Mesomphalia nudoplagiata Spaeth 1901

Mesomphalia nudoplagiata Spaeth, 1901

(Figs. 82–90, 148–151, 156, 169)

Mesomphalia nudoplagiata Spaeth, 1901: 339; 1914: 33; Blackwelder, 1946: 738; Borowiec, 1999: 117.

Measurements (11 males / 5 females). Total length: 16.5–17.0/18.0–19.0; greatest elytral width: 15.0–16.5/ 15.5–17.0; pronotum length: 3.5–4.0/3.8–4.6; greatest width of pronotum: 9.0–9.7/9.1–10.3; elytral length/width ratio: 1.0–1.13/1.12–1.16; pronotal length/width ratio: 0.38–0.41/0.41–0.45.

Diagnosis. Mesomphalia nudoplagiata can be easily differentiated by: elytra with setae along basal third except for two glabrous diamond-shaped areas continuing in an irregular band, forming a large, rounded area at apical third and another conspicuous and glabrous triangular area at apex.

Redescription. Body subrounded, with divergent elytral margins until median region and convergent towards apex; yellowish-brown setae. Head with rugged vertex with course, dense punctures and erect, sparse setae. Coronal suture with reddish-brown depression. Frontoclypeus depressed at median region.

Antennae black, except apex of scape and antennomere III reddish-brown, pedicel, yellowish-brown or reddish-brown. Antennomeres III–IV increasing in length, about 2.5x longer than pedicel; V subequal in length to III; VI–VIII subequal in length, slightly shorter than V; IX–X subequal in length to V; XI with rounded apex.

Prothorax with a pair of subtriangular spots of long and semidecumbent setae, glabrous centrally. Pronotum with anterior margin slightly sinuous; posterior angle truncate. Prosternum with longitudinal sulcus; apex of prosternal process with long, dense and semidecumbent setae. Prosternal collar convex and slightly projected forward, with anterior margin somewhat truncate, followed by deep, long and narrow transverse groove. Prosternal process with long, dense and semidecumbent setae at longitudinal sulcus, which starts at median region and extends to apex; apical margin rounded.

Mesoventrite glabrous; mesepimera glabrous or with long, sparse and decumbent setae; mesepisterna with long, sparse and decumbent setae; mesoventrite process with semidecumbent setae; mesoventrite process with lateral margins wide and truncated apex, about 2x shorter than prosternal process, U-shaped, with truncated apex. Elytra about 3.5x longer than pronotum, with shiny reticulation and fine punctures above humeral angles, continuing beyond elytral disc until median region and rounded opaque areas; setae along basal third except for humeral angle, two glabrous diamond-shaped areas continuing in an irregular band, forming a large, rounded area at apical third and another conspicuous triangular area at apex. Lateral margin more expanded at median region; apical angle acute, convergent and directed dorsally. Gibbosity 0.46–0.5x elytral length, with perpendicular apex to disc.

Metaventrite glabrous, except metepimera with long, dense and decumbent setae; posterior margin with a row of short, dense and erect setae.

Abdominal ventrites III–IV with ellipsoidal reddish-brown spots, laterally. Ventrites I–IV with band of long, dense and decumbent setae on lateral extremities and shorter, dense setae on median region.

Male terminalia (Figs. 82–85). Tergite VIII convex, sclerotized, with rounded apical margin and basal margin with lateral apodemes, long and dense setae. Tegmen (Figs. 84–85) bifurcate, distinct manubrium and basal region of aedeagus, which is flat dorso-ventrally; same width throughout its length, partially sclerotized, with four membranous regions. Median lobe (Figs. 82–83) sclerotized, elongated, curved laterally, with apical extremity narrow and truncate; internal sac membranous, ostium with two semi-sclerotized plates.

Female terminalia (Figs. 86–90). Tergite VIII similar to that observed in male. Sternite VIII (Fig. 89) sclerotized, with long setae at apical margin, becoming denser laterally; lateral arms fused to sternite IX, forming transverse membranous sacs; apodemes with parallel margins, about 1.5x the length of apical region. Sternite IX (Figs. 86, 88) subdivided into two plates with long and erect setae at apical margin; a small, sclerotized, dropshaped area at median region, next to base. Tergite X (Figs. 87–88) with two regions sclerotized next to apical margin. Spermatheca (Fig. 81) strongly sclerotized, with base slightly wider than apex; apex obtuse; vasculum hook-shaped; ampulla present, about half the length of vasculum, abruptly enlarged medially. Spermatheca duct long, anterior third not coiled, posterior ⅔ coiled, around 3x the length of vasculum. Spermathecal gland short and narrow, laterally attached to ampulla.

Remarks. Mesomphalia nudoplagiata (Figs. 86–90) is similar to M. sublaevis (Figs. 59–63) in the spermatheca and sternites VIII and IX. Mesomphalia nudoplagiata differs in having the spermatheca strongly sclerotized, with the base slightly wider than apex, and the apex obtuse, while in M. sublaevis its apex is acute; sternite IX is longer than wide in M. nudoplagiata, whereas it is as long as wide in M. sublaevis. Also, in M. sublaevis, the setae increase gradually in length towards the median region in sternite VIII, while in M. nudoplagiata sternite VIII bears long setae at the apical margin. For more comments see M. denudata.

Geographical distribution. Recorded from Brazil (Minas Gerais) (Spaeth, 1901). We add two new state records from Brazil: Espírito Santo and São Paulo (Figs. 156, 169).

Material examined (45). Type material. Syntype (Fig. 151) at MM, photographs examined. BRAZIL: Espírito Santo: Barra do São Francisco, I.1955, W. Zikán (3 ex., MNRJ); XI.1956, W. Zikán (1 ex., MNRJ); Colatina: VIII–IX.1937, Mario Rosa (1 ex., MNRJ); Conceição da Barra: 19–24.VIII.1968, C. & T. Elias (1 male, DZUP); Linhares, 23.I.1977, J. Becker (1 male, 3 exs., MNRJ); (Reserva Biológica de Sooretama), III.1953, Pedro Almeida Teles (1 male, MNRJ); V.1953, F.M. Oliveira (1 female, MNRJ); II.1964, A. Maller (1 ex., MNRJ); XI.1965, A. Maller (1 female, 1 ex., DZUP); XII.1967, F.M. Oliveira (1 female, MNRJ); II.1968, F.M. Oliveira (3 males, MNRJ); V.1968, P.A. Teles (2 exs., MNRJ); IX.1968, F.M. Oliveira (1 male, MNRJ); IX.1968, B. Silva (2 exs., MNRJ); X.1968, F. M. Oliveira (1 male, 1 ex., MNRJ); XII.1969, B. Silva (1 male, MNRJ); I.1970 (1 ex., MNRJ); X.1972, Roppa & Alvarenga (1 male, 1 ex., MNRJ); 8–14.VIII.1972, C. & T. Elias (1 ex., DZUP); IX.1977, F.M. Oliveira (1 female, MNRJ); 26.X.1988, F.M. Oliveira (1 ex., MNRJ); Pedro Canário, VI.1970, O. Roppa (1 male, MNRJ); Santa Leopoldina, (Rio Bonito), XII.1966, A. Maller (1 female, DZUP); Santa Teresa, IV.1964, C. & T. Elias (1 ex., DZUP); 26.X.1964, C. & T. Elias (2 exs., DZUP); 7.XII.1964, C. & T. Elias (2 exs., DZUP); 24.IX.1966, C. & T. Elias (1 ex., DZUP); 7–9.XII.1967, C. & T. Elias (1 ex., DZUP); 1–3.II.1968, C. & T. Elias (1 ex., DZUP); 13.I.1970, C. & T. Elias (1 ex., DZUP); São Paulo: Itanhaém, XII.1921 (1 ex., MNRJ).