Below we present the formal description and re-descriptions of eight species of Amphibolips

belonging to the ‘ niger’ complex, all from the Nearctic A. elatus Kinsey, 1937, A. gumia Kinsey, 1937, A. ufo Cuesta-Porta & Pujade-Villar sp. nov., A. jubatus Kinsey, 1937, A. maturus Kinsey, 1937, A. nebris Kinsey, 1937, A. nigra Beutenmüler, 1911, A. pistrix Kinsey, 1937 . An identification key to species is also provided.

Key to asexual females

1. Antennae with 11-12 flagellomeres (Fig. 1). Metasoma glabrous, except for the sparse pubescence on anterior part of second metasomal tergum, metasomal terga shiny smooth, usually with a conspicuous band of micropunctures in posterior margin (Fig. 1)............................................................................. Amphibolips ‘ nassa ’ group

- Antennae with 13-15 flagellomeres (Fig. 8). Metasoma completely pubescent and punctured in lateral view (Fig. 7)................................................................................... ( Amphibolips ‘ niger ’ group) 2

2. Mesoscutum rugose, without transversal carinae (Fig. 55); central and lateral propodeal areas shiny smooth with tiny piliferous points (Fig. 58)....................................................................................... 3

- Mesoscutum carinated at least on anterior half (Fig. 3), central propodeal area rugose and shiny, lateral propodeal area dull, faintly alutaceous or rugose (Figs 15, 32).................................................................. 4

3. Mesoscutellar disc coarsely rugose (Fig. 48), propodeal carina present, metapleural carina conspicuous (Fig. 46); central ocellus conspicuously smaller than lateral ocelli (Fig. 45)......................................................... nigra

- Mesoscutellar disc alutaceous, propodeal carinae absent (Fig. 56), metapleural carina indistinct; all ocelli subequal (Fig. 53)................................................................................................ pistrix

4. Mesoscutum with carinae transversally parallel on anterior half around anterior parallel lines but never forming long carinae, rugose on posterior half, (Fig. 64)............................................................... ufo sp. nov.

- Mesoscutum completely carinated, most of the carinae bent towards the posterior margin of mesoscutum (Figs 29, 38)..... 5

5. Mesosoma with variable rufous areas, but the axilla always rufous (Figs 28–29). Posterior half of mesoscutum with faded carinated-rugose sculpture and alutaceous interspaces (Fig. 29), piliferous points visible; median mesoscutal line visible on posterior margin; mesoscutellar disc strongly alutaceous with faint rugae (Fig. 30); antenna with 13 flagellomeres...................................................................................................... maturus

- Mesosoma usually completely black, rarely with chestnut areas ventrally, axilla always black (Figs 5, 22, 39). Mesoscutum uniformly strongly carinated-rugose, piliferous points absent (Figs 3, 12, 38), median mesoscutal line absent or inconspicuous; mesoscutellar disc coarsely rugose (Figs 5, 14, 39); antenna with 14-15 flagellomeres (Figs 8, 26, 40).................. 6

6. Lower face, mesopleura, propodeum and legs chestnut (Figs 35, 37), antenna completely rufous-brown (Fig 40); lower face finely coriaceous without carinae.................................................................... nebris

- Head and mesosoma black (Figs 2–5, 18–22), at least first half of antennae black (Fig. 8, 25), lower face carinate-rugose (Figs 2, 10, 25)............................................................................................ 7

7. Notauli distinct on posterior 1/3 of mesoscutum (Figs 20, 22), mesoscutellar foveae rounded, divided by a long strong carina extending the full-length of the foveae (Fig. 22)........................................................ jubatus

- Notauli absent or only slightly impressed on posterior margin of mesoscutum (Figs 3, 12), mesoscutellar foveae transversal, divided by a short thin carina, extending to half of the length of the foveae (Figs 5, 14).............................. 8

8. Lower face finely rugose with distinct piliferous points (Fig. 2); malar space without striae radiating from clypeus; 2r vein of fore wing strongly projecting into radial cell (Fig. 6)..................................................... elatus

- Lower face strongly carinated, without piliferous points (Fig. 10); malar space with striae radiating from clypeus; 2r vein short, slightly projecting into radial cell (Fig. 17)............................................................. gumia