Zelus ambulans 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 ambulans Stal, 1862

Zelus ambulans Stål, 1862, p. 451, orig. descr.; Stål, 1872, p. 91, cat. (subgenus Diplodus ); Lethierry and Severin, 1896, p. 151, cat.; Champion, 1898, p. 259-260, Tab. XV. fig. 23, 23a, junior syn. of Z. exsanguis ; Maldonado, 1990, p. 327. cat. and junior syn. of Z. exsanguis . stat. rev. (current study).

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

Materials

Type status: Lectotype. Occurrence: catalogNumber: UCR_ENT 00040998 ; occurrenceRemarks: Lectotype of Zelusambulans Stål, 1862 (New Designation by Zhang, Hart & Weirauch, 2016). Verbatim label info: Mexico / Salle / ambulans Stal. / Lectotype Zelusambulans Stal / designated by E. R. Hart / Typus / NHRS-GULI 000000318; recordedBy: Salle; sex: Adult Male; otherCatalogNumbers: NHRS-GULI 000000318; Taxon: scientificName: Zelusambulans; family: Reduviidae; genus: Zelus; scientificNameAuthorship: Stål, 1862; Location: country: MEXICO; stateProvince: unknown; Identification: identifiedBy: G. Zhang; dateIdentified: 2012; Event: eventDate: No date provided; Record Level: institutionCode: NHRS Type status: Paralectotype. Occurrence: occurrenceRemarks: Paralectotype of Zelusambulans Stål, 1862 (New Designation by Zhang, Hart & Weirauch, 2016). Verbatim label info: Mexico / Salle / Allotypus / Zelusambulans Stal; recordedBy: Salle; sex: Adult Male; Taxon: scientificName: Zelusambulans; family: Reduviidae; genus: Zelus; scientificNameAuthorship: Stål, 1862; Location: country: MEXICO; stateProvince: unknown; Event: eventDate: No date provided; Record Level: institutionCode: NHRS Type status: Paralectotype. Occurrence: occurrenceRemarks: Paralectotype of Zelusambulans Stål, 1862. (New Designation by Zhang, Hart & Weirauch, 2016). Verbatim label info: Mexico Coll. Signoret / det. Stal; recordedBy: Signoret; sex: Adult Male; Taxon: scientificName: Zelusambulans; family: Reduviidae; genus: Zelus; scientificNameAuthorship: Stål, 1862; Location: country: MEXICO; stateProvince: unknown; Event: eventDate: No date provided; Record Level: institutionCode: NHMW

Description

Figs 22, 23, 24

Male: (Fig. 22a, b) Medium-sized, total length 12.89-15.19 mm (mean 14.27 mm, Suppl. material 2); slender. COLORATION: Dorsal surface generally brown. Anteocular lobe yellowish-brown to light reddish with darker brown areas on lateral surfaces between compound eyes and antennal insertions, some specimens with dark brown areas on posterodorsal surface. Dorsal surface of postocular lobe dark brown with wide yellowish-brown mid-dorsal and circumocellar areas, remainder of surface yellowish-brown. Rostrum yellowish-brown to reddish-brown, some specimens with segment I and apex of segment II darker reddish-brown. Antennal segments I and II with varying dark brown areas at base and apex, remainder of I and II yellowish-brown to dark reddish-brown, III and IV dark reddish-brown. Anterior lobe yellowish-brown with varying dark brown areas on dorsolateral margins, anterolateral angles of collar, medial sulcus, and small patches at posterodorsal margin. Posterior lobe yellowish-brown with posterior 1/2, except for posterior margin, darkening brown in some specimens. Scutellum yellowish-brown to dark brown. Legs yellowish-brown, apical 1/5 of femora with brown to brownish-black band and apex of tibiae darkening to dark reddish-brown. Hemelytron brown with yellowish-brown costal margins and veins of clavus and corium yellowish-brown except for veins bounding discal cells. Abdominal venter yellowish-brown. VESTITURE: Moderately setose. Short recumbent setae predominating dorsally; short to moderate erect setae over entire body. Recumbent and erect setae over entire sure of head, recumbent setae predominating dorsally. Postocular lobe with recumbent and scattered erect setae over entire surface, recumbent setae more dense dorsally, erect setae more dense lateroventrally. Anterior pronotal lobe with erect and recumbent setae confined to setal tracts dorsally, erect setae laterally. Posterior lobe vestiture consisting of recumbent and scattered erect setae over entire surface. Scutellum with moderate to long, silky setae. Clavus and corium with short recumbent setae, longer near base of clavus. Abdomen with short, stiff, erect setae dorsally, remainder of surface with recumbent and scattered erect setae. STRUCTURE: Head: Cylindrical, L/W = 2.30. Postocular lobe moderately long, posterior 1/2 width constant, lateral margins subparallel. Eey moderately prominent; dorsal margin attaining postocular transverse groove, ventral margin removed from ventral surface of head. Ocellus only slightly elevated. Labium: I: II: III = 1: 1.8: 0.4. Thorax: Anterolateral angle with inconspicuous subtuberculate projection; medial longitudinal sulcus evident only on posterior 1/2, deepening to transverse sulcus of pronotum. Posterior pronotal lobe with finely rugulose surface; disc about same level of, and continuous with, humeral angle; humeral angle armed, with spinous process. Scutellum short; apex blunt to subtuberculate. Legs: Slender. Femoral diameters subequal. Hemelytron: Surpassing apex of abdomen by about length of abdominal segment seven; quadrate cell small; Cu and M of cubital cell subparallel. GENITALIA: (Fig. 23) Pygophore: Elongate ovoid; not expanded laterally in dorsal view. Medial process triangular, relatively broad, moderately long, semi-erect, nearly straight, curved slightly posteriad apically; apex in posterior view blunt, without modification. Paramere: Cylindrical; moderately long, nearly reaching apex of medial process; slightly curved ventrad; apical part enlarged. Phallus: Dorsal phallothecal sclerite elongated, somewhat flattened; medially slightly constricted; apical portion of phallothecal sclerite not distinctly tapered, slightly convex; apex truncate, medially emarginate; posterior margin of foramen broadly concave. Struts attached to dorsal phallothecal sclerite; apically separate, connected by bridge; basally separate. Basal plate arm moderately robust, separate, converging, in lateral view nearly straight, very slightly curved; bridge short; extension of basal plate small and confined to apex of basal plate arm.

Female: (Fig. 22c) Similar to male, except for the following. Larger than male, total length 15.43-18.59 mm (mean 16.55 mm, Suppl. material 2). Generall coloration slightly lighter; legs more or less uniformly colored, apices somewhat reddish, without dark bands.

Diagnosis

Among the species of Zelus luridus group, Z. ambulans has the humeral angle elevated to level of, and continuous with, disc of the posterior pronotal lobe, a condition that is also present in Z. exsanguis , but it can be separated from that species by the yellowish veins on corium, contrasting to the brown corium, whereas the entire corium is more or less uniformly colored in Z. exsanguis .

Among species of the Zelus luridus species group (Fig. 3) males of Z. ambulans can be recognized by the relatively slender medial process (Fig. 23a) and the paramere barely reaching the medial process. The apical enlargement of the paramere is smaller than that in Z. spatulosus and Z. exsanguis , but larger than that in Z. grandoculus , Z. luridus and Z. antiguensis .

Distribution

North and Central America (Fig. 24). Countries with records: Belize, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama.

Taxon discussion

Champion (1898) synonymized Z. ambulans , Z. luridus and Z. cognatus under Z. exsanguis . Hart (1986) recognized all three as valid species, but did not formally reinstate Z. ambulans , probably because it is outside the geographic focus of that particular study. Zelus ambulans remained a synonym of Z. exsanguis in Maldonado (1990) 's catalogue or Reduviidae . We here resurrect Z. ambulans from synonymy. Champion (1898)'s figures of Z. exsanguis actually depict Z. ambulans .

Although this species shows very little morphological variations, color patterns within an area do vary considerably. The dark area at the posterior margin of the longitudinal medial sulcus of the anterior lobe, which serves to easily distinguish Z. ambulans from Z. exsanguis , is relatively constant. Other colors, specifically that of the posterior pronotal lobe and the femoral apices vary from quite light to very dark brown in any given locality. There is also an occasional specimen with somewhat darker hemelytron, but this does not show the wide range of variations of the aforementioned characters.

Most specimens examined have been collected from moderate to high altitudes.