Limnocoris yanomami Rodrigues & Sites, 2023

Rodrigues, Higor D. D. & Sites, Robert W., 2023, Revision of Limnocoris Stål (Heteroptera: Nepomorpha: Naucoridae) of the Guiana Shield and Amazon regions, Zootaxa 5284 (1), pp. 44-76 : 70-74

Limnocoris yanomami Rodrigues & Sites NEW SPECIES

( Figs. 1A , 11 , 12E –F, 13A )

Description. Male – hindwing brachypterous. HOLOTYPE, length 5.75; maximum width 4.30. Paratypes (n = 5), length 5.51–5.75 (mean = 5.60); maximum width 4.20–4.32 (mean = 4.27). General shape oval; widest across embolia. Overall dorsal coloration brown, hemelytral membrane slightly darker, dark mottled on pronotum and hemelytra. Dorsal surface with fine granulations and punctate throughout ( Fig. 11A ). Ventral coloration dark-brown ( Fig. 11B ).

Head. Head length 1.30, maximum width 1.95. Mostly brown with dark-brown median markings becoming wider posteriorly, weakly punctate. Synthlipsis 0.97; eyes not raised above level of vertex or pronotum. Anterior margin between eyes convex. Maxillary plate tumescent anteriorly. Labrum width 2.25× length, subpentagonal, distal margin tapered. Labium with three visible brownish segments, darkening distally, extending 0.47 beyond labrum not including extruded stylets. Antenna length 0.40; not exceeding lateral margin of eye; pedicel quadrate; flagellomeres slender, partially fused, with long setae; segments 1, 2, 3+4 lengths 0.03, 0.13, 0.28. Postgenal tubercle on posteroventral midline.

Thorax. Pronotum ground color brown, rectangular area behind eyes darker, lateral margins light-brown; a narrow, convergent posteriorly, dark-brown stripe starting near posterolateral corner of eye; other smaller dark-brown markings generally dispersed; transverse sulcus marking anterior border of transverse band in posterior 1/3; anterior margin shallowly concave between eyes; lateral margins convergent anteriorly, evenly convex; posterior margin shallowly concave medially; posterolateral corner rounded; greatest width 3.61× length at midline; length at midline 1.05; maximum width at posterolateral corner 3.80. Prothorax ventrally dark-brown medially, light-brown laterally. Propleuron with shagreened area extended posteriorly along entire lateral margin; posterior margin almost straight ( Fig. 1A ); posteromesal corner near prosternellum flat. Probasisternum with median carina deflexed ventrad anteriorly, truncate basally. Scutellum punctate; triangular; dark-brown, lighter at anterolateral corners; width 2.00, length 0.82. Hemelytra punctate, brown, with darker and lighter markings throughout, mostly on clavus and corium; membrane darker and mottled ( Fig. 11A ); length 3.82 (chord measurement). Embolium greatest width 0.50, lateral margin convex, light-brown in anterior 3/4 and brown posteriorly. Claval and intraclaval sutures absent. Hindwings extending to tergum I. Region between mesobasisternum and mesoepisternum without longitudinal row of elongate golden setae. Mesosternal carina with median ridge straight; fossa transversely notched, forming an inverted Ushape (lateral view); not excavated on posterior margin in lateral view ( Fig. 11E ). Metasternal carina with fossa oval to teardrop-shaped, slightly depressed medially ( Fig. 11B ); posterior margin not excavated in lateral view ( Fig. 11E ).

Legs. All leg segments brown, except dark-brown apical part of tarsomere III of middle and hind legs. Procoxa with cluster of stout, brown anteromedial spines. Profemur anterior margin with dense pad of setae without associated spines, posterior margin with row of short, brown spines along basal half. 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, brown spines on anterior margin. Meso- and metatibiae with ventrolateral, ventromedial, dorsolateral, and dorsomedial rows of stout brownish spines; meso- and metatibiae with two transverse rows of spines distally, one each on lateral and mesal margins. Meso- and metatibiae and metatarsus with long, pale 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 1.58, tibia 1.18, tarsus 0.22; middle leg, femur 1.37, tibia 1.12, tarsomeres 1–3, 0.12, 0.20, 0.32; hind leg, femur 1.88, tibia 1.97, tarsomeres 1–3, 0.12, 0.61, 0.55.

Abdomen. Dorsally with lateral margins of terga III–VIII exposed; terga III–V brown on anterior third, light-brown posteriorly; marginal row of short yellow setae, and group of trichobothria near posterolateral corners. Lateral margin of abdomen with minute serration. Posterolateral corners of II–VI narrowly rounded to right angled, not spinose. Sterna brown, covered by golden pubescence, without dispersed elongate golden setae; sternum II without irregular patch or row of elongate golden setae ( Fig. 11B ). Abdominal tergum VI asymmetrical. Mediotergite VI with accessory genitalic process narrowly rounded apically. Posterior margin of mediotergite VII almost straight, without distinct lateral lobes ( Fig. 12E ). Lateral lobe of tergum VIII with lateral margin shallowly concave in proximal half; left medial lobe angled laterally at apex, with posteromesal corner rounded; right medial lobe twisted in distal half ( Fig. 12F ).

Female – hindwing brachypterous. Paratypes (n = 3), length 5.60–5.80 (mean = 5.72); maximum width 4.22–4.30 (mean = 4.26). Similar to male in general structure and coloration, except as follows: Abdominal tergum VI symmetrical. Subgenital plate width 1.00× length; length at midline 0.80; maximum width 0.80; lateral margins without elongate golden setae at mid-length; posterior margin narrowly rounded ( Fig. 11D ).

Diagnosis. Body length 5.51–5.80, body width 4.20–4.32. This species is easily distinguished by its transversely notched fossa of the mesosternal carina ( Fig. 11E ). Also, the shagreened area of the propleuron is broad and extends along the lateral margin to near the posterolateral corner (as in Fig. 1C ). Sternum II lacks a patch or row of elongate golden setae ( Fig. 11B ).

Comparative notes. This small species is most similar to L. illiesi and L. reynosoi in body length and absence of elongate golden setae on mesosternum and abdominal sternum II. They can be easily separated by the shape of the mesosternal carina and the female subgenital plate. In addition, the posterolateral corner of male abdominal tergum V is rounded to right-angled in L. yanomami , and spinose in L. illiesi and L. reynosoi .

Distribution. This species is known only by the record of the type locality in the state of Roraima, on the border between Brazil and Venezuela ( Fig. 13A ).

Etymology. The specific epithet honors the indigenous Yanomami people, who inhabit the area where the specimens were collected.

Type material examined. All specimens brachypterous. HOLOTYPE, ♁: BRAZIL, Roraima, Área Indígena Yanomami, 2150, Parque Indígena Xitei-Xidea , Rio Thirei-ú , [02º36’N, 63º52’W], 18.IV.1997, V. Py-Daniel & U. Barbosa col. ( MZUSP) . PARATYPES: same data as holotype (9♁, 3♀ MZUSP; 3♁, 1♀ INPA)

Figures

FIGURE 1. Structures of Limnocoris. (A–B) Part of thorax in ventral view, (A) L. yanomami n. sp., (B) L. surinamensis n. stat., white arrow indicates row of elongate golden setae on mesosternum (C) Propleuron of L. reynosoi, white arrow indicates posterior end of shagreened area. (D–F) Lateral view of mesosternal carina, (D) L. pusillus, (E) L. reynosoi, (F) L. illiesi. (G–H) Dorsal view of abdominal segments III–V, (G) L. pusillus, (H) L. reynosoi, white arrows indicate posterolateral corners. (I–J) Left abdominal sternum II (circled), (I) L. pusillus, (J) L. reynosoi. (K–N) Terminal abdominal sterna of female, (K) L. illiesi, (L) L. minutus, (M) L. pusillus, (N) L. reynosoi.

FIGURE 11. Limnocoris yanomami Rodrigues & Sites n. sp. (A) Dorsal habitus and (B) ventral habitus of male holotype, hindwing brachypterous (MZUSP), (C) ventral view of head and part of thorax, (D) terminal abdominal sterna of female, and (E) lateral view of meso- and metasternal carinae. Size bar = 1.00 mm and applies only to Figs. A–B.

FIGURE 12. Structures of male terminalia. (A, C, E) 6th and 7th abdominal terga, (B, D, F) 8th abdominal tergum. (A–B) Limnocoris inflatus n. sp., white arrows indicate the small, rounded, lateral lobes of 7th abdominal tergum, (C–D) L. moreirai n. sp., and (E–F) L. yanomami n. sp.

FIGURE 13. Distribution records for nine species of Limnocoris in South America.