Platynus

Liebherr, James K. & Ivie, Michael A., 2021, Two New Platynus Bonelli (Coleoptera: Carabidae: Platynini) from Nevis and St. Kitts, Lesser Antilles, The Coleopterists Bulletin 75 (1), pp. 59-74 : 68-69

KEY TO ADULTS FOR LESSER ANTILLEAN PLATYNUS , SUBGENUS DYSCOLUS

The Lesser Antillean Platynus species , subgenus Dyscolus , comprise members of two distinct lineages. There are four species assignable to the Platynus (Dyscolus) jaegeri (Dejean) speciesgroup: Platynus alternans (Chaudoir) , Platynus ellipticus (Chaudoir) , Platynus lherminieri (Chaudoir) , and Platynus pseudellipticus Liebherr ( Liebherr and Godwin 2004). The balance of the species assemblage are members of the P. (D.) memnonius species-group ( Liebherr 1987, 1988).

1. Anterior and posterior lateral setae present on pronotum (2–5 lateral setae may be present, at least unilaterally in anterior half)………3

1 ʹ. A single anterior pronotal seta present each side, posterior seta absent ..................... 2

2. Integument dark piceous, glaucous; elytral striae deep, broad, furrow-like, intervals broadly convex; 5–7 ventral mesofemoral setae ( Liebherr 1987: fig. 9); Dominica..... ........... Platynus pseudellipticus Liebherr

2 ʹ. Integument rufopiceous, shining; elytral striae narrow, shallow, intervals slightly convex; 2–3 ventral metafemoral setae ( Liebherr 1987: fig. 10); Martinique......... ............... Platynus ellipticus (Chaudoir)

3. Elytral dorsal setae present only adjacent to the third interval, a total of 3–4 setae on each elytron ............................................. 4

3 ʹ. Elytral setae present in or adjacent to intervals 3, 5, and 7, a total of 13–15 setae on each elytron; Basse-Terre ............................... ............... Platynus alternans (Chaudoir)

4. A single pronotal lateral seta present each side at or near mid-length .................... 5

4 ʹ. Pronotum with 2–5 setae present in anterior half of lateral marginal depression at least unilaterally (if a single seta is present on one side, there are 2 or more on the other side); St. Kitts................... Platynus racquelae Liebherr and Ivie , new species

5. Standardized body length ≤ 11.5 mm ...... .................................................... 6

5 ʹ. Standardized body length> 11.5 mm ...... .................................................... 8

6. Mediobasal area of pronotum with rugose wrinkles, laterobasal pronotal impressions deep, broad, continuous to raised lateral margin .............................................. 7

6 ʹ. Mediobasal area of pronotum smooth, laterobasal pronotal impressions shallow with area laterad coplanar to raised lateral margin; Basse-Terre .......................................... .................. Platynus dejeani (Chaudoir)

7. Elytra with 4 dorsal elytral setae adjacent to third interval; laterobasal pronotal depressions with punctate surface ( Liebherr 1987: fig. 27); St. Vincent............................... ............. Platynus punctinotum Liebherr

7 ʹ. Elytra with 3 dorsal elytral setae adjacent to third interval; laterobasal pronotal depressions smooth ( Liebherr 1987: fig. 28); Basse- Terre and Martinique............................. ............ Platynus lherminieri (Chaudoir)

8. Elytral microsculpture distinctly, uniformly isodiametric ....................................... 9

8 ʹ. Elytral intervals bearing transverse microsculpture, from sculpticells with breadth 2× length, to very dense transverse lines ........ ...................................................... 10

9. Fourth metatarsomere with outer apical lobe as long as basal portion of tarsomere; pronotal hind angle rounded ( Liebherr 1987: fig. 25); Dominica...................................... ............. Platynus glaucipennis Liebherr

9 ʹ. Fourth metatarsomere with outer apical lobe about ½ length of basal portion; pronotal hind angle sharp ( Liebherr 1987: fig. 26); St. Lucia.............. Platynus luciae Liebherr

10. Elytral microsculpture a transverse mesh, the sculpticells defined by longitudinal connections between the elongate edges; standardized body length 13.7–17 mm ............. 11

10 ʹ. Elytral microsculpture of dense transverse lines, the lines not connected by crosslinkages; standardized body length 13.2 mm; Basse-Terre .............................................. .................. Platynus elongatus (Chaudoir)

11. Frons not distinctly depressed between eyes; elytral microsculpture a transverse mesh, sculpticell breadth 2× length; standardized body length 13–15.1 mm .................... 12

11 ʹ. Frons distinctly depressed between front margins of eyes; elytral microsculpture a dense transverse mesh, sculpticell breadth 3–4× length; standardized body length 15–17 mm; elytral lateral marginal depression with 16–19 setae distributed from humerus to subapical sinuation (see next couplet); Basse-Terre ..... ................. Platynus memnonius (Dejean)

12. Elytral marginal depression with 22 setae distributed from humerus to subapical sinuation; standardized body length 15.1 mm; Dominica............................................ ......... Platynus paramemnonius Liebherr

12 ʹ. Elytral marginal depression with 19 setae distributed from humerus to subapical sinuation; standardized body length 13.7 mm; Nevis …………… Platynus duportei Liebherr and Ivie , new species