Zethus (Zethus) wileyi Stange

Lopes, Rogério B., Noll, Fernando B. & Stange, Lionel A., 2017, Zethus (Zethus) wileyi (Hymenoptera, Vespidae, Eumeninae), a new species with its own species-group, Zootaxa 4231 (1), pp. 137-144 : 138-141

Zethus (Zethus) wileyi Stange , sp. nov.

( Figs 1 , 3 a, c, e, g, 4)

Diagnosis. Stem of T2 longer than stem of T1; F11 of male falciform, long and sharp; submedian carina present. The configuration of the digitus (see below) is unique in the genus so far.

Description. MALE. Coloration. Black. Following markings yellow: ventral half of clypeus; stripes on scape; small spot above each antennal socket; small spot on humeral angle; small spots on tegula and parategula apically; basal spot on fore femora; basal and apical spot on fore tibiae; stripes on mid and hind tibiae; subapical band on T1 extending forwards laterally; narrow subapical bands on T2 and T3 and S2 and S3. Brownish: tegula; tibiae; tarsi; S1; base of T2 and S2; S5–S7 (T4 and S4 not visible); wings hyaline with brown costa.

Structure. Clypeus wider than high with concave apical margin; F-XI long, sickle shaped, very sharp; pronotal carina lamellar dorsally; pretegular carina present but inconspicuous; parategula vey short; two midtibial spurs; propodeal aperture slit-like, closed dorsally; propodeum with narrow and deep concavity; T1 expands gradually; stem of T2 longer than stem of T1, with gradual expansion both on dorsal and lateral view.

Sculpture. Tyloids on F6–F9; clypeus with moderate shallow macropunctures intercalated by smooth areas; frons striatopunctate for short extension, becoming densely punctate all the way to vertex; most of mesosoma densely macropunctate intercalated by moderate to sparse micropunctation; notauli present posteriorly; propodeum shagreened laterally until lateral carina, after which becomes sharp striae dorso-laterally that develop into coarse reticulation on posterior face and fades into feeble striae and shagreened on concavity; lateral and submedian carina well developed, extending little after half height of propodeum; media carina of propodeum well developed on central half; T1 moderately macropunctate with sparse micropuntation; T2 densely micropunctate with feeble and inconspicuous medium sized punctures on center and aggregation of well-marked shallow and dense macropunctures apically, especially on the sides; S2 with sparse macropunctures intercalated by smooth areas basally becoming more like T2 halfway through.

Pilosity. Thin, erect, golden densely setae on most of head and mesosoma; long sparse setae ventrally on F1– F9; clypeus with curved sparse setae; thicker, longer and denser, whitish pilosity on ventrally on mesosoma and coxae metanotum, propodeum and base of petiole; moderate to sparse thin, golden, curved setae on T1; T2 with short dense tomentum; S-II with pilosity, similar to that of T1, basally becoming very dense apically.

Fore wing length: 8,6 mm; stem of T2 a little under two times as long as wide.

Genitalia. Aedeagus: basal plate with rounded apex in ventral view; apodema rounded, bending approximately 90° from base to apex; ventral lobe semi-circular with posterior margin reflexed and toothed; body margin nearly parallel with apex weakly bilobate and reflexed ventrally. Volsellar body very wide and nearly perpendicular to axis of gonocoxite. Volsellar lamella with thick setae directed apically, thin ones directed basally. Cuspis large, completely covered by very thick scale-like setae, except for root; large basal projection and medial lobe well indicated with conules. Digitus large and complex; distal lobe dorsally folding, apparently forming two superposed lamellae; more sclerotized on folding region and more strongly so on apical margin (obs: these were probably connected, but were broken during extraction/handling of the genitalia); basal lobe reflexed behind from base of the root, marked by conules visible even from inner view.

FEMALE. Unknown.

Type material. Holotype, ♂ ( FSCA): PANAMA, CZ, Gamboa , May 10 ’72 [10.v.1972], R & E Froeschner.

Etymology. This species is dedicated to Jim Wiley, former curator of Hymenoptera at the FSCA in recognition of his Zethus collecting in the Bahamas and outstanding curating of the Zethus collection.

Systematics. The matrix (Table 1) used in the search for trees with k = 2,343750 returned two trees, whose strict consensus result in the collapsing of one node. In this consensus ( Fig. 2 ), Z. wileyi is the sister species-group to the Z. hilarianus species-group. This relation is strongly supported by symmetric resampling.

In these circumstances, one could simply place the new species described here as the earliest derived lineage within the Z. hilarianus species-group. However, some characters disagree (two are unknown since they are observable only in females) with the given diagnosis of the species-group ( Lopes et al., 2015). Although, there are three synapomorphies grouping the new species with the Z. hilarianus species-group, only one of these represents a diagnostic character for the species-group ( Table 2 ). The anterior margin of S1 can be interpreted as a midway state, with a larger straight portion, in contrast with a semi-elliptic aspect from other species, such as Z. productus Fox, 1899 (see Lopes et al., 2015: 428, Fig. 4 L). Furthermore, Z. wileyi shows six autoporphies ( Fig. 2 ), of which four are unique and two are homoplastic, demonstrating that it is a well-defined and distinct lineage.

In this way, it is better to maintain a well-supported, well-delimited species-group as it is rather than expanding it to comprise one species that would lead to an extension of its diagnostic amplitude and blurring of its delimitation.

TABLE]. Character matrix useđ in analysis.

Species Characters * Synapomorphy of Z. hilarianus species-group according to Lopes et al. (2015).

Figures

FIGURE 1. Zethus wileyi sp. nov., ♂, holotype. a. Head; b. Habitus. Scale = 1. 0 mm

FIGURE 2. Consensus from two trees found in tree search with implied weighting (k = 2,343750). Numbers in boxes represent GC values of symmetric resampling. Circles represent characters supporting each clade: black ones represent unique synapomorphies and white ones, homoplasies.

FIGURE 3. Zethus spp. Zethus wileyi sp. nov., ♂, holotype (a, c, e, g); Z. smithii (b, d, f, i); Z. hilarianus (h). a – b. Antennal hook, lateral inner view. c – d. Right fore leg, oblique lateral view. e – f. Base of S 1, ventral view. g – i. Propodeum, posterior view. Arrows point submedian carinas. Arrow head shows dorsal propodeal aperture. Scales: a-g = 1,0 mm; h-i = 0,5 mm.

FIGURE 4. Male genitalia of Zethus wileyi sp. nov. a _ b. Aedeagus, ventral (a) and lateral (b) view. c. Volsella picture, inner view. d. Volsella drawing, with delimited regions, inner view. e. Digitus, inner view. f. Digitus, inner view, inner fold obscured to show details beneath it. g. Cuspis. bld, basal lobe of digitus; bpc, basal projection of cuspis; c, cuspis; d, digitus; dld, distal lobe of digitus; mlc, medial lobe of cuspis; rc, root of cuspis; rd, root of digitus; vb, volsellar body; vm, volsellar membrane. Arrow head points region the folding occurs. Scale = 0,5 mm.