Schraderiellus falcatus Roell & Campos

Roell, Talita & Campos, Luiz Alexandre, 2018, Phylogeny and revision of Schraderiellus Rider, 1998 with the description of five new species (Hemiptera, Pentatomidae, Discocephalinae, Ochlerini), Zootaxa 4508 (1), pp. 47-67 : 62-63

Schraderiellus falcatus Roell & Campos , sp. nv.

( Figs. 3M–N , 5 S–U , 6F , 7F )

Etymology: The name refers to the parameres which are strongly curved posteriorly.

Latin = falcatus , sickle-shaped, hooked, curved.

Holotype: male, here designated. COSTA RICA, Puntarenas, Península de Osa near Cabo Matopalo, 6.21.03 (NMPC) Deposited in: NMPC

Paratype: PANAMA, V. de Chiriqui, 25-4000 ft, Champion: 1♂ (BMNH). Deposited in: BMNH.

Description. Dark brown; some specimens with yellow-orange spots on connexivum and on anterior and posterior margins of scutellum. Coxae, trochanter, and femora brown. Tibiae and tarsi slightly yellowish to brown ( Fig. 3M–N ).

Male. Measurements (n=2): head length 2.56 ± 0.05 (2.52–2.60); width 3.12 ± 0.00 (3.12–3.12); pronotum length 3.13 ± 0.0 (3.13–3.13); width 6.17 ± 0.00 (6.17–6.17); scutellum length 5.30 ± 0.00 (5.30–5.30); width 3.50 ± 0.10 (3.50–3.50); abdomen length 4.97 ± 0.40 (4.97–4.97); width 6.21 ± 0.25 (6.04–6.39); length of antennal segments: I 1.24 ± 0.00 (1.24–1.25); II 1.14 ± 0.05 (1.11–1.18); III 2.02 ± 0.02 (2.01–2.04); IV 2.18 ± 0.02 (2.17– 2.20); V?; length of labial segments: I 1.76 ± 0.00 (1.76–1.76); II 3.27 ± 0.17 (3.15–3.40); III 2.35 ± 0.13 (2.26– 2.45); IV 2.61 ± 0.12 (2.52–2.70); total length 13.10 ± 0.44 (12.79–13.41).

Genitalia. Pygophore subglobular, brown, posterolateral angles strongly divergent, apices rounded, dorsally projected ( Fig. 5 S–U ). Parameres yellowish, moderately divergent, little longer than segment X, strongly curved posteriorly, cylindrical digitiform, apices slightly flattened with subapical denticle ( Figs. 5 S–U , 6F ). Segment X subcylindrical, basal portion membranous forming a concave line on limit with sclerotized area; ventrally sclerotized ( Fig. 5 S–U ). Phallotheca globose, vesica sinuous, subequal to phallotheca in length ( Fig. 7F ).

Distribution: Costa Rica, Panama.

Female unknown.

Comments. The species of Schraderiellus have a very similar body morphology, and though some can be easily distinguished for the color pattern (e.g. S. luridomaculatus sp. nv.), there is intraspecific color variation in most species. Moreover, species sharing similar color may differ in genital morphology as in S. luteipedis sp. nv. and S. falcatus sp. nv. . These two species have tibiae and tarsi similar in color, but differ in the male genital morphology, mainly the parameres (spatulated in S. luteipedis sp. nv. and cylindrical in S. falcatus sp. nv.). Most species are reliably diagnosed only by the few and sometimes subtle differences in both the female and male genitalia as described in the Taxonomy section. On the other hand, groups of species can be recognized for sharing genital characteristics. The convex posterior margin of gonocoxites VIII is observed in: S. cinctus , S. luteipedis , and S. luridomaculatus , whilst S. rufilineatus , S. luridomaculatus , and S. luteipedis have an apparently similar pyghophore, especially the spatulated parameres. The lack of information on internal genitalia in S. luridomaculatus , S. brevicolis , and S. falcatus , and on female genitalia at all in the last two, hinders any considerations on the phylogenetic role of genital morphology in Schraderiellus .

Figures

FIGURE 3. Species of Schraderiellus, dorsal and ventral habitus. A, B, S. hughesae; C, D, S. cinctus; E, F, S. luridomaculatus sp. nv.; G, H, S. rufilineatus sp. nv.; I, J, S. luteipedis sp. nv.; K, L, S. brevicolis sp. nv.; M, N, S. falcatus sp. nv.. Scale bars = 1mm.

FIGURE 5. Pygophores in posterior, dorsal and lateral views. A–C, S. hughesae; D–F, S. cinctus; G–I, S. luridomaculatus sp. nv.; J–L, S. rufilineatus sp. nv.; M–O, S. luteipedis sp. nv.; P–R, S. brevicolis sp. nv.; S–U, S. falcatus sp. nv.. Abbreviations: dr, dorsal rim; il, inferior layer; p1, dorsal projection of the posterolateral angles; p2, basal projection of the posterolateral angles; pa, posterolateral angles; par, parameres; vr, ventral rim; X, segment X. Scale bars = 1mm.

FIGURE 6. Parameres; dorsal, posterior, inner lateral and external lateral respectively. A, S. hughesae; B, S. cinctus; C, S. rufilineatus sp. nv.; D, S. luteipedis sp. nv.; E, S. brevicolis sp. nv.; F, S. falcatus sp. nv.. Scale bar: 0.5mm.

FIGURE 7. Male internal genitalia (phallus), lateral view. A, S. hughesae; B, S. cinctus; C, S. rufilineatus sp. nv.; D, S. luteipedis sp. nv.; E, S. brevicolis sp. nv.; F, S. falcatus sp. nv.. Scale bars = 0.5mm