Limnocoris, Stål, 1860

Rodrigues, Higor D. D. & Sites, Robert W., 2019, Revision of Limnocoris (Heteroptera: Nepomorpha: Naucoridae) of North America, Zootaxa 4629 (4), pp. 451-497 : 455-456

Key to the species of Limnocoris of North America

1. Embolium with lateral margin prolonged into a long and curved spine; hemelytral membrane distinctly reduced ( Fig. 11A ).......................................................................... Limnocoris moapensis (La Rivers)

1’. Embolium with lateral margin convex, not prolonged into a long and curved spine; hemelytral membrane developed (e.g., Figs. 3A, C ).............................................................................................. 2

2. Posterior margin of propleuron shallowly convex at mid-length ( Figs. 1 B–D); mesosternum with longitudinal row of golden setae ( Fig. 2C ); abdominal sterna with dispersed elongate golden setae ( Fig. 2H ); lateral margin of female subgenital plate with elongate golden setae ( Fig. 2H ).......................................................................... 3

2’. Posterior margin of propleuron straight ( Fig. 1A ); mesosternum without longitudinal row of golden setae ( Fig. 2D ); abdominal sterna without dispersed elongate setae (e.g, Fig. 2G ); lateral margin of female subgenital plate without elongate golden setae (e.g., Fig. 2G )....................................................................................... 10

3. Posterolateral corners of abdominal segments III–V produced posteriorly, spinose ( Fig. 2E ); body length ≥ 9.20 mm ...... 4

3’. Posterolateral corners of abdominal segments III–V not produced posteriorly, narrowly rounded to right angled, not spinose ( Fig. 2F ); body length <9.20 mm ........................................................................ 5

4. Pubescent area of propleuron extended posteriorly to approximately halfway along lateral margin ( Fig. 1C ); fossa of mesosternal carina shallow ( Fig. 17D ).................................................. Limnocoris virescens Montandon

4’. Pubescent area of propleuron not extended posteriorly along lateral margin (as in Fig. 1D ); fossa of mesosternal carina deep ( Fig. 9D ).......................................................................... Limnocoris major n. sp.

5. Mesosternal carina with elongate golden setae on lateral margin; fossa shallow, elongate, and narrow ( Figs. 3D, F ).................................................................................. Limnocoris chaetocarinatus n. sp.

5’. Mesosternal carina without elongate setae on lateral margin; fossa not as above (e.g., Figs. 4C, 4E , 13C, 13E )............ 6

6. Pubescent area of propleuron not extended posteriorly on lateral margin (as in Fig. 1D ); fossa of mesosternal carina deep, elliptical, sometimes with subtle angles at greatest width ( Figs. 13C, E ); female subgenital plate with posterior margin evenly convex ( Fig. 13D )........................................................... Limnocoris panamensis La Rivers

6’. Pubescent area of propleuron distinctly extended posteriorly on lateral margin ( Fig. 1B ); fossa of mesosternal carina shallow and semicircular ( Fig. 4C ) or fossa obscured by lateral margins touching at midline ( Figs. 5C , 15D , 16 D–E); female subgenital plate with posterior margin tapering posteriorly ( Figs. 4D , 5D , 15E , 16G )......................................... 7

7. Distal margin of labrum bluntly pointed ( Fig. 16F ); mesosternal carina without excavation posterior to fossa in lateral view ( Figs. 16H )................................................................. Limnocoris signoreti Montandon

7’. Distal margin of labrum distinctly acuminate ( Figs. 4C , 5C , 15D ); mesosternal carina with small excavation posterior to fossa in lateral view ( Figs. 2A , 4E , 5E )......................................................................... 8

8. Fossa of mesosternal carina with lateral margins generally touching each other at middle, leaving a wide, circular or subtriangular posterior opening and small separation anteriorly ( Fig. 4C ); lateral lobe of male tergum VIII with lateral margin shallowly concave in anterior half ( Fig. 6D ); posterior margin of male sternum VIII with medial notch (as in Fig. 18B ).......................................................................................... Limnocoris hintoni La Rivers

8’. Fossa of mesosternal carina with lateral margins touching each other along most of its length, leaving only a small opening at anterior and posterior ends ( Figs. 5C , 15D ); lateral lobe of male tergum VIII with lateral margin straight in anterior half ( Figs. 6F , 19B ); posterior margin of male sternum VIII without medial notch........................................... 9

9. Body color usually brown to dark brown; hemelytral membrane without pale spot medially ( Fig. 5A )............................................................................................ Limnocoris inornatus Montandon

9’. Body color usually light brown to yellowish; hemelytral membrane with pale spot medially ( Figs. 15A, C )......................................................................................... Limnocoris pygmaeus La Rivers

10. Mesosternal carina with median projection ( Figs. 2B , 18E ); fossa with small aperture anteriorly ( Figs. 2D , 18C ); posterior margin of male sternum VIII with medial notch ( Fig. 18B ).................................. Limnocoris zacki n. sp.

10’. Mesosternal carina without median projection ( Figs. 7 F–G, 8E, 12E); fossa without anterior aperture ( Figs. 7D , 8C , 12C ); posterior margin of male sternum VIII without medial notch.................................................. 11

11’. Mesosternal carina with anterior projection lower than fossa ( Figs. 7 F–G, 8E); fossa not open anteriorly, ranging from rounded to subtriangular; ridge without sulcus ( Figs. 7D , 8C )........................................................ 12

12. Region between anterior projection and fossa of mesosternal carina almost straight or slightly sinuate in lateral view, and angled dorsoventrally ~20 degrees from the long body axis ( Figs. 7 F–G); antennal flagellomeres not partially fused; apex of left medial lobe of male tergum VIII distinctly angled laterally ( Fig. 10B ).......................... Limnocoris insularis Champion

12’ Region between anterior projection and fossa of mesosternal carina concave in lateral view, and angled dorsoventrally ~70 degrees from the long body axis ( Fig. 8E ); antennal flagellomeres partially fused; apex of left medial lobe of male tergum VIII slightly angled laterally ( Fig. 10D )................................................... Limnocoris lutzi La Rivers

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 3. Limnocoris chaetocarinatus n. sp. (A) Dorsal habitus and (B) ventral habitus of female holotype, hindwing brachypterous (UMC), (C) dorsal habitus of male paratype, hindwing macropterous (UMC) (D) ventral view of head and part of thorax, white arrow indicates elongate hairs on the mesosternal carina, (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. cls = claval suture, cor = corium, emb = embolium, lbr = labrum, mbr = hemelytral membrane, mbs = mesobasisternum, mpl = maxillary plate, mps = mesoepisternum, mtc = metasternal carina, mtp = metapleuron, pbs = probasisternum, plc = posterolateral corner of pronotum, prp = propleuron, pst = prosternellum.

FIGURE 4. Limnocoris hintoni La Rivers. (A) Dorsal habitus and (B) ventral habitus of female paratype, hindwing macropterous (USNM), (C) ventral view of head and part of thorax, (D) terminal abdominal sterna of female, and (E) lateral view of meso- and metasternal carinae, arrow indicates small projection between anterior projection and fossa. Size bar = 1.00 mm and applies only to Figs. A–B.

FIGURE 5. Limnocoris inornatus Montandon. (A) Dorsal habitus and (B) ventral habitus of female, hindwing macropterous (UMC), (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 6. Structures of male terminalia. (A, C, E) 6th and 7th abdominal terga, (B, D, F) 8th abdominal tergum. (A–B) Limnocoris chaetocarinatus n. sp., (C–D) L. hintoni, and (E–F) L. inornatus. agp = accessory genitalic process, ll = lateral lobe, lml = left medial lobe, ltr = lateral lobe of tergum VI (delimited by dotted line), ml = medial lobe, rml = right medial lobe, snt = small notch.

FIGURE 7. Limnocoris insularis Champion. (A) Dorsal habitus and (B) ventral habitus of female holotype, hindwing brachypterous (BMNH), (C) dorsal habitus of female holotype of L. alcorni n. syn., hindwing macropterous (CAS), (D) ventral view of part of thorax, (E) terminal abdominal sterna of female, (F) lateral view of mesosternal carina of holotype, and (G) lateral view of meso- and metasternal carinae of holotype of L. alcorni n. syn. Size bar = 1.00 mm and applies only to Figs. A–C.

FIGURE 8. Limnocoris lutzi La Rivers. (A) Dorsal habitus and (B) ventral habitus of male paratype [=allotype], hindwing brachypterous (CAS), (C) ventral view of head and 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 9. Limnocoris major n. sp. (A) Dorsal habitus and (B) ventral habitus of female holotype, hindwing brachypterous (UMC), (C) dorsal habitus of female paratype, hindwing macropterous (MZUSP), (D) ventral view of part of thorax, (E) ter- minal 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 10. Structures of male terminalia. (A, C, E) 6th and 7th abdominal terga, (B, D, F) 8th abdominal tergum. (A–B) Limnocoris insularis, (C–D) L. lutzi, and (E–F) L. major n. sp.

FIGURE 11. Limnocoris moapensis (La Rivers). (A) Dorsal habitus and (B) ventral habitus of female, hindwing brachypterous (UMC), (C) ventral view of head and part of thorax, (D) terminal abdominal sterna of female, (E) lateral view of meso- and metasternal carinae. Size bar = 1.00 mm and applies only to Figs. A–B.

FIGURE 12. Limnocoris nanus n. sp. (A) Dorsal habitus and (B) ventral habitus of male holotype, hindwing brachypterous (UMC), (C) ventral view of part of thorax, arrow indicates fine sulcus on midline of anterior ridge, (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 13. Limnocoris panamensis La Rivers. (A) Dorsal habitus and (B) ventral habitus of female paratype, hindwing brachypterous (USNM), (C) ventral view of part of head and 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 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 16. Limnocoris signoreti Montandon. (A) Dorsal habitus and (B) ventral habitus of male, hindwing macropterous (UMC), (C) dorsal habitus of female holotype of L. laucki n. syn., hindwing macropterous (CAS), (D–E) ventral view of part of thorax, (F) head and part of prosternum, (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 17. Limnocoris virescens Montandon. (A) Dorsal habitus and (B) ventral habitus of male, hindwing brachypterous (EMEC), (C) dorsal habitus of male, hindwing macropterous (EMEC), (D) ventral view of part of 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 18. Limnocoris zacki n. sp. (A) Dorsal habitus and (B) ventral habitus of male holotype, hindwing brachypterous (UMC), with detail of notch at posterior margin of abdominal sternum VIII, (C) ventral view of part of head and 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 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.