Nigrotomocoris Henry and Menard, 2020

Henry, Thomas J. & Menard, Katrina L., 2020, Revision and Phylogeny of the Eccritotarsine Plant Bug Genus Caulotops Bergroth, with Descriptions of Four New Genera and 14 New Species (Hemiptera Heteroptera: Miridae: Bryocorinae) Associated with Agave (Agavoideae Asparagaceae) and Related Plant Genera, Zootaxa 4772 (2), pp. 201-252 : 232-233

Nigrotomocoris Henry and Menard , new genus

urn:lsid:zoobank.org:act:C70C4502-C6EE-46FB-B597-F2AE9BF8F8AE

Type Species: Caulotops nigrus Carvalho, 1984 . By present designation.

INCLUDED SPECIES. N. keltoni , n. sp.; N. longirostris , n. sp.; N. nigrus (Carvalho) , n. comb.; and N. tibiopallidus (Carvalho) , n. comb.

DIAGNOSIS. Distinguished by the often dorsoventrally flattened body, overall black color, the stout apically blunt tubercle on the genital capsule, the small L-shaped left paramere, the apically spatulate right paramere, and the presence of a plate rather than a lateral arm in the female genitalia.

DESCRIPTION. Macropterous, weakly oval. Length from apex of head to cuneal fracture 2.08–2.48 mm; length from apex of head to apex of membrane 3.00– 3.44 mm; widest width across hemelytra 1.38–1.88 mm. COLOR- ATION. Head: Black, posterior margin of vertex sometimes with a broad pale or whitish-yellow transverse band extending across basal margin between eyes; eyes purplish to brownish red; first antennal segment dark brown to black, remaining segments yellowish brown or black; labium dark brown to black. Thorax: Pronotum, mesoscutum, scutellum black; coxae and femora dark brown to black, tibiae pale or dark brown to black, tarsomeres yellowish brown to dark brown. Hemelytron: Dark brown to black, sometimes with a slight bluish sheen; membrane dark smoky brown with single areole dark brown to black. Abdomen: fuscous to black, genital tubercle dark brown to black. SURFACE AND VESTITURE. Head: Impunctate; surface dull to weakly shining, with short white sericeous setae; antennal segments covered with short, dense, simple setae. Thorax: Pronotum, mesoscutum, and scutellum with short, white, simple and sericeous setae; posterior half of pronotum to calli punctate; calli, anterior margin, head, and scutellum impunctate. Hemelytron: Impunctate, with simple, short, white setae, including veins of membrane. Abdomen: Covered with sparse simple setae. STRUCTURE. Head: Head wider than height, width across eyes equal to or narrower than posterior width of pronotum, frons and vertex transversely convex, with a shallow median groove and a transverse impression across base, in combination, sometimes forming an indistinct inverted T-shaped depression; clypeus visible in dorsal view, greater than one half total height of head below eyes; posterior margin of eyes contiguous with and wrapping around head and anterior angles of pronotum, interocular distance greater than twice width of one eye; lengths of antennal segments I and III and interocular width subequal, filamentous segments III and IV half as long as segments I and II. Thorax: Pronotum: Anterior margin before calli flat, lateral margins straight to weakly sinuate; calli prominent, separated by a deep median impression and bordered posterolaterally by smaller but distinct impression; posterior margin straight to weakly concave; mesoscutum exposed; scutellum equilateral, with lateral margins forming a raised, V-shaped ridge; metathoracic scent gland auricle tongue-shaped, with a narrow, laterally oriented channel, occupying less than one-fourth total area of metasternum; legs relatively short, pretarsus typical of eccritotarsines, with large fleshy pulvilli. Hemelytron: Lateral margins weakly convex, wide at base; basal width of cuneus subequal to length; large areole length greater than half the length of the membrane. Abdomen: Relatively round, somewhat flattened, genital capsule with a large, oval aperture; left dorsolateral margin with a stout, blunt tubercle, forming a “hook” to hold right paramere in situ.

Male genitalia: Endosoma ( Fig. 104 ) with an elongate sclerotized ductus seminis enclosed in membrane; phallotheca thin and simple. Left paramere ( Figs. 105, 107, 109, 111 ) L- or scythe-shaped. Right paramere ( Figs. 106, 108, 110, 112 ) elongate, weakly C-shaped, with the apex broadly spatulate.

Female: Similar to male in size, shape, and coloration.

Female genitalia: Vestibulum ( Fig. 140 ) with two enlarged plates protruding anteriorly into abdomen and interlocking with each other, invaginated in on themselves; lateral plate on left side of vestibulum with two parallel serrated plates facing each other ( Fig. 140 ), dorsal to another rounded flat plate, and adjacent to two C-shaped rounded plates on the left side; dorsal surface of ovipositor ( Fig. 144 ) with fine serrations along margin, more minute serrations on inner valvifers; dorsal sac with visible, well-sclerotized ring structures; posterior wall membranous, with base of ovipositor dorsally projecting to touch posterior wall.

ETYMOLOGY. The name Nigrotomocoris is derived from a combination of Latin “ nigra,” meaning black, “toma” from Halticotoma to indicate the overall general resemblance with this genus, and “coris,” meaning bug. The gender is masculine.

DISCUSSION. Synapomorphies for this lineage in our analysis include the large, apically blunt tubercle ( Figs. 131–134 ) [except for N. keltoni ] on the upper left side of the male genital capsule and completely black head, thorax, and coxae. This genus also shares several synapomorphies with Schaffnerocoris , including the T-shaped invagination on the vertex and the presence of relatively dense sericeous setae on the head.

The female genitalia in this genus are complex, with opposing deeply toothed plates ( Fig. 140 ) on the right side of the vestibulum as in Schaffnerocoris . Nigrotomocoris , however, does not have a pronounced lateral arm, and instead seems to have a plate similar to the arm in the other taxa of this study. To better understand this system and determine whether this plate is homologous to the lateral arm, a more in-depth study of this mating system needs to be undertaken, which is beyond the scope of this paper. In this study, we assume it is a separate structure.

Specimens of N. keltoni , N. longirostris and N. nigrus are more dorsoventrally compressed than N. tibiopallidus . Nevertheless, the shared shape of the eyes that wrap around the anterior angles of the pronotum, the uniformly black bodies and coxae, and the elongate, apically spatulate right paramere link these four species together.

Figures

FIGURES 104–112. Male genitalia of Nigrotomocoris spp. N. keltoni, n. sp.: 104, endosoma. 105, left paramere. 106, right paramere. N. longirosris, n. sp.: 107, left paramere. 108, right paramere. N. nigrus: 109, left paramere. 110, right paramere. N. tibiopallidus: 111, left paramere. 112, right paramere.

FIGURES 138–141. Female vestibula and ovipositors. 138, Agaveocoris agavis (left arrow pointing to ventral labiate plates; right arrow pointing to lateral arm). 139, Laterospinocoris cyaneipennis (arrow pointing to ventral labiate plates; right arrow pointing to lateral arm). 140, Nigrotomocoris nigrus (arrow pointing to ventral labiate plates and opposing deeply tooth structures; right arrow pointing to lateral arm). 141, Schaffnerocoris pallipes, n. sp. (arrow point to ventral labiate plates and opposing deeply toothed structures; right arrow pointing to lateral arm).

FIGURES 142–145. Female ovipositors, left lateral view (top: first gonopophysis; bottom: second gonopopysis). 142, A. agavis. 143, L. cyaneipennis. 144, N. nigrus. 145, S. pallipes, n. sp.

FIGURES 129–137. Male genital tubercles of Laterospinocoris, Nigrotomocoris, and Schaffnerocoris spp. 129, L. cyaneipennis. 130, L. mexicanus, n. sp. 131, N. keltoni, n. sp. 132, N. longirostris, n. sp. 133, N. nigrus. 134, N. tibiopallidus. 135, S. fuscotibialis, n. sp. 136, S. pallipes, n. sp. 137, S. similis, n. sp.