Monastria Saussure, 1864

Tarli, Vitor Dias, Grandcolas, Philippe & Pellens, Roseli, 2018, Taxonomic revision of the genus Monastria Saussure, 1864 (Blattodea: Blaberidae Blaberinae) from the South American Atlantic forest, with the descriptions of five new species, Zootaxa 4524 (3), pp. 359-391 : 364-368

Monastria Saussure, 1864

Diagnosis. Dark brown to black or shiny black cockroaches with pronotum having orange or ochre spots in the middle. Evident sexual dimorphism, males elongated with wings extending beyond the apex of cerci, and females brachypterous. Male pronotum with a characteristic pentagonal transverse shape, lateral margins with sharp angles and a conspicuous small notch. Female pronotum subtriangular with a depression near the margins, and lateral margins with conspicuous small notch or spine. Coxae covered by setae in males, antero-ventral femora margins with spines of equal size. Apical and genicular spines absent. First meta tarsomere of hind leg short and without spines, claws symmetrical and simple, small arolia. L1 present as a single sclerite, its posterior margin almost entirely covered by a crown of small spines, closely packed.

FIGURE 5. Monastria biguttata , ³: A) Habitus, dorsal view; B) Pronotum, dorsal view; C) Head, ventral view; D) Right phallomere, dorsal view; E) Right phallomere, ventral view; F) Left phallomere (L2d), ventral view; G) Median sclerite (L1), dorsal view; H) Median sclerite (L1), detail; I) Left phallomere (L2d), dorsal view. Scales: Habitus= 1cm, Pronotum= 5mm, Head= 2 mm, all others = 1 mm.

Generic description. Male (Fig. 5). Medium size (40‾ 55 mm). Head subtriangular; eyes extending antero-lat- erally beyond the antennal socket (Fig. 5C); interocular space narrow at its closest distance and smaller than the one between the antennal sockets (0.8‾ 1.8 mm). Antennae not surpassing the apex of the tegmina, filiform and setose from the eighth flagellar segment. First flagellar segment larger than the pedicel. Maxillary palps with the fifth segment more dilated and very tomentose. Pronotum pentagonal with fore margin strongly arcuate, hind margin nearly very weakly arcuate, and a specific black coloration pattern in the central region (Fig. 5B). Tegmina developed, extending beyond the apex of cerci; marginal field short and slightly concave; scapular field tapering toward apex; mid-field discoidal, extended apically, slightly angular along veins; subcostal vein with a carina on its ventral surface, anal veins reaching the posterior border (Fig. 5A). Wing marginal field narrow, subcostal vein reaching basal third of scapular field; cubital vein with numerous complete and few incomplete veins; apical triangle absent. Setae in the dorsal region of the three thoracic segments and in the first abdominal segment. Fore-femora ventroanterior margins with 16 spines of the same size arranged side by side, the last one near the apex directed outward, ventro-posterior margins with 3 spines distributed in uniform spaces along the fore-femora and the last one near the apex. Middle legs ventro-anterior margins of with 3 or 4 spines, the last one close to the apex. Tarsomeres 1-4 with pulvilli, the pulvillus of the first metatarsomere very long, covering more than half of the length of metatarsomere; tarsal claws simple and symmetrical; small arolium present. First abdominal tergite unspecialized. Supra-anal plate quadrangular, posterior border bilobated with a strong median incision. Cerci short, cylindrical, with different coloration in the last segments. Subgenital plate slightly asymmetric. Internally, attached to this plate, a membranous pouch with genital sclerites L1 (Figs. 5G, H), L2d (Figs. 5F, I) and R (right phallomere) (Figs. 5D, E). Sclerite L1 long and thin with the apical part distinct, quite sclerotized and the left branch tooth-shaped; central portion with a small posteriror projection and a branch on the right side directed upwards; apical region with a crown of sclerotized spines. Sclerite L2d hook-shaped, like in most species of Ectobiidae and Blaberidae . Distal area elongated with subapical notch. Sclerite R (right phallomere) formed by sclerotized regions R2, R3d, R 3v and N (Figs. 5D). Sclerite R2 (“cleft”) curved, deep and directed upward. Sclerite R3d wide and elongated longitudinally with a dorsal part reduced and a large ventral one in the distal region. Sclerite R 3v with a flattened and inverted v shape in ventral view; rounded anterior lateral apex, and short caudal branch (Fig. 5E).

Female (Figs. 4, 6A–D). Species of medium size (30‾ 45 mm). Head rounded, with wide interocular space mea- suring 1/2 the distance between the antennal sockets (2.0‾ 3.1 mm). Eyes reniform with straight interocular margin. Antennae reaching the apex of the tegmina, filiform and setose from the eighth flagellar segment. Ocelli developed and deflected. Front broad and frontal suture with a cuticular invagination (Fig. 6D). Pronotum subtriangular with anterior region rounded and slightly concave near the margins, dorsal region rough with striae, lateral angles rounded ending in a corner, posterior margin slightly curved in the median region (Fig. 6B). Brachypterous. Tegmina truncated with a marked curvature towards the interior and not extending further than the second abdominal tergite; wings much shorter and undeveloped (Fig. 6A). Legs short and robust. Fore femora ventro-anterior margins with 13 spines of the same size, the last one close to the apex; ventro-posterior margins with 4 spines, the last one close to the apex. Middle legs ventro-anterior margins with 4 spines, the last one close to the apex. Supra-anal plate bilobed with a small median incision, each lobe with slightly rounded lateral and straight posterior margin (Fig. 6C). Tergites with slightly rounded lateral angles (Fig. 6A).

Juvenile stages. Juveniles of both sexes are oval, almost rectangular with a body length and width ratio = 1,7:1. Beige to light brown, uniformly colored, the dorsal surface of pronotum and tergites is very rough (Fig. 7), covered by thorn-like cuticular microsculptures, often more abundant at their hind margins. (Fig. 3A). Head, eyes, antennae, legs, supra-anal and subgenital plate very similar to those in adults (Fig. 7E).

Habitat and Behavior. Specimens of Monastria were observed in a large array of forest ecosystems, ranging from semi-deciduous forests at the Northeast to the humid montane forests in the central region and the Araucaria forests in the South. All specimens were observed and collected in the forest understory on the underside of dead trunks of various sizes, as it was described in details for M. biguttata ( Pellens & Grandcolas, 2003) . Very often found grasping on the underside of the bark or the wood of dead trunks, immediately freezing when disturbed. The body of the juveniles are covered by fine particles of the substrate where they are found, which are attached to the tegument structures (Fig. 7). Adult males have never been seen flying, even if they look able to do so with their large and mobile wings. As any blaberid species, they are ovoviviparous, the females retract the large oothecae in the brood sac. Juvenile stages are often observed in groups that remain near each other until adulthood.

FIGURE 6. Figs. A-D, Monastria biguttata , ♀: A) Habitus, dorsal view; B) Pronotum, dorsal view; C) Supra-anal plate, dorsal view; D) Head, ventral view. Figs. E-H, Monastria similis , ♀: E) Habitus, dorsal view; F) Pronotum, dorsal view; G) Supra-anal plate, dorsal view; H) Head, ventral view. Scales: Habitus= 1cm, Pronotum= 5mm, Supra-anal plate= 5mm, Head= 2 mm.

FIGURE 7. Male juveniles of Monastria in different stages of development. Scales: Habitus= 5mm. Note the rough surface covered by particles in all stages.