Heilus bistigma ( Hustache, 1938 )

Lira, Aline De Oliveira, Sousa, Wesley Oliveira De, Rosado-Neto, Germano Henrique, Santos, Geane Brizzola Dos & Marques, Marinêz Isaac, 2020, A review of the South American species of Heilus Kuschel, 1955 (Curculionidae Molytinae: Molytini: Hylobiina) with emphasis on those from Brazil, Zootaxa 4861 (2), pp. 151-187 : 178-180

Heilus bistigma ( Hustache, 1938)

( Figs. 17 , 18L , 19K , 20K , 21K , 22K , 23L )

Heilipus bistigma Hustache, 1938:339 (description); Blackwelder 1947:817 (catalog); Wibmer & O’Brien 1986:145 (checklist).

Heilus bistigma: Kuschel 1955:297 (combination).

Type material. Heilipus bistigma Hustache, 1938 : we examined an image of a syntype ( Fig. 17 ), undetermined sex, bearing the following label: “Jatahy; H. bistigma in.; TYPE; Muséum Paris 1949 Coll. A. Hustache; SYNTYPE; MNHN EC8366”.

Redescription. Length (pronotum and elytra) of males and females 8.43 to 9.71/ 8.43 to 10.86 mm, respectively. Integument bright, varying from dark brown to black. Rostrum about 1.2 times longer than pronotum; about 4.7 longer than basal width in females and about 5.4 times longer in males. Thorax. Pronotum ( Figs. 17 A–B) about 1.5 times wider than long, rounded sides, rounded granules more prominent on sides than at center, yellow scales distributed between granules; fine, yellowish, black, and gray condensed scales; whitish setae stripes in center of pronotum adjacent to scutellum, which is completely covered by gray scales. Elytra ( Figs. 17 A–B) about 1.6 times longer than wide, densely covered by high, umbilicate granules, each one with short scale, sometimes not distinct, distributed in interstriae; interstriae flat; humeri prominent, covered with small granules; apical elytral calli high, covered with granules; diagonal band of gray scales distributed from humeri to central region of elytra, interrupted by cluster of velvety black scales forming a macula between striae 2 and 5, transverse band of gray scales just below macula extending to apical elytral calli; apex of elytra with clusters of white setae; elytral striae well-marked, with moderately coarse punctures. Male genitalia. Median lobe of aedeagus ( Fig. 18L ) about 1.2 times shorter than median lobe apodemes, rounded apex with elongate, centralized setae; narrow sides near apex, widening toward apodemes; internal sac sclerite ( Fig. 19K ) with curved projections and strongly acuminate, with tiny spicules condensed in these projections. Tegmen ( Fig. 20K ) with dorsal lobes larger than manubrium separated by about 2.5 times their length. Female genitalia ( Fig. 21K ). Coxites with short, dense setae at apex. Spermathecal duct short inserted near end of bursa copulatrix. Spermathecal capsule ( Fig. 22K ) well-curved, ramus and collum prominent, and cornu robust.

Dimensions (mm). Males/females, respectively. TBL: 5.9–6.8/5.9–7.6; TRL: 2.6–2.8/1.7–3.7; MHx: 3.3– 4.0/3.7–4.6; RAW: 0.5/0.5–0.7; RBW: 0.5/0.5–0.7; IO: 0.4/0.4–0.6; PnL: 1.9–2.1/2.0–2.4; PnMW: 2.9–3.0/2.7–3.6; PnBW: 2.6–2.9/2.6–3.4; EL: 6.4–7.9/6.3–8.0; EW: 3.9–4.4/4.1–5.0.

Non-type material examined. In total, 21 specimens were examined. BRAZIL: Espírito Santo: Santa Teresa , 1♀, 5.i.1967, C.T. & C. Elias ( DZUP) ; Rio de Janeiro: Corcovado , 1♂, 18.ix.1961, J.S. Moure, Alvarenga & Seabra ( DZUP) , 1♀, 3.xii.1965, Moure & Seabra ( DZUP) , 1♂, ix.1958, Alvarenga & Seabra ( DZUP) , 1♀, ix.1969, Alvarenga & Seabra ( DZUP) , 1♀, x.1957, M. Alvarenga ( MZSP) , 1♀, x.1958, M. Alvarenga ( MZSP) , 2♀, 1♂, x.1961, M. Alvarenga ( MZSP) , 2♀, 1♂, xi.1958, M. Alvarenga ( MZSP) , 1♀, xi.1961, M. Alvarenga ( MZSP) , 1♂, xii.1957, M. Alvarenga ( MZSP) , 1♀, xii.1958, M. Alvarenga ( MZSP) , Floresta da Tijuca , 1♂, ii.1957, M. Alva- renga ( MZSP) , 1♂, vii.1957, M. Alvarenga ( MZSP) ; Paraná: Arapongas , 1♂, ii.1952, A. Maller ( MNRJ) ; Santa Catarina: Nova Teutônia , 1♀, x.1974, Fritz Plaumann ( DZUP) , 1♀, xii.1973, Fritz Plaumann ( DZUP) .

Geographical distribution. According to Wibmer & O’Brien (1986), H. bistigma occurs in Bolivia, Paraguay, Brazil, and Argentina . The examination of the material allowed its distribution to be expanded in Brazil to the Atlantic Forest, in Espírito Santo, Rio de Janeiro, Paraná, and Santa Catarina states ( Fig. 23L ).

Associated plants. Unknown.

Remarks. Heilus bistigma differs from the other species by the following characters: diagonal stripes of white setae from the humeri to the median region of the elytra, with a black macula of irregular shape in the central region, and a transverse strip of white setae on the posterior margin of the apical elytral calli.

Figures

FIGURE 17. Syntype Heilus bistigma. A. dorsal view. B. lateral view. C. labels. The copyright of images belongs to MNHN.

FIGURE 18. Aedeagus. A. Heilus inaequalis, dorsal view. B. Heilus inaequalis, lateral view. C. Heilus pupillatus. D. Heilus tuberculosus. E. Heilus rufescens. F. Heilus freyreissi. G. Heilus myops. H. Heilus faldermanni. I. Heilus ochrifer. J. Heilus fasciculatus. K. Heilus iniquus. L. Heilus bistigma. Legends: median lobe (ml), internal sac sclerite (sc), median lobe apodemes (mla).

FIGURE 19. Internal sac sclerite. A. Heilus inaequalis. B. Heilus pupillatus. C. Heilus tuberculosus. D. Heilus rufescens. E. Heilus freyreissi. F. Heilus myops. G. Heilus faldermanni. H. Heilus ochrifer. I. Heilus fasciculatus. J. Heilus iniquus. K. Heilus bistigma.

FIGURE 20. Tegmen. A. Heilus inaequalis. B. Heilus pupillatus. C. Heilus tuberculosus. D. Heilus rufescens. E. Heilus freyreissi. F. Heilus myops. G. Heilus faldermanni. H. Heilus ochrifer. I. Heilus fasciculatus. J. Heilus iniquus. K. Heilus bistigma. Legends: dorsal lobe (ld), manubrium (m).

FIGURE 21. Female genitalia. A. Heilus inaequalis. B. Heilus pupillatus. C. Heilus tuberculosus. D. Heilus rufescens. E. Heilus freyreissi. F. Heilus myops. G. Heilus faldermanni. H. Heilus ochrifer. I. Heilus fasciculatus. J. Heilus iniquus. K. Heilus bistigma. Legends: coxite (cx), styli (st), common oviduct (co), bursa copulatrix (bc), spermathecal duct (spd), spermathecal capsule (sp), spermathecal gland (spg).

FIGURE 22. Spermathecal capsule. A. Heilus inaequalis. B. Heilus pupillatus. C. Heilus tuberculosus. D. Heilus rufescens. E. Heilus freyreissi. F. Heilus myops. G. Heilus faldermanni. H. Heilus ochrifer. I. Heilus fasciculatus; J. Heilus iniquus; K. Heilus bistigma. Legends: cornu (cr), collum (cl), ramus (ra).

FIGURE 23. Geographical distribution of Heilus species based on labels information. A. South America Brazilian biomes and Paraguayan and Argentine ecoregions. B. Heilus inaequalis; C. Heilus pupillatus; D. Heilus tuberculosus; E. Heilus rufescens; F. Heilus freyreissi; G. Heilus myops; H. Heilus faldermanni; I Heilus ochrifer; J. Heilus fasciculatus; K. Heilus iniquus; L. Heilus bistigma.