Limnocoris pygmaeus La Rivers, 1971

Rodrigues, Higor D. D. & Sites, Robert W., 2019, Revision of Limnocoris (Heteroptera: Nepomorpha: Naucoridae) of North America, Zootaxa 4629 (4), pp. 451-497 : 483-485

Limnocoris pygmaeus La Rivers

( Figs. 2A , 15 , 19 A–B, 20A)

Limnocoris pygmaeus La Rivers, 1956: 92–94 (original description).

Limnocoris solenoides La Rivers, 1970: 5–6 (original description) (new synonym).

Limnocoris pygmaeus: La Rivers 1971: 76 (catalog); Nieser & López-Ruf 2001: 319 (catalog).

Diagnosis. The distal margin of the labrum is distinctly acuminate ( Fig. 15D ). The mesosternal carina has the lateral margins of the fossa touching each other, leaving a small posterior opening ( Fig. 15D ). The dorsal surface of the body is usually yellow to light brown, and the hemelytral membrane has a pale spot medially ( Figs. 15A, C ).

Measurements (n = 5 males / 5 females). Body length 5.50–6.80/ 5.90–7.20, body width 4.00–4.90/ 4.20–4.93, synthlipsis 1.15–1.23/ 1.20–1.27, head length 0.95–1.18/ 1.00–1.17, head width 1.90–2.40/ 2.00–2.40, pronotum length on midline 1.03–1.40/ 1.20–1.45, pronotum width 3.41–4.30/ 3.62–4.30, scutellum length 0.82–1.10/ 1.02– 1.20, scutellum width 1.70–2.40/ 1.95–2.40, hemelytra length 4.10–5.10/ 4.43–5.25.

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 (as in Fig. 1B ); posterior margin of propleuron convex at mid-length; posteromesal corner near prosternellum deflexed ventrally. Region between mesobasisternum and mesoepisternum with longitudinal row of elongate golden setae ( Fig. 15D ). Metasternal carina well developed, fossa rounded to teardrop-shaped ( Fig. 15D ), slightly depressed medially; posterior margin excavated in lateral view. Lateral margin of abdomen with minute serration; posterolateral corners of II–V narrowly rounded to right angled, not spinose; sterna with elongate golden setae generally dispersed, concentrated at midline of segments III–V; sternum II with sinuous row of golden setae. Male: mediotergite VI with accessory genitalic process poorly developed; posterior margin of mediotergite VII ranging from convex to sinuous, forming two inconspicuous lobes medially; laterotergite VII with mesal margin convex ( Fig. 19A ); lateral lobe of tergum VIII with lateral margin straight in anterior half; left medial lobe with small distolateral production, with distal margin rounded; right medial lobe slightly twisted in distal third ( Fig. 19B ). Female: lateral margins of subgenital plate with tuft of elongate setae at mid-length, posterior margin ranging from convex to narrowly rounded; laterosternite VII with posterolateral corner produced posteriorly ( Fig. 15E ).

Comparative notes. This species is morphologically similar to L. inornatus , sharing the general morphology and pubescence of the body. In specimens of L. pygmaeus , the dorsal coloration of the body is light brown to yellowish, and the hemelytral membrane has a large pale central spot, whereas in L. inornatus the body color is usually medium brown to dark brown, and the hemelytral membrane is mottled with light brown, but not as a single medial spot.

Discussion. Examination of paratypes of L. pygmaeus and L. solenoides revealed that both species are morphologically very similar and identical in features that are generally used to discriminate among species of Limnocoris . In the original description of L. solenoides, La Rivers (1970) differentiated it from L. pygmaeus only by having a longer body, a more “developed” color pattern and by the claval suture more prominent. We consider these differences to be intraspecific variation and propose L. solenoides to be a junior synonym of L. pygmaeus . In addition, three female paratypes of the type series of L. laucki were misidentified and are L. pygmaeus ; this was confirmed after examination of the holotype of L. laucki , which differs substantially from L. pygmaeus . However, L. laucki is here proposed as a junior synonym of L. signoreti (see Discussion in L. signoreti ).

Distribution. This species is known only from Mexico. The records are concentrated in the western part of the country ( Fig. 20A ).

Published records. Mexico: Guerrero ( La Rivers 1956).

Type material examined. All specimens macropterous. PARATYPES of L. pygmaeus : MEXICO, Guerrero, Kil. 438, South of Mex. City, 11.I.1936, H.D. Thomas (3♂, 2♀, CAS; 1♀, USNM). PARATYPES of L. solenoides : MEXICO, Oaxaca, 18 mi. NW El Camaron, 20.VIII.1959, A.E. Menke collector (1♂, 2♀, CAS). PARATYPES of L. laucki : MEXICO, Nayarit, Ahuacatlán , 12.Aug.1957, D. Lauck (2♀, CAS; 1♀, USNM) .

Additional material examined. All specimens macropterous. MEXICO, Guerrero, Acahuizotla, 27.VI.1983, M. García (1♂, USNM). Jalisco, 6.6 Km SE Villa Purificacion, Puente El Amborin , 08.I.2005, William D. Shepard leg (11♂, 25♀, EMEC) ; 3.4 Km NW El Tuito, 15.I.2005, 1900’, Rio Tuito , William D. Shepard leg (1♂, EMEC) ; SE of Chamela, 06.I.2005, 180’, Rio Cuitzmala , William D. Shepard leg (9♂, 11♀, EMEC) ; Hwy 200, Km 84.5, 06.I.2005, 100’, Rio San Nicolas , William D. Shepard leg (1♂, 2♀, EMEC) ; El Rincon, CL-1231, 27.XI.1968, J.T. Polhemus (1♀, USNM) ; Rio Tomatlan , 300’, CL-736, 09.VI.1975, J.T. Polhemus (2♂, USNM) ; N. Campo Acosta, CL-737, Rio San Nicolas , 09.VI.1975, J.T. Polhemus (1♂, 3♀, USNM) ; Rio Tomatlán , 300’, CL-736, 09.VI.1975, J.T. Polhemus (2♀, USNM) ; El Tuito, 17.III.1975, H. Brailovsky (1♂, USNM) ; Río Cuitzmala, 2.5 Km North of Emiliano Zapata , 06.I.2005, C.B. Barr (2♂, 2♀, UMC) . Nayarit, Las Sabinas, Mpio de Nayar , 11.IV.1991, E. Barrera & J. Leon (3♂, 1♀, UMC) ; Rio Santiago, Colorado de la Mora, Arroyo San Pobleño , 20.V.1991, R. Barba & E. Barrera (1♀, UMC) . Oaxaca, 23 Km carr-, Pochutla , 08.II.1982, A. Ibarra (1♀, USNM) ; same data, except 07.II.1982 (1♂, USNM) ; San Cristobal , 17.VI.1984, M. García (1♂, 1♀, USNM) ; same data, except R. Mendoza (1♀, USNM) ; Candelaria Loxita , Rio San Juan, N 15º55.583’, W 96º29.225’, 427 m, 2 April 2015, Sites, Reynoso- Velasco, Shepard, Barr, rocks, gravel L-1904 (11♂, 19♀, UMC) ; Candelaria Loxita, Rio San Juan at Puente San Juan, N 15º55.541’, W 96º29.400’, 410 m, 2 April 2015, Sites, Reynoso-Velasco, gravel riffles L-1905 (4♂, 2♀, UMC; 1♀, MZUSP) ; Mpio. San Gabriel Mixtepec, San Gabriel Mixtepec , Rio Rana, N 16º6.107’, W 97º3.880’, 696 m, 2 April 2015, Sites, Reynoso-Velasco, Shepard, Barr, rocks & gravel, L-1906 (12♂, 6♀, UMC; 1♂, MZUSP) ; Rio Las Arenas , N16º19.953’, W98º0.928’, 54 m, 3 April 2015, Sites & Reynoso-Velasco, sand & rocks, L-1907 (6♂, 22♀, UMC) . Sinaloa, Villa Union , CL- 1022, 21.April.1964, J.T. Polhemus & M.S. Polhemus (5♂, 6♀, USNM) ; Mazatlán , 25–26.V.1934, H.E. Hinton (1♂, 1♀, USNM) ; Villa Union , 10’, CL-718, 06.VI.1975, J.T. Polhemus (7♂, 2♀, USNM; 1♂, UMC) . Sonora, 9 mi. E Sabino , 1500’, CL-727, 05.VI.1973, J.T. Polhemus (1♀, USNM) .

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 15. Limnocoris pygmaeus La Rivers. (A) Dorsal habitus and (B) ventral habitus of female paratype, hindwing macropterous (CAS), (C) dorsal habitus of male, hindwing macropterous (UMC), (D) ventral view of part of head and thorax, (E) terminal abdominal sterna of female, and (F) 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.