Limnocoris moapensis (La Rivers)

Rodrigues, Higor D. D. & Sites, Robert W., 2019, Revision of Limnocoris (Heteroptera: Nepomorpha: Naucoridae) of North America, Zootaxa 4629 (4), pp. 451-497 : 474-476

Limnocoris moapensis (La Rivers)

( Figs. 1E , 2G , 11 , 14 A–B, 20B)

Usingerina moapensis La Rivers, 1950: 368–373 (original description).

Usingerina moapensis: La Rivers 1971: 77 (catalog); Polhemus & Polhemus 1988: 526 (catalog).

Limnocoris moapensis: Sites & Willig 1994: 810 (new combination); Sites & Nichols 1999: 19–20 (egg description); Nieser & López-Ruf 2001: 319 (catalog).

Diagnosis. This species can be distinguished from all other species of Limnocoris by the condition of the embolium, which is posteriorly projected at its posterolateral angle ( Fig. 11A ). Also, the mesosternal carina has a deep fossa which ranges from rounded to subtriangular ( Figs. 11C ). The hemelytra have the membrane reduced ( Fig. 11A ).

Measurements (n = 5 males / 5 females). Body length 5.73–5.90/ 6.01–6.30, body width 5.10–5.41/ 5.37–5.70, synthlipsis 1.18–1.20/ 1.19–1.25, head length 1.00–1.10/ 1.10–1.15, head width 2.00–2.12/ 2.10–2.20, pronotum length on midline 1.00–1.05/ 1.05–1.10, pronotum width 4.15–4.30/ 4.30–4.60, scutellum length 1.00–1.05/ 1.00– 1.05, scutellum width 2.00–2.20/ 2.10–2.30, hemelytra length 4.10–4.40/ 4.40–4.61.

Supplemental description. Maxillary plate tumescent anteriorly. Antenna not exceeding lateral margin of eye; flagellomeres slender, partially fused, with long setae. Pubescent area of propleuron distinctly extended posteriorly on lateral margin; posterior margin almost straight at mid-length; posteromesal corner near prosternellum deflexed ventrally. Region between mesobasisternum and mesoepisternum without longitudinal row of elongate golden setae. Metasternal carina with fossa teardrop-shaped ( Fig. 11C ), slightly depressed medially ( Figs. 11C, E ); posterior margin slightly excavated in lateral view ( Fig. 11E ). Lateral margin of abdomen with minute serration; posterolateral corners of II–V narrowly rounded to right angled, not spinose; sternum II without row or patch of elongate golden setae ( Fig. 1E ); sterna without generally dispersed elongate setae ( Fig. 2G ). Male: mediotergite VI with accessory genitalic process poorly developed; posterior margin of mediotergite VII shallowly convex; lateral and mesal margins of laterotergite VII subparallel, posterior margin rounded to truncated ( Fig. 14A ); lateral lobe of tergum VIII straight in anterior half of lateral margin; left medial lobe slightly angled posterolaterad at apex, with distal margin rounded; right medial lobe twisted in distal third ( Fig. 14B ). Female: subgenital plate with posterior margin broadly to narrowly rounded; lateral margin without tuft of elongate golden setae ( Fig. 11D ).

Comparative notes. Limnocoris moapensis , despite being easily differentiated from congeners by the embolium condition, shares some characters with L. insularis , L. lutzi , L. nanus n. sp., and L. zacki n. sp.: the pubescent area of the propleuron is distinctly extended posteriorly along the lateral margin, the posterior margin of the propleuron is straight at mid-length, the mesosternum lacks a longitudinal row of elongate golden setae, the abdominal sterna lack generally dispersed elongate setae, and the lateral margin of the female subgenital plate lacks a tuft of elongate setae.

Discussion. The genus Usingerina was described by La Rivers (1950) to accommodate a single species inhabitant of thermal waters, U. moapensis . This species was included in the tribe Usingerinini La Rivers, which was proposed at that time. This tribe was not mentioned again in the literature, not even in the catalog published by the same author ( La Rivers 1971). The status of Usingerina was questioned one year after its publication, when De Carlo (1951) gave the reasons that led him to be skeptical, and later by Štys & Jansson (1988). However, formalization of the synonymy was proposed only by Sites & Willig (1994), who studied the efficacy of morphometric characters in the differentiation of eight species of Naucoridae , and found no support to maintain Usingerina as a distinct genus of Limnocoris .

Distribution. This species is endemic to warm springs in southern Nevada, in the United States ( Fig. 20B ). Field collections at other localities of this region were conducted by RWS and the species was not found, suggesting that it is restricted to the spring-fed river system near Moapa, Clark County, Nevada.

Published records. United States: Nevada ( La Rivers 1950, Sites & Willig 1994).

Type material examined. All specimens brachypterous. HOLOTYPE ♂, UNITED STATES, Nevada, Warm Sprs., Clark Co., 26–27.XII.1948, LaR, Type No. 7179 ( CAS). PARATYPES: same data as holotype (13♂, 13♀, including allotype, CAS; 1♀, EMEC) .

Additional material examined. All specimens brachypterous. UNITED STATES, Nevada, same data as holotype (2♂, EMEC) ; Coburn’s Warm Springs nr. Moapa , Clark Co., 28.Jan.1956, Menke & Stange (3♂, 2♀, EMEC) ; Clark Co., Warm Springs, N. of Glendale , 01.Sep.1984, C. Riley Nelson (2♂, 2♀, BYUC) ; Clark Co., Warm Springs, N. of Glendale , 28.Sep.1984, M.F. Whiting (13♂, 7♀, BYUC) ; Clark Co., Warm Springs , 29.Mar.1985, Baumann (6♂, 5♀, BYUC) ; same data, except 11.IX.1987, B. Sargent (2♂, 1♀, BYUC) ; same data, except 11.IX.1987, D. Beazer (1♂, BYUC) ; same data, except Gunther (2♂, BYUC) ; same data, except 30.IX.1987 (2♂, BYUC) ; same data, except Moapa R., 15.May.1987, Baumann-Hardy (1♂, 1♀, BYUC) ; Clark Co., Moapa Warm Spring , 8 November 1998, coll R.W. Sites, gravel stream bed (5♂, 5♀, MZUSP) ; Clark Co., Muddy River, Warm Springs , 36°44’N / 114°42’W, 18.XII.1995, Baumann & Huntsman (7♂, 6♀, BYUC) .

Figures

FIGURE 1. Structures of Limnocoris. (A–D) Propleuron, white arrows indicate posterior end of pubescent area, yellow arrows indicate mid-lateral region of posterior margin, (A) L. zacki n. sp., (B) L. inornatus, (C) L. virescens, (D) L. chaetocarinatus n. sp. (E–H) Part of abdominal segments, showing pubescence patterns of sternum II (circled), (E) L. moapensis, (F) L. submontandoni, (G) L. nanus n. sp., and (H) L. stali. pa = pubescent area, pra = pruinose area.

FIGURE 2. (A–B) Lateral view of meso- and metasternal carinae, (A) L. pygmaeus, white arrow indicates anterior projection, black arrow indicates excavation posterior to fossa, (B) L. zacki n. sp., black arrow indicates median projection of mesosternal carina. (C–D) Ventral view of meso- and metasternal carinae, (C) L. inornatus, white arrow indicates row of longitudinal golden setae between mesobasisternum and mesoepisternum, (D) L. zacki n. sp., white arrow indicates fossa partially open anteriorly, dotted lines indicate anterior and posterior limits of fossa. (E–F) Ventral view of abdominal segments III–V, (E) L. virescens, black arrows indicate posterolateral corners, (F) L. panamensis. (G–H) Ventral view of female abdominal segments IV–IX, (G) L. moapensis, sgp = subgenital plate, (H) L. major n. sp., white arrows indicate elongate golden setae, gs= posterolateral elongate golden setae on lateral margin of subgenital plate.

FIGURE 11. Limnocoris moapensis (La Rivers). (A) Dorsal habitus and (B) ventral habitus of female, hindwing brachypterous (UMC), (C) ventral view of head and part of thorax, (D) terminal abdominal sterna of female, (E) lateral view of meso- and metasternal carinae. Size bar = 1.00 mm and applies only to Figs. A–B.

FIGURE 14. Structures of male terminalia. (A, C, E) 6th and 7th abdominal terga, (B, D, F) 8th abdominal tergum. (A–B) Limnocoris moapensis, (C–D) L. nanus n. sp., and (E–F) L. panamensis.

FIGURE 20. (A–B) Distribution records for species of Limnocoris in North America.