Zelus janus Stal , 1862

Zhang, Guanyang, Hart, Elwood R & Weirauch, Christiane, 2016, A taxonomic monograph of the assassin bug genus Zelus Fabricius (Hemiptera: Reduviidae): 71 species based on 10,000 specimens, Biodiversity Data Journal 4, pp. 8150-8150 : 8150

Zelus janus Stal, 1862

Zelus janus Stål, 1862, p. 452, orig. descr.; Stål, 1872, p. 90, cat. (subgenus Diplodus ); Lethierry and Severin, 1896, p. 152, cat.; Champion, 1898, (in part), p. 257-258, Tab. XV. fig. 19, note, fig. and senior syn. of Z. litigiosus ; Fracker, 1913, p. 239, 240, key and list (subgenus Diplodus ); Fracker and Bruner, 1924, p. 170-171, note; Wygodzinsky, 1949a, p. 49, checklist; Hart, 1986, p. 543, redescription, lectotype desig., note, key and fig.; Maldonado, 1990, p. 328, cat.

Diplodus janus : Uhler, 1886, p. 24, checklist; Walker, 1873, p. 124, cat.

Materials

Type status: Lectotype. Occurrence: catalogNumber: UCR_ENT 00041005 ; occurrenceRemarks: Lectotype designated by Hart (1986). Verbatim label info: Mexico / Salle / janus Stal / Lectotype Zelusjanus Stal / designated by E.R.Hart / Typus / NHRS-GULI 000000331; recordedBy: Salle; sex: Adult Male; otherCatalogNumbers: NHRS-GULI 000000331; Taxon: scientificName: Zelusjanus; family: Reduviidae; genus: Zelus; scientificNameAuthorship: Stål, 1862; Location: country: MEXICO; Record Level: institutionCode: NHRS Type status: Allolectotype. Occurrence: occurrenceRemarks: Allolectotype designated by Hart (1986).; recordedBy: Salle; sex: Adult Female; Taxon: scientificName: Zelusjanus; family: Reduviidae; genus: Zelus; scientificNameAuthorship: Stål, 1862; Location: country: MEXICO; Record Level: institutionCode: NHRS Type status: Paralectotype. Occurrence: occurrenceRemarks: Paralectotype designated by Hart (1986).; recordedBy: Salle; sex: Adult Male; Taxon: scientificName: Zelusjanus; family: Reduviidae; genus: Zelus; scientificNameAuthorship: Stål, 1862; Location: country: MEXICO; Record Level: institutionCode: NHRS Type status: Paralectotype. Occurrence: occurrenceRemarks: Paralectotype designated by Hart (1986).; recordedBy: Salle; sex: Adult Female; Taxon: scientificName: Zelusjanus; family: Reduviidae; genus: Zelus; scientificNameAuthorship: Stål, 1862; Location: country: MEXICO; Record Level: institutionCode: NHRS Type status: Paralectotype. Occurrence: occurrenceRemarks: Paralectotype designated by Hart (1986). Bears labels: Mexico / CoIl. Signoret / Janus, det. Stal.; recordedBy: Signoret; sex: Adult Male; Taxon: scientificName: Zelusjanus; family: Reduviidae; genus: Zelus; scientificNameAuthorship: Stål, 1862; Location: country: MEXICO; Record Level: institutionCode: NHMW Type status: Paralectotype. Occurrence: occurrenceRemarks: Paralectotypes designated by Hart (1986). Bear labels: Mexico / CoIl. Signoret / Janus, det. Stal.; recordedBy: Signoret; individualCount: 3; sex: Adult Female; Taxon: scientificName: Zelusjanus; family: Reduviidae; genus: Zelus; scientificNameAuthorship: Stål, 1862; Location: country: MEXICO; Record Level: institutionCode: NHMW

Description

Figs 103, 104, 105

Male: (Fig. 103a, b, e) Large, total length 15.44-19.55 mm (mean 17.63 mm, Suppl. material 2); robust. COLORATION: Dorsal surface nearly uniformly brown; distal part of corium sometimes yellowish or reddish. Lateral and ventral surfaces yellowish-brown; dark brown stripe along posterior margin of abdominal segment, single dark spot anterolaterally on each segment. Legs with indistinct banding or completely dark brown. VESTITURE: Sparsely setose. Similar to that in Z. armillatus ; adpressed setae denser; long, erect setae on head and pronotum relatively shorter. STRUCTURE: Head: Cylindrical, L/W = 2.28. Postocular lobe long; in dorsal view anteriorly gradually narrowing, posterior portion constant, slightly narrower. Eye smallish; lateral margin much wider than postocular lobe; dorsal and ventral margins removed from surfaces of head. Labium: I: II: III = 1: 1.3: 0.3. Basiflagellomere diameter smaller than that of pedicel. Thorax: Anterolateral angle bearing small projection; medial longitudinal sulcus shallow near collar, deepening posteriorly. Posterior pronotal lobe with finely rugulose surface; disc about same level as humeral angle; humeral angle armed, with short tuberculate processes. Scutellum short; apex angulate. Legs: Robust, metafemoral diameter smallest. Hemelytron: Slightly surpassing apex of abdomen, not more than length of abdominal segment seven; quadrate cell large and broad; Cu and M of cubital cell converging towards R. GENITALIA: (Fig. 104) Pygophore: Ovoid; slightly expanded laterally near base of paramere in dorsal view; posteriorly expanded sac-like sclerite between paramere and medial process. Medial process cylindrical; slender; short; semi-erect; slightly curved; apex in posterior view truncate, with small sharp lateral projections. Paramere: Cylindrical; short, not reaching apex of medial process; directed posteriad; not distinctly curved; apical part not enlarged. Phallus: Dorsal phallothecal sclerite shield-shaped; lateral expansion arising close to base; apical portion of phallothecal sclerite not distinctly tapered, flat, laterally angulate; apex truncate, not emarginate; posterior margin of foramen broadly concave, medially deeper. Struts attached to dorsal phallothecal sclerite; apically separate, connected by bridge; basally separate. Basal plate arm moderately robust; separate; converging; in lateral view slightly curved; bridge short; extension of basal plate expanded onto arm.

Female: (Fig. 103c, d) Similar to male, except for the following. Larger than male, total length 19.01-21.96 mm (mean 20.53 mm, Suppl. material 2). Whitish area on distal part of corium smaller, almost non-existent in some specimens; posterior pronotal lobe, corium and clavus entirely yellowish-brown in some specimens.

Diagnosis

Among closely related species in the Zelus armillatus species group with overlapping distribution ranges, Z. janus is the only species with the humeral angle elevated to about same level as the disc of the posterior pronotal lobe. This species is much larger than and the coloration different from two other species sharing this feature, Z. exsanguis and Z. ambulans , both from a different species group. Other characters useful for diagnosis include the dorsal surface usually mostly brown and the lateral and ventral surfaces yellowish-brown; the abdominal segment each with single dark spot anteriorly; and in males the medial process narrower, relatively short.

Distribution

Southern Texas to Central America (Fig. 105). Countries with records: USA (Texas), Belize, Guatemala, Honduras, Mexico and Nicaragua.

Taxon discussion

It is rather difficult to distinguish Z. janus from Z. armillatus on the basis of the male genitalia alone, the only two species in the genus where such distinction cannot be made. As the humeral angle of the posterior pronotal lobe are raised to the level of and are nearly continuous with the disc, however, it is quite easy to separate specimens of these species. There is further divergence in coloration and pattern between the two which may be seen in the descriptions of these species. A sympatric and closely related species, Z. litigiosus , also has the disc elevated above the humeral angle and is easily distinguished. Zelus janus has a somewhat more uniform brown dorsal coloration, whereas the color pattern in Z. litigiosus is more variable.