure 15. Paramecocephala bachmanni Frey-da-Silva and Grazia, 2002. (a–c) Habitus of holotype in dorsal, ventral and lateral view; (d–e) pygophore in dorsal view; (f) pygophore in superior view; (g) pygophore in ventral view; (h–i) genital plates in posteroventral and lateral view. Abbreviations: alvr – area between layers of ventral rim; edr – extension of dorsal rim of pygophore; ilvr – inferior layer of ventral rim of pygophore; mpdr – marginal process of dorsal rim; par – paramere; pslvr – process of superior layer of ventral rim; slvr – superior layer of ventral rim of pygophore; x – segment X. Scale bars: a–c = 2.0 mm; d,f–g = 1.0 mm; h–i = 0.5 mm.

Figure 16. Paramecocephala bergrothi Frey-da-Silva and Grazia, 2002. (a–c) Habitus of holotype in dorsal, ventral and lateral view; (d–f) pygophore of reddish variation in dorsal, posterior and ventral view; (g–h) genital plates in posteroventral and lateral view. Abbreviations: edr – extension of dorsal rim of pygophore; ilvr – inferior layer of ventral rim of pygophore; mpdr – marginal process of dorsal rim of pygophore; slvr – superior layer of ventral rim of pygophore. Scale bars: a–c = 2.0 mm; d–f = 1.0 mm; g–h = 0.5 mm. (Parameres and segment X not shown).

Figure 17. Paramecocephala bergrothi Frey-da-Silva and Grazia, 2002, melanic variation. (a–c) Habitus in dorsal, ventral and lateral view; (d–e) pygophore in dorsal view; (f) pygophore in superior view. Abbreviations: edr – extension of dorsal rim of pygophore; par – paramere; slvr – superior layer of ventral rim of pygophore; x – segment X. Scale bars: a–c = 2.0 mm; d, f = 1.0 mm. (Parameres and segment X not shown).

Figure 18. Paramecocephala foveata Benvegnú, 1968. Holotype. (a–c) Habitus in dorsal, ventral and lateral view; (d) abdomen in ventral view; (e) prepared plate of the holotype; (f) detail of segment X; (g) phallus in dorsal view; (h) detail of vesica. Abbreviations: dpph – dorsal process of phallotheca; pcj – process of conjunctiva; pdpph – posterodorsal projection of phallotheca; plpph – posterolateral projection of phallotheca. Scale bars: a–d = 2.0 mm.

Figure 19. Paramecocephala foveata Benvegnú, 1968. (a–c) Habitus in dorsal, ventral and lateral view; (d–e) genital plates in posteroventral and lateral view. Scale bars: a–c = 2.0 mm; d–e = 0.5 mm.

Figure 20. Paramecocephala fusca (Haglund, 1968). (a–c) Habitus in dorsal, ventral and lateral view; (d–f) pygophore in dorsal, posterior and ventral view; (g–h) genital plates in posteroventral and lateral view. Abbreviations: alvr – area between layers of ventral rim; ilvr – inferior layer of ventral rim of pygophore; par – paramere; pilvr – process of inferior layer of ventral rim; slvr – superior layer of ventral rim of pygophore. Scale bars: a–c = 2.0 mm; d–f = 1.0 mm; g–h = 0.5 mm.

Figure 21. Paramecocephala guianensis Frey-da-Silva and Grazia, 2002. (a–c) Habitus of holotype in dorsal, ventral and lateral view; (d–e) pygophore in dorsal view; (f–g) pygophore in posterior and ventral view; (h) genital plates, reinterpretation of the illustration by Schwertner et al. 2002. Abbreviations: alvr – area between layers of ventral rim; ilvr – inferior layer of ventral rim of pygophore; la8 – laterotergites 8; la9 – laterotergites 9; pilvr – process of inferior layer of ventral rim; slvr – superior layer of ventral rim of pygophore; vf8 – valvifers 8; vf9 – valvifers 9; x – segment X. Scale bars: a–c = 2.0 mm; d, f–g = 1.0 mm; h = 0.5 mm.

Figure 22. Paramecocephala subsolana Frey-da-Silva and Grazia, 2002. (a–c) Habitus of holotype in dorsal, ventral and lateral view; (d–f) pygophore in dorsal, posterior and ventral view; (g–h) genital plates in posteroventral and lateral view. Abbreviations: alvr – area between layers of ventral rim; ilvr – inferior layer of ventral rim of pygophore; mpdr – marginal process of dorsal rim of pygophore; slvr – superior layer of ventral rim of pygophore. Scale bars: a–c = 2.0 mm; d–f = 1.0 mm; g–h = 0.5 mm. (Parameres and segment X not shown).

Figure 23. Paramecocephala uruguayensis (Pirán, 1970). (a–c) Habitus in dorsal, ventral and lateral view; (d–f) pygophore in dorsal, posterior and ventral view; (g–h) genital plates in posteroventral and lateral view.Abbreviations: alvr – area between layers of ventral rim; ilvr – inferior layer of ventral rim of pygophore; mpdr – marginal process of dorsal rim of pygophore; slvr – superior layer of ventral rim of pygophore. Scale bars: a–c = 2.0 mm; d–f = 1.0 mm; g–h = 0.5 mm.

Figure 24. Paramecocephala helenae sp. nov. Holotype. (a–c) Habitus in dorsal, ventral and lateral view; (d–f) pygophore in dorsal, posterior and ventral view; (g–h) genital plates in posteroventral and lateral view. Scale bars: a–c = 2.0 mm; d–e = 0.5 mm.

Figure 26. Phallus of Paramecocephala species in dorsal (left column), lateral (center column)) and ventral (right column) view. Conjunctiva with a pair of processes. (a–c) Paramecocephala australis; (d– f) Paramecocephala subsolana. Abbreviations: 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 27. Phallus of Paramecocephala species in dorsal (left column), lateral (center column) and ventral (right column) view. Conjunctiva with two pairs of processes. (a–f) Paramecocephala bergrothi: (a–c) reddish variation; (d–f) melanic variation; (g–i) Paramecocephala fusca; (j–l) Paramecocephala uruguayensis. Abbreviations: aa – articulatory apparatus; cj – conjunctiva; dc – dorsal connective; dpph – dorsal process of phallotheca; dsd – ductus seminis distalis; 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 28. Female receptaculum seminis and aussenwand of Paramecocephala species. (a) Paramecocephala australis; (b) Paramecocephala bergrothi; (c) Paramecocephala foveata; (d) Paramecocephala fusca; (e) Paramecocephala subsolana; (f) Paramecocephala uruguayensis. 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.