Limnocoris signoreti Montandon, 1898

Rodrigues, Higor D. D. & Sites, Robert W., 2019, Revision of Limnocoris (Heteroptera: Nepomorpha: Naucoridae) of North America, Zootaxa 4629 (4), pp. 451-497 : 485-487

Limnocoris signoreti Montandon

( Figs. 16 , 19 C–D, 20A)

Limnocoris signoreti Montandon, 1897: 5 (original description).

Limnocoris laucki La Rivers, 1970: 1–3 (original description) (new synonym).

Limnocoris brailovskyi La Rivers, 1976: 10–11 (original description) (new synonym).

Limnocoris stangei La Rivers, 1976: 13–14 (original description) (new synonym).

Limnocoris signoreti: Montandon 1898: 416 (key); Torre-Bueno 1906: 52 (catalog); Kirkaldy & Torre-Bueno 1909: 183 (catalog); La Rivers 1971: 76 (catalog); Nieser & López-Ruf 2001: 319 (catalog).

Lectotype designation. In the original description, Montandon (1897) mentioned three specimens in the type series of L. signoreti , but did not designate a holotype. We examined these three specimens, each deposited in a different museum: BMNH (1♂), MNHN (1♂), and NHMW (1♀). The specimens deposited in the BMNH and NHMW have in the locality label only the name of the country: Mexico. The specimen from MNHN has no locality information, a fact already mentioned in the original description. We herein designate the female specimen in the NHMW as the lectotype in order to fix the identity of this species. Thus, the two males from BMNH and MNHN are designated as paralectotypes.

Diagnosis. This species can be distinguished from all other North American species of Limnocoris by the morphology of the mesosternal carina. The fossa is elliptical or oval and partially closed along the midline and posterior region, leaving the fossa open anteriorly and sometimes posteriorly ( Figs. 16 D–E).

Measurements (n = 5 males / 5 females). Body length 7.20–8.24/ 8.16–9.00, body width 5.60–6.12/ 5.82–6.40, synthlipsis 1.45–1.46/ 1.40–1.60, head length 1.25–1.30/ 1.30–1.40, head width 2.60–2.80/ 2.70–2.90, pronotum length on midline 1.50–1.80/ 1.55–1.72, pronotum width 4.88–5.45/ 5.00–5.60, scutellum length 1.30–1.40/ 1.30– 1.52, scutellum width 2.70–2.90/ 2.65–3.20, hemelytra length 5.35–6.20/ 6.10–6.80.

Supplemental description. Maxillary plate tumescent anteriorly. Antenna not exceeding lateral margin of eye; pedicel quadrate; flagellomeres slender, not partially fused, with long setae. Pubescent area of propleuron distinctly extended posteriorly along lateral margin; posterior margin of propleuron convex at mid-length; posteromesal cor- ner near prosternellum deflexed ventrally. Region between mesobasisternum and mesoepisternum with longitudinal row of elongate golden setae ( Figs. 16 D–E). Metasternal carina with fossa oval ( Fig. 16D ) to teardrop-shaped ( Fig. 16E ), slightly depressed medially; posterior region excavated in lateral view ( Figs. 16H ). Lateral margin of abdomen with minute serration; posterolateral corners of II–V narrowly rounded to right angled, not spinose; sternum II with sinuous row of golden setae; sterna with elongate golden setae generally dispersed, concentrated at midline of segments III–V. Male: mediotergite VI with accessory genitalic process poorly developed; posterior margin of mediotergite VII with two central lobes and two lateral inconspicuous lobes; mesal margin of laterotergite VII shallowly convex ( Fig. 19C ); lateral lobe of tergum VIII with lateral margin shallowly concave in anterior half; left medial lobe angled laterally at apex, distal margin truncate; right medial lobe twisted in distal third ( Fig. 19D ). Female: lateral margins of subgenital plate converging posteriorly in apical two thirds to narrowly rounded apex, with tuft of elongate setae at mid-length; laterosternites VII converging posteriorly ( Fig. 16G ).

Comparative notes. Limnocoris signoreti has the mesosternal carina and pubescence pattern of the body similar to that of L. ovatulus Montandon , a species that occurs in the Andes Mountains in Peru, Bolivia, and Argentina. However, in L. signoreti the posterolateral corners of III–V are rounded to right angled, whereas in L. ovatulus these corners are distinctly produced. Because we found no variation in this character within each of these species, in addition to the widely separated geographical distributions, we consider L. ovatulus and L. signoreti each to be a distinct species.

Discussion. We examined type material of L. signoreti , L. brailovskyi , L. laucki , and L. stangei . Examination of many specimens revealed this species to have substantial intraspecific variation. More specifically, specimens range from a yellow-orange to a dark brown color, the distal margin of the labrum can be convex to slightly acuminate, and the lateral margin of the embolium may be angled or rounded in the posterior two thirds. In some specimens the anterior projection of the mesosternal carina was underdeveloped. La Rivers (1960, 1976) described L. laucki , L. brailovskyi , and L. stangei based on these variable characters, which can differ within the same population. As such, we propose L. brailovskyi , L. laucki , and L. stangei to be junior synonyms of L. signoreti .

Distribution. This species is known only from Mexico, with records ranging from Nayarit in the west coast to the south of the country ( Fig. 20A ).

Published records. Mexico: Jalisco and Nayarit ( Montandon 1897; La Rivers 1970, 1976).

Type material examined. All specimens macropterous. LECTOTYPE ♀, MEXICO, Coll. Signoret ( NHMW) . PARALECTOTYPES: same data as lectotype (1♂, BMNH) ; without locality data, Coll. G. Fallou 259–95 (1♂, MNHN) . HOLOTYPE of L. brailovskyi , MEXICO, Jalisco, Tuito , 17.March.1975, Harry Brailovsky (♂, UNAM) . PARATYPES of L. brailovskyi : same data as holotype (1♂, CAS) ; MEXICO, Jalisco, Guadalajara , 01. VII.3 (?) (1♂, CAS) . HOLOTYPE of L. laucki , MEXICO, Nayarit, Ahuacatlan , 12.Aug.1957, D. Lauck (♀, CAS) . PARA- TYPES of L. laucki : same data as holotype (22♂, including ‘ allotype,’ 21♀, CAS; 1♂, 1♀, USNM) . PARATYPES of L. stangei : MEXICO, Nayarit, 23 mi SE Tepic , 26.VIII.1959, A.S. Menke & L.A. Stange collectors (1♂, 1♀, CAS) .

Additional material examined. All specimens macropterous. MEXICO, Chiapas, 1 mi SW of Ixhuatan, CL-1098, 05.May.1964, J.T. & M.S. Polhemus (2♂, 2♀, USNM). Jalisco, Estacion Biologica Chamela-Jalisco, R. Tomatlan, 19.III.75, H. Brailovsky (1♂, USNM) ; Guadalajara , J.R. de La Torre Bueno Collection (2♂, 2♀, UMC) ; Guadalaraja , 1. VII.3 (1♂, USNM; 2♂, EMEC) . Mexico, Tejupilco, Temescaltepec , 15.VI.1933, H.E. Hinton & R.L. Usinger collectors (4♂, 5♀, EMEC) ; same data, except 18.VI.1933 (2♂, 1♀, EMEC) ; same data, except 19.VI.1933 (1♀, EMEC) ; same data, except 20.VI.1933 (1♀, USNM; 1♀, EMEC) ; same data, except 27.VI.1933 (1♀, EMEC) ; same data, except VII.1934 (2♀, EMEC) ; Paso de Vigas, Arroyo Paso de Vigas , 05 April 2015, L-1909, algae & gravel in pools, 18°53.548’N / 100°13.963’W, Reynoso-Velasco, Sites & Shepard (1♀, MZUSP) . Oaxaca, Mpio Valle Nacional San Mateo Yetla, 13.X.1990, E. Barrera, E. Ramirez & A. Cadena (2♂, 1♀, UMC; 1♀, MZUSP) ; San Mateo Yetla , 20.XI.1990, E. Barrera & A. Cadena (1♀, UMC) . Veracruz, Zongolica , 11.VIII.74, J. Bueno (1♀, USNM) .

Figures

FIGURE 16. Limnocoris signoreti Montandon. (A) Dorsal habitus and (B) ventral habitus of male, hindwing macropterous (UMC), (C) dorsal habitus of female holotype of L. laucki n. syn., hindwing macropterous (CAS), (D–E) ventral view of part of thorax, (F) head and part of prosternum, (G) terminal abdominal sterna of female, and (H) lateral view of meso- and metasternal carinae. Size bar = 1.00 mm and applies only to Figs. A–C.

FIGURE 19. Structures of male terminalia. (A, C, E, G) 6th and 7th abdominal terga, (B, D, F, H) 8th abdominal tergum. (A–B) Limnocoris pygmaeus, (C–D) L. signoreti, (E–F) L. virescens, and (G–H) L. zacki n. sp.

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