Limnocoris rodriguesi Reynoso 2020, NEW SPECIES
Creators: name: Reynoso-Velasco, Daniel
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Naucoridae
Limnocoris
Limnocoris rodriguesi

description: Limnocoris rodriguesi Reynoso NEW SPECIES
(Figs. 6–8)
Limnocoris signoreti: Rodrigues & Sites, 2019: 487 (misidentification, in part).
Description. Male. HOLOTYPE, length 8.46; maximum width 6.05. Paratypes (n = 3), length 8.30–8.72 (mean = 8.44); maximum width 6.06–6.39 (mean = 6.20). General shape rounded to oval; widest across midsection of embolia. Overall dorsal coloration yellowish-brown to light-brown, mottled on head, pronotum, and corium; hemelytral membrane dark-brown, light-brown mottled (Fig. 6A). Dorsal surface of pronotum and hemelytra (except membrane) finely granulated. Ventral coloration yellowish-brown to dark-brown (Fig. 6B).
Head. Head length 1.48; maximum width 2.72. Mostly yellowish-brown with brown marks along medial line and posteriorly. Eyes divergent anteriorly; synthlipsis 1.44; thin band of cuticle along anterolateral margin of eye; eyes not raised above level of vertex or pronotum. Anterior margin between eyes shallowly convex medially, extending anteriorly in front of eyes 13% of head length; posterior margin between eyes not extending posteriorly. Maxillary plate tumescent anteriorly. Labrum pentagonal, width 1.1× length, bluntly pointed, apically pubescent. Labium with three visible yellowish segments, darkening distally, extending 0.33 beyond labrum not including extruded stylets. Antenna 4-segmented, antennal proportions 6:14:13:9, length 0.63, extending to lateral margin of eye; pedicel subquadrate; flagellomeres slender, with long setae, nor partially fused.
Thorax. Pronotum ground color yellowish-brown, brown marking on rectangular area behind eyes; slight transverse sulcus marking anterior border of light brown transverse band in posterior 1/3; anterior margin almost straight between eyes; lateral margins convergent anteriorly, evenly convex, posterior margin convex, shallowly concave medially; posterolateral corners rounded (Fig. 6A); greatest width 2.9× length at midline; length at midline 1.76; maximum width at posterolateral corners 5.14. Prothorax ventrally mostly yellowish-brown, dark-brown medially and posteriorly. Propleura with pubescent area extending posteriorly on lateral margin; elongate golden setae near proacetabulum; posterior margin convex at mid-length (Fig. 6B); posteromesal corner near prosternellum slightly deflexed ventrally, tuberculate. Median carina of probasisternum with a bifid tubercle anteriorly in lateral view.
Scutellum triangular, not punctate, and not tuberculate; brown, two reniform to ovate dark-brown marks medially; width 2.1× length, width 3.04, length 1.40. Hemelytra length 6.0 (chord measurement), tuberculate, lightbrown, with brown markings throughout, mostly on corium. Embolium length 2.68, greatest width 0.78; lateral margin convex, yellowish-brown in anterior half, brown posteriorly. Clavus light-brown, length 4.5× width, length 3.28, width 0.72; claval commissure dark-brown, length 0.60. Membrane dark-brown and light-brown mottled (Fig. 6A). Hindwings extending to posterior margin of tergum V. Region between mesobasisternum and mesoepisternum with longitudinal row of elongate golden setae. Mesosternal carina arrowhead-shaped in posterior half (Figs. 6B, C); anterior half with anterior projection low (Fig. 6D) and median ridge between anterior projection and fossa straight (Fig. 6C). Metasternal carina with fossa ellipsoidal, slightly depressed medially; posterior margin excavated in lateral view (Fig. 6D).
Legs. All legs segments brown, except dark-brown apical part of tarsomere 3 of middle and hind legs (Fig. 6B). Procoxa with cluster of stout, light-brown anteromedial spines. Profemur anterior margin with dense pad of setae without associated spines; posterior margin with row of long golden setae medially. Protibia and tarsus with occlusal inner surface flattened; tarsus one-segmented, immovable; pretarsal claw single, minute, triangular. Meso- and metacoxae partially recessed into thorax. Meso- and metafemora with row of short, slender, brown spines on anterior margin. Meso- and metatibiae with ventrolateral, ventromedial, dorsolateral, and dorsomedial rows of stout brown spines; meso- and metatibiae with two transverse combs of tightly-arranged spines distally, one on ventral and another on dorsal margins. Meso- and metatibiae and metatarsus with long, yellow swimming hairs, hairs profuse on metatibia and –tarsus. Meso- and metapretarsi with paired claws slender, gently curved, with minute basal tooth. Leg measurements as follows: fore leg, femur 2.15, tibia 1.42, tarsus 0.50; middle leg, femur 2.15, tibia 1.50, tarsomeres 1–3, 0.18, 0.30, 0.51; hind leg, femur 2.92, tibia 2.76, tarsomeres 1–3, 0.16, 0.67, 0.70.
Abdomen. Dorsally with lateral margins of terga III–VIII exposed; terga III–V dark-brown anteriorly, yellowish-brown posteriorly (Fig. 6A); marginal row of short yellow setae, and group of trichobothria near posterolateral corners. Lateral margin of abdominal segments II–VI with minute serration. Posterolateral corners of II–V right angled, not spinose. Sterna predominantly dark-brown, light-brown on lateral margins of III–VI, with scattered elongate golden setae; sternum II with sinuous patch of elongate golden setae (Fig. 6B). Mediotergite VI with ac- cessory genitalic process developed (Fig. 6E). Mediotergite VII posterior margin with rounded, inconspicuous posterolateral corners and two rounded central lobes; lateral lobe with lateral margins parallel, posterior margin broadly rounded (Fig. 6E). Lateral lobe of tergum VIII with lateral margin shallowly concave in anterior half, convex distally; left medial lobe angled laterally at apex, pointed apically, with distal margin almost truncate; right medial lobe twisted in distal third (Fig. 6F); mediosternite VIII with central notch on posterior margin (Fig. 6G).
Female. Paratypes (n = 2), length 8.55–8.96 (mean = 8.76); maximum width 6.14–6.23 (mean = 6.18). Similar to male in general structure and coloration. Otherwise hindwings extending to posterior margin of tergum VI. Abdominal tergum VI symmetrical. Subgenital plate width 0.97× length; length at midline 1.17; maximum width 1.14; lateral margins converging in apical half to narrowly rounded apex, with tuft of elongate golden setae at mid-length (Fig. 6H).
Diagnostic features. Limnocoris rodriguesi is, together with L. signoreti, the largest species known to occur in Mexico (length ≈ 9.0 mm). Specimens of L. rodriguesi can be identified by a set of characters that include: the distal margin of the labrum bluntly pointed, pubescent area of the propleuron distinctly extended posteriorly along the lateral margin, the posterior margin of the propleuron convex at mid-length (Fig. 6B), and the posterior half of the mesosternal carina in ventral view in the shape of an arrowhead and open anteriorly (Figs. 6B, C). Additionally, the mesosternal carina has a low anterior projection (Fig. 6D). Furthermore, the males present the accessory genitalic process developed (Fig. 6E) and abdominal mediosternite VIII has a medial notch on the posterior margin (Fig. 6G). The females present the lateral margins of the subgenital plate slightly convex in the apical half and converging to a narrowly rounded apex (Fig. 6H).
Comparative notes. This new species is morphological similar to L. signoreti, including body size and shape. However, the main feature to distinguish specimens of L. rodriguesi is the characteristic mesosternal carina, which is arrowhead-shaped and open anteriorly (elliptical or oval and open anteriorly and sometimes posteriorly in L. signoreti). Also, the lateral margins of the female subgenital plate are slightly convex in the apical half, converging posteriorly to a narrowly rounded apex (straight in apical two thirds and converging to a narrowly rounded apex in L. signoreti).
Distribution. This species is known to occur only in the southern Mexican state of Oaxaca (Fig. 7). The localities where Limnocoris rodriguesi was collected are in the Sierra Madre del Sur biogeographic province; more specifically, in the westernmost district of Tierras Altas Oaxaqueñas. Rodrigues & Sites (2019) reported five specimens (2♂, 2♀ UMC; 1♀ MZUSP) of L. signoreti from San Mateo Yetla in norther Oaxaca. A closer examination of the specimens revealed that four of them belong to L. rodriguesi and only one male (UMC) belongs to L. signoreti. Limnocoris rodriguesi was collected syntopically with L. pygmaeus at Río Rana (L-1906) and La Cuchara (L-1396) and with L. signoreti at San Mateo Yetla (13-X-1990). Additionally, this species was collected syntopically with several species of Naucoridae in the genus Ambrysus, including: A. baeus Polhemus & Polhemus, A. henryi Reynoso & Sites, A. schuhi Reynoso & Sites, A. sitesi Reynoso, and A. spicatus La Rivers at Río Rana (L-1906); and with A. pygmaeus La Rivers at La Cuchara (L-1396), and with A. pygmaeus and A. spicatus at Putla de Guerrero (L-1397). Furthermore, this species was also collected syntopically with the saucer bug and rock-clinging species Cataractocoris macrocephalus (Montandon) at the type locality. The state of Oaxaca is known for its high biodiversity, including that of insects. The stream at the type locality is the habitat of at least seven species of Naucoridae in three genera (Ambrysus, Cataractocoris Usinger, Limnocoris), including the three recently described species Ambrysus henryi, A. schuhi, and A. sitesi.
Habitat description. The type locality at Río Rana (L-1906), close to the town of San Miguel Mixtepec, is in the south-central area of the Mexican state of Oaxaca, at an elevation of 712 meters. The stream at this location is 5–10 meters wide, with fast current, and boulders, cobble, and gravel (Fig. 8).
Etymology. The specific epithet is a patronym in honor of Higor D. D. Rodrigues (Instituto Oswaldo Cruz), a dear friend, colleague, and the specialist in the saucer bug genus Limnocoris.
Repository. The holotype and some paratypes are deposited in the Entomological Collection at Instituto de Ecología A.C., IEXA (Xalapa, Veracruz, México).
Type material examined. HOLOTYPE ♂. MÉXICO: OAXACA: Mpio. San Gabriel Mixtepec, km 194 carr. Puerto Escondido-Oaxaca, San Gabriel Mixtepec, Río Rana, 16º06’06.3’’N, 97º03’52.9’’W, 712 m, 03-Apr- 2015, L-1906, Reynoso-Velasco, Sites, Shepard, and Barr colls. PARATYPES: same data as holotype (1♂, 1♀); Mpio. Putla Villa de Guerrero, Pluta de Guerrero, 17º02’21.5’’N, 97º54’42.9’’W, 767 m, 30-May-2012, L-1397,
Reynoso-Velasco coll. (1♀ CNIN); same but at Pte. La Cuchara, 17º01’06.7’’N, 97º55’11.8’’W, 711 m, L-1396 (1♂; 1♂ CNIN); Mpio Valle Nacional San Mateo Yetla, 13-X-1990, E. Barrera, E. Ramirez & A. Cadena (1♂, 1♀ UMC; 1♀ MZUSP); same but 20-XI-1990, E. Barrera & A. Cadena (1♀ UMC).
description: Published as part of Reynoso-Velasco, Daniel, 2020, A new species of Limnocoris Stål (Heteroptera: Naucoridae: Limnocorinae) and new state records for species of the genus in Mexico, pp. 375-392 in Zootaxa 4860 (3) on pages 385-388, DOI: 10.11646/zootaxa.4860.3.3, http://zenodo.org/record/4413979