Zelus cervicalis Stal , 1872

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

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Zelus cervicalis Stal , 1872


Zelus cervicalis Stal, 1872 View in CoL

Zelus cervicalis Stål, 1872, p. 90, orig. descr. (subgenus Zelus ); Uhler, 1876, p. 61, list (reprint); Uhler, 1886, p. 24, checklist; Lethierry and Severin, 1896, p. 151, cat.; Champion, 1898, p. 255, cat.; Banks, 1910, p. 16, cat.; Torre-Bueno and Engelhardt, 1910, p. 150, note; Van Duzee, 1912, p. 324, senior syn. of Z. marginata (Provancher); Fracker, 1913, p. 239, 240, key and list (subgenus Zelus ); Torre-Bueno, 1913, p. 60, list; Barber, 1914, p. 506, list; Van Duzee, 1916, p. 30, checklist (subgenus Zelus ); Van Duzee, 1917, p. 260, cat. (subgenus Zelus ); Dozier, 192,0 p. 357, list; Blatchley, 1926, p. 569, key and note (subgenus Zelus ); Readio, 1927, p. 169, 170, key and descr.; Wygodzinsky, 1949a, p. 48, checklist; Elkins, 1951, p. 410, list; Sibley, 1951, p. 92, list; Kelton, 1968, p. 1071, note; Snow, 1906, p. 180, list; Van Duzee, 1909, p. 177, list; Osborne and Drake, 1915, p. 531, note; Brimley, 1938, p. 73, list; Elliott, 1938, p. 39, list; Tenhet and Howe, 1939, p. 24, note; Drew and Schaeffer, 1962, p. 106, list; Oliver, 1964, p. 316, note; Whitcomb and Bell, 1964, p. 22, List and note; Hart, 1986, p. 542-543, lectotype desig., redescription, note, fig. and key; Maldonado, 1990, p. 326, cat.

Evagoras marginata Provancher, 1887, p. 182-183, orig. descr.; Van Duzee, 1912, p. 324, junior syn. of Z. cervicalis ; Kelton, 1968, p. 1071, note.

Zelus marginatus : Lethierry and Severin, 1896, p. 152, cat.; Banks, 1910, p. 16, cat.

Zelus pictipes Champion, 1898, p. 255, Tab. XV, fig. 14, orig. descr, and fig.; Fracker, 1913, p. 239, 240, key and list; Van Duzee, 1916, p. 30, checklist (subgenus Zelus ); Van Duzee, 1917, p. 259, cat. (subgenus Zelus ); Readio, 1927, p. 169, 170, key and descr.; Wygodzinsky, 1949a, p. 50, checklist; Snow, 1906, p. 180, list; Elkins, 1951, p. 410, list; Sibley, 1951, p. 92, list; Drew and Schaeffer, 1962, p. 106, list; Hart, 1986, p. 542, lectotype desig. and junior syn. of Z. cervicalis .


Figs 48, 49, 50

Male: (Fig. 48a, b, c) Medium-sized, total length 9.81-13.08 mm (mean 11.78 mm, Suppl. material 2), very slender, body length/width=6.2. COLORATION: Yellowish-brown to dark brown, some specimens with dark spots or bands on legs. Anteocular lobe yellowish-brown to reddish-brown, dark brown between eye and antennal insertion, some specimens with dark brown mid-dorsal areas. Dorsum of postocular lobe dark brown, variably shaped medial longitudinal line and area between ocelli and eye yellowish-brown, ventral surface yellowish-brown. Labial segments I & II yellowish-brown; segment III reddish to dark brown. Antennal segments brown, sometimes scape darker on dorsal surface or pedicel darker apically. Anterior pronotal lobe yellowish-brown to brown, collar and setal tracts darker, some specimens with dark brown spot on pro-episternum. Posterior pronotal lobe yellowish-brown to brown. Pleura yellowish-brown. Sternites yellowish-brown; meso-sternum with dark brown area anterior to meso-coxa. Scutellum yellowish-brown to brown, apex lighter. Legs yellowish-brown, many specimens with dark brown raised spots or bands on femora and tibiae (see "Taxon Discussion" below). Corium and clavus reddish-brown, veins yellowish-brown; membrane yellowish-brown. Dorsum of abdomen yellowish, reddish, or dark brown; connexival margins and ventral surface yellowish-brown. Pygophore yellowish-brown; some specimens with medial process apically reddish-brown or brown. VESTITURE: Moderately setose. Pubescence of short recumbent and short to long erect setae. Anteocular lobe with short recumbent and erect setae over entire surface, more dense dorsally; postocular lobe with short to moderate recumbent and moderate to long erect setae, erect setae more dense posteriorly. With short to moderate recumbent setae over entire surface, confined to setal tracts on dorsum of anterior pronotal lobe, longer erect setae on lateral surface; scutellum with short recumbent and short to moderate semi-erect and erect setae over surface. Legs with short to long semi-erect to erect setae. Corium and clavus with short, recumbent setae. Abdomen with short recumbent and some short to moderate erect setae over ventral and lateral surfaces. Exposed surface of pygophore with short recumbent and short to long erect setae; short to moderately stiff erect setae on apical half of parameres. STRUCTURE: Head: Cylindrical, L/W = 2.83. Postocular lobe moderately long; in dorsal view anteriorly gradually narrowing, posterior portion constant, slightly narrower. Eye moderately sized; lateral margin only slightly wider than postocular lobe; dorsal and ventral margins removed from surfaces of head. Labium: I: II: III = 1.0: 2.0: 0.5. Basiflagellomere diameter larger than that of pedicel. Thorax: Anterolateral angle bearing small projection; medial longitudinal sulcus evident only on posterior 1/2, deepening anterior to transverse sulcus of pronotum. Posterior pronotal lobe with finely rugulose surface; disc slightly elevated above humeral angle; humeral angle armed, with dentate projection. Scutellum long; apex angulate, not projected. Legs: Slender. Hemelytron: Slightly surpassing apex of abdomen, not more than length of abdominal segment seven; quadrate cell small, elongate; Cu and M of cubital cell subparallel. GENITALIA: (Fig. 49) Pygophore: Ovoid. Medial process cylindrical; slender; long; laterally somewhat compressed; erect; nearly straight; basally without protrusion; apex in posterior view modified, hooklike. Paramere: Cylindrical; moderately long, achieving apex of medial process; directed toward medial process; basally narrower; curved dorsad; apical part enlarged. Phallus: Dorsal phallothecal sclerite shield-shaped; lateral margin recurved dorsad; apical portion of phallothecal sclerite gradually tapering, flat, lateral margin recurved; apex rounded, medially emarginate; posterior margin of foramen broadly concave. Struts attached to dorsal phallothecal sclerite; apically missing. Basal plate arm moderately robust; basally fused; in lateral view basally strongly curved; bridge short; extension of basal plate small, marginally expanded onto arm.

Female: (Fig. 48d, e, f) Similar to male, except for the following. Larger than male, total length 12.89-15.26 mm (mean 14.25 mm, Suppl. material 2). Basiflagellomere subequal in diameter to pedicel. Central 1/3 of mesofemur slightly swollen, pro- and meso-femoral diameters subequal, about 1.3-1.4x diameter of metafemur.


The rather slender body form makes this species easy to separate from other species that occur in the same geographic region. Males can also be recognized by the paramere apically greatly enlarged; the medial process apically curved ventrad, hooklike; the lateral margin of the dorsal phallothecal sclerite recurved. Zelus cervicalis is most similar to Z. renardii and the two share a number putatively synapomorphic characters of structures of male genitalia. The more slender body separates both sexes of Z. cervicalis from Z. renardii . Males of Z. cervicalis also have the apex of medial process not bent as strongly as that in Z. renardii .


South Atlantic and Gulf Coast states of the United States, southeastern Arizona, most of Mexico, Central America and Northern Colombia (Fig. 50). Countries with records: Belize, Colombia, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, USA.

Taxon discussion

Hart (1986) stated that, based on male genitalic characters and pilosity, Z. cervicalis and Z. renardii are closely related species, and we agree with that view. We also corroborate, using a larger specimen sample, the western and eastern parapatric distribution pattern for Z. renardii and Z. cervicalis found by Hart. Based mainly on the coloration of the legs, Hart (1986) delimited two populations of Z. cervicalis , i.e., a South Atlantic and Gulf Coast population and a Mexico-Central America population, the latter also extending to southeastern Arizona and northern Colombia. Most individuals of the South Atlantic and Gulf Coast population have unicolorous legs, or, at most, only a few brownish to reddish spots. Specimens of the Mexico-Central America population have heavily spotted or banded legs. This pattern is also recovered in the current study. However, contrary to Hart's claim that "occasional specimens from either population may occur that do not conform to the normal pattern for that population", we found that all specimens of the Mexico-Central America population have spotted or banded legs. This condition also appears in a small number of specimens in other populations (e.g., UCR_ENT 00016129, UCR_ENT 00039079, UCR_ENT 00042740, UCR_ENT 00042741, UCR_ENT 39522, UCR_ENT 00039519, UCR_ENT 00039531, UCR_ENT 00039525, UCR_ENT 00039561, UCR_ENT 00039560, UCR_ENT 00039559, UCR_ENT 00039557, and more specimens from Texas). We also observed that compared to populations in other US states, specimens from southern Texas tend to have spotted legs, but the density of spots is lower than that in the Mexico-Central America population. By examining previously unstudied Mexican specimens from southern Sonora and northern Sinaloa, we also support Hart's second theory that the Arizona specimens are in continuity with the remainder of the population. The male genitalia are also variable in a number of respects between the two populations (Fig. 49), mainly in the shape of the paramere, the elevation of the lateral margins of the dorsal phallothecal sclerite near the base, and the relative massiveness of the basal plate arms. Hart remarked that the Mexico-Central American specimens show more similarities to the Gulf Coast specimens as one proceeds southward through Central America.

The images of the lectotype of Z. cervicalis are available on the 'Types of Heteroptera ' website of the Swedish Museum of Natural History.