Limnocoris inflatus 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 : 60-63

Limnocoris inflatus Rodrigues & Sites NEW SPECIES

( Figs. 7 , 12A–B , 13B , 14 )

Description. Female – hindwing brachypterous. HOLOTYPE, length 7.04; maximum width 5.76. Paratypes (n = 6), length 7.04–7.28 (mean = 7.11); maximum width 5.52–5.92 (mean = 5.76). General shape oval; widest across posterior region of embolia ( Figs. 7A, B ). Overall dorsal coloration yellowish-brown, brown mottled on head, pronotum, and hemelytra; hemelytral membrane brown. Dorsal surface punctate throughout ( Fig. 7A ). Ventral coloration yellow ( Fig. 7B ).

Head. Length 1.28, maximum width 2.48. Mostly yellowish with brown median markings becoming wider posteriorly, punctate. Synthlipsis 1.20. Eyes not raised above level of vertex or pronotum; thin band of cuticle lateral to anterior half of eye. Anterior margin between eyes shallowly convex; posterior margin between eyes almost straight. Maxillary plate broad basally, anterior edge triangular. Labrum width 1.20× length, distal margin narrowly rounded. Labium with three visible yellowish segments, darkening distally, extending 0.30 beyond labrum not including extruded stylets. Antenna length 0.60; 4-segmented, not exceeding lateral margin of eye; scape bulbous and rounded, pedicel quadrate; flagellomeres slender, not partially fused, with long setae; segment lengths 0.08, 0.20, 0.22, 0.12. Postgenal tubercle on posteroventral midline.

Thorax. Pronotum ground color yellowish-brown; mottled with brown marking on rectangular area behind eyes; smaller marking near mid-lateral area; shallow sulcus marking anterior border of transverse band in posterior third; anterior margin almost straight between eyes; lateral margins convergent anteriorly, evenly convex; posterior margin shallowly concave medially; posterolateral corner rounded ( Fig. 7A ); greatest width 3.36× length at midline; length at midline 1.44; maximum width at posterolateral corners 4.84. Prothorax ventrally yellow. Propleuron with shagreened area slightly extended posteriorly along lateral margin, with posterior end rounded or weakly angulate ( Fig. 7C ); elongate golden setae concentrated near proacetabulum; posterior margin convex at mid-length; posteromesal corner near prosternellum deflexed ventrally as a papilla. Probasisternum projecting anteroventrally as attenuating carina, almost bifid in lateral view. Scutellum punctate; triangular; mostly brown, lighter laterally and posteriorly; width 2.52, length 1.12. Hemelytra punctate, yellowish with prominent, irregular brown marking on corium and clavus; membrane brown, mottled; length 5.48 (chord measurement). Embolium greatest width 0.93, lateral margin mostly straight in anterior 2/3, dramatically widened in posterior third, inflection narrowly rounded and margin distinctly concave posteriorly; yellowish in anterior 2/3 and brown posteriorly, with small, brown markings in anterior 2/3 ( Fig. 7A ). Claval and intraclaval sutures present, but suppressed. Hindwings reduced, extending to near posterior margin of tergum III. Region between mesobasisternum and mesoepisternum with longitudinal row of elongate golden setae. Mesosternal carina with short anterior projection, median ridge straight, fossa deflexed ventrad, oval, poorly crenulated at lateral margins, and contains short golden hairs inside rim ( Fig. 7D ); posterior margin excavated in lateral view after fossa ( Fig. 7G ). Metasternal carina oval to teardrop-shaped, depressed medially ( Fig. 7D ); posterior margin deeply excavated in lateral view ( Fig. 7G ). Metaepimeron covered with elongate golden setae.

Legs. All leg segments yellowish, except dark-brown apex of tarsomeres III of middle and hind legs. Procoxa with cluster of stout, brown anteromedial spines. Profemur anterior margin with dense pad of orange-brown 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 1.76, tibia 1.08, tarsus 0.44; middle leg, femur 1.94, tibia 1.26, tarsomeres 1–3, 0.12, 0.30, 0.40; hind leg, femur 2.64, tibia 2.60, tarsomeres 1–3, 0.12, 0.66, 0.66.

Abdomen. Dorsally with lateral margins of terga III–VIII exposed; terga III–VI dark-brown anteriorly, yellowish posteriorly; marginal row of short yellow setae, and group of trichobothria near posterolateral corners. Lateral margin serrated, tergum V with 23 teeth ( Fig. 7E ). Posterolateral corners II–V right angled, not spinose, VI acute. Sterna mostly yellowish, dark-brown on anterolateral corners of III–VI and medially on III–IV ( Fig. 7B ); elongate golden setae generally dispersed, concentrated near midline; sternum II with sinuous row of elongate golden setae. Abdominal tergum VI symmetrical. Subgenital plate width 0.88× length; length at midline 1.12; maximum width 0.98; lateral margin almost straight, ending in a narrowly rounded apex; laterosternite VII tapered at apex ( Fig. 7F ).

Male – hindwing brachypterous. Paratypes (n = 6), length 6.96–7.12 (mean = 7.06); maximum width 5.68– 5.92 (mean = 5.77). Similar to female in general structure and coloration, except as follows: Mediotergite VI with accessory genitalic process rounded apically; posterior margin with indistinct notch on left side. Mediotergite VII posterior margin with pair of rounded, inconspicuous lateral lobes, and shallowly concave medially; mesal margin of laterotergite VII convex ( Fig. 12A ). Lateral lobe of tergum VIII with lateral margin straight in anterior half; left medial lobe poorly angled laterally at apex, with posteromesal corner rounded; right medial lobe twisted in distal half ( Fig. 12B ).

Diagnosis. Body length 6.96–7.28, body width 5.52–5.92. The shagreened area of the propleuron extends posteriorly near the lateral margin for almost half the distance of the lateral margin, with the posterior end rounded to weakly angulate ( Fig. 7C ). The mesosternal carina median ridge is straight, the fossa deflexed ventrad and oval ( Fig. 7D ), and the carina is excavated in lateral view after the fossa ( Fig. 7G ). The embolium lateral margin is distinctly widened at approximately mid-length ( Fig. 7A ). The female subgenital plate is narrowly rounded posteriorly ( Fig. 7F ).

Comparative notes. This species shares the shape of the mesosternal carina with L. burmeisteri , L. fittkaui , L. menkei , L. minutus , L. moreirai , and L. surinamensis . In addition, the dorsal coloration of the body also is similar among them. However, Limnocoris inflatus differs from them all by having the shagreened area of the propleuron extending posteriorly near the lateral margin for ca. 40% of the margin, with the posterior end rounded to weakly angulate ( Fig. 7C ), and the embolium lateral margin is distinctly widened ( Fig. 7A ). In the other six species, the shagreened pattern of the propleuron is different and the embolium lateral margin is convex ( Figs. 3A, 3C ) or with a subtle angle at the inflection point (e.g., Figs. 4A, B ), but never widened to the degree as in L. inflatus . In L. moreirai , the embolium lateral margin has the inflection angle more developed than the other five species, but it is easily distinguished by the hemelytra condition.

Distribution. This species is known only by the record of the type series, in the central region of Suriname ( Fig. 13B ). The type locality was a small blackwater stream ( Fig. 14 ).

Etymology. The specific epithet is derived from Latin for inflated, in reference to the unusually wide lateral margins of the embolia.

Type material examined. All specimens brachypterous. HOLOTYPE, ♀: SURINAME, Sipaliwini: Central Suriname Nature Reserve, Tafelberg Summit, 19 August 2013, colls. Short & Bloom, 733 m, 3º53’56.5188”, -56º10’50.9406”, Caimen Creek , pools and creek margins, SR13-0819-04B ( NZCS) . PARATYPES: same data as holotype (1♀ MZUSP; 1♁, 1♀ SEMC; 5♁, 5♀ UMC) .

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 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.

FIGURE 14. Caimen Creek, a blackwater stream in the Central Suriname Nature Reserve, the type locality of Limnocoris inflatus n. sp. Photo courtesy of Andrew Short.