Limnocoris moreirai 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 : 65-68

Limnocoris moreirai Rodrigues & Sites NEW SPECIES

( Figs. 9 , 12C–D , 13A )

Description. Female – hindwing brachypterous. HOLOTYPE, length 6.00; maximum width 4.55. Paratype (n = 1), length 6.12; maximum width 4.62. General shape oval; widest across embolia. Overall dorsal coloration yellowish-brown, brown mottled on pronotum, hemelytra, and abdominal terga. Dorsal surface with fine granulations and punctate throughout ( Fig. 9A ). Ventral coloration brown ( Fig. 9B ).

Head. Head length 0.90, maximum width 1.97. Mostly yellow with brown medially and posteriorly. Synthlipsis 0.85; eyes not raised above level of vertex or pronotum. Anterior margin between eyes convex. Maxillary plate broad basally, anterior edge triangular. Labrum width 1.1× length, pentagonal, distal margin tapered. Labium with three visible segments, brown, extending 0.3 beyond labrum not including extruded stylets. Antenna, length 0.42; not exceeding lateral margin of eye; pedicel subrectangular; flagellomeres slender, partially fused, with long seta; segments 1, 2, and 3+4 lengths: 0.03, 0.13, 0.24. Postgenal tubercle on posteroventral midline.

Thorax. Pronotum ground color yellowish-brown, rectangular area behind eyes darker, lateral margins yellowish; other smaller brown markings generally dispersed; transverse sulcus markings anterior border of transverse band in posterior 1/4; anterior margin shallowly concave between eyes; lateral margins convergent anteriorly, evenly convex; posterior margin convex; posterolateral corner rounded; greatest width 3.5× length at midline; length at midline 1.10; maximum width at posterolateral corner 3.90. Prothorax ventrally brown medially, yellowish-brown laterally. Propleuron shagreened, with narrow, pruinose band posteriorly; posterior margin convex at mid-length ( Fig. 9C ); posteromesal corner near prosternellum flat. Probasisternum with median carina deflexed ventrad anteriorly in lateral view with small indentation, divided in two posteriorly. Scutellum with fine granulations; triangular; brown, lighter at corners; width 2.05, length 0.93. Hemelytra with fine granulations, slightly punctate, brown, with darker and lighter markings throughout, mostly on corium and embolium; membrane mottled, left membrane dull, right membrane shiny; length 4.28 (chord measurement); lateral margin beyond embolium mostly straight. Corium with posterior margin perpendicular to body axis. Embolium greatest width 0.70, lateral margin convex, slightly widened at posterior third, inflection rounded and margin distinctly concave; yellowish-brown in anterior 3/4 and dark-brown posteriorly, with small, brown markings in anterior 2/3. Claval and intraclaval sutures absent. Hindwings reduced, not exceeding abdominal tergum II. Region between mesobasisternum and mesoepisternum without longitudinal row of elongate golden setae. Mesosternal carina with median ridge straight; fossa oval, shallow, deflexed ventrad ( Fig. 9C ); excavated on posterior margin in lateral view ( Fig. 9E ). Metasternal carina with fossa oval to teardrop-shaped, slightly depressed medially ( Fig. 9C ); posterior margin not excavated in lateral view ( Fig. 9E ).

Legs. All leg segments medium-brown to light-brown. 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 1.45, tibia 0.78, tarsus 0.38; middle leg, femur 1.38, tibia 0.95, tarsomeres 1–3, 0.13, 0.25, 0.28; hind leg, femur 2.02, tibia 1.90, tarsomeres 1–3, 0.11, 0.52, 0.55.

Abdomen. Dorsally with terga III–VI widely exposed; terga III–VI dark-brown anteriorly, light-brown posteriorly; marginal row of elongate yellow setae, and group of trichobothria near posterior third. Lateral margin serrate. Posterolateral corners of II–V narrowly rounded to right-angled, not spinose, VI spinose. Sterna brown, covered by golden pubescence, without dispersed elongate golden setae; small and rounded dark-brown spots near lateral margins of sterna III–VI; sternum II without irregular patch or row of elongate golden setae. Subgenital plate width 0.96× length; length at midline 0.85; maximum width 0.82; lateral margins without tuft of elongate golden setae at mid-length, tapering posteriorly in apical 2/3; posterior margin broadly rounded; laterosternites VII and VIII slightly acuminate posteriorly ( Fig. 9D ).

Male – Hindwing brachypterous. Paratypes (n = 2), length 5.75–5.90; maximum width 4.52–4.55. Similar to female in general structure and coloration, except as follows: Abdominal tergum VI asymmetrical. Mediotergite VI with accessory genitalic process rounded apically. Posterior margin of mediotergite VII convex, with pair of indistinct lateral lobes; laterotergite VII with mesal margin straight ( Fig. 12C ). Lateral lobe of tergum VIII with lateral margin shallowly convex in anterior half; left medial lobe poorly angled laterally at apex, with posteromesal corner rounded; right medial lobe twisted in distal third ( Fig. 12D ).

Diagnosis. Body length 5.75–6.12, body width 4.52–4.62. This species can be distinguished from all other species of the genus by the propleuron shagreened pattern, which, except for a posterior pruinose band, occupies almost the entire propleuron ( Fig. 9C ). The corium has the posterior margin perpendicular to the body axis, and the lateral margin of hemelytral membrane is almost straight ( Fig. 9A ), and not convex as usually occurs in congeners. Also, the row of elongate golden setae between mesobasisternum and mesoepisternum is absent, and the mesosternal carina has the median ridge straight, with fossa oval, shallow ( Fig. 9C ), and deflexed ventrad ( Fig. 9E ).

Comparative notes. This species has the shape of the mesosternal carina and the serration of the lateral margin of the abdomen similar to those of L. burmeisteri , L. fittkaui , L. inflatus , L. menkei , L. minutus , and L. surinamensis . In all of these species, the median ridge of the mesosternal carina is straight, and the fossa is rounded to oval, deflexed ventrad, and with a posterior excavation in lateral view. However, L. moreirai can be easily differentiated from them by the absence of the longitudinal row of golden setae on the mesosternum ( Fig. 9C ), which is present in the other species. Also, the corium posterior margin is perpendicular to the body axis, and the lateral margin of the hemelytral membrane is almost straight ( Fig. 9A ), whereas in the other species the corium posterior margin is angled at approximately 45 degrees, and the lateral margin of the hemelytral membrane is convex ( Figs. 3A , 4A–B , 7A , 8A , 10A ).

Distribution. This species is known only from the type locality, in S„o Gabriel da Cachoeira, upper Rio Negro, in northern Brazil ( Fig. 12A ).

Etymology. The specific epithet honors our colleague Felipe F. F. Moreira (Instituto Oswaldo Cruz, Rio de Janeiro, Brazil), for his many taxonomic contributions to the knowledge of the Neotropical aquatic and semiaquatic Heteroptera.

Type material examined. All specimens brachypterous. HOLOTYPE, ♀: BRAZIL, Amazonas, S „o Gabriel da Cachoeira, Igarapé Muiá, 00º06’N, 66º52’W, 25.VIII.2011, R. Ferreira-Keppler, P.V. Cruz, A. Fernandes & E.A. Reis col. ( MZUSP) . PARATYPES: same data as holotype (1♁ MZUSP; 1♁, 1♀ INPA) .

Figures

FIGURE 3. Limnocoris burmeisteri De Carlo. (A) Dorsal habitus and (B) ventral habitus of female hindwing brachypterous (from French Guiana), (C) dorsal habitus of hindwing macropterous (from Mato Grosso, Brazil), (D) ventral view of part of head and thorax, (E) lateral margin of male abdominal segment V in ventral view, (F) terminal abdominal sterna of female, and (G) lateral view of meso- and metasternal carinae. Size bar = 1.00 mm and applies only to Figs. A–C.

FIGURE 4. Limnocoris fittkaui De Carlo. (A) Dorsal habitus of male paratype hindwing brachypterous (INPA), (B) dorsal habitus and (C) ventral habitus of female hindwing macropterous (from Amazonas, Venezuela), (D) ventral view of part of head and thorax, (E) ventral view of abdominal segments IV–VI of female, (F) ventral view of abdominal segments V–VI of male, black arrow indicates posterolateral corner of segment V, (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 7. Limnocoris inflatus Rodrigues & Sites n. sp. (A) Dorsal habitus and (B) ventral habitus of female paratype, hindwing brachypterous (MZUSP), (C) propleuron, black arrow indicates posterior end of shagreened area, (D) ventral view of head and part of thorax, (E) lateral margin of female abdominal segment V in ventral view, (F) terminal abdominal sterna of female, and (G) lateral view of meso- and metasternal carinae. Size bar = 1.00 mm and applies only to Figs. A–B.

FIGURE 8. Limnocoris menkei La Rivers. (A) Dorsal habitus and (B) ventral habitus of male paratype, hindwing brachypterous (CAS), (C) dorsal habitus of male paratype of L. birabeni De Carlo n. syn. (INPA), (D) ventral view of head and part of thorax, black arrow indicates posterior end of propleuron shagreened area, (E) dorsal view of abdominal segments III–V, black arrows indicate posterolateral corners, (F) terminal abdominal sterna of female, and (G) lateral view of meso- and metasternal carinae. Size bar = 1.00 mm and applies only to Figs. A–C.

FIGURE 9. Limnocoris moreirai Rodrigues & Sites n. sp. (A) Dorsal habitus and (B) ventral habitus of female holotype, hindwing brachypterous (MZUSP), (C) ventral view of part of thorax, white arrow indicates posterior margin of propleuron convex at mid-length, propleuron pruinose area delimited by dotted line, (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 10. Limnocoris surinamensis Nieser n. stat. (A) Dorsal habitus and (B) ventral habitus of female paratype, hindwing brachypterous (USNM), (C) ventral view of part of head and thorax, (D) ventral view of abdominal segments V–VI of male, black arrow indicates posterolateral corner of segment V, (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–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.