Key to subfamilies of Liviidae and genera of Liviinae: adults

1. Three ventral sense organs on metafemur in basal position (Fig. 6E) ......................................................................... Euphyllurinae

- Three ventral sense organs on metafemur in medial or submedial position (Fig. 6F–N) ...............................................................2

2. Metabasitarsus bearing two sclerotized spurs.........................................................................................Neophyllurinae: Neophyllura

- Metabasitarsus lacking sclerotized spurs… Liviinae ................................................................................................................................3

3. Head with small preocular sclerite between eye and antennal insertion (Fig. 3B). Apex of metatibia with thorn-like setae posteriorly (Fig. 7B, D) or with one to five peg-like setae laterally adjacent to a spur (Fig. 7C); apical spurs always sclerotized, relatively evenly spaced, forming a posteriorly open crown (Fig. 7B)… Liviini ................................................................................4

- Head without preocular sclerite (Fig. 3A). Apex of metatibia lacking thorn-like setae posteriorly or peg-like setae adjacent to apical spurs; unsclerotized bristle-like setae may be present anteriorly between apical spurs (Fig. 7J, K); apical spurs are sometimes grouped (Fig. 7E, F) or weakly sclerotized (Fig. 7H, I, L)…Paurocephalini................................................................8

4. Pterostigma of forewing membranous, broad, and long (Fig. 8C). Metafemur with a group of stout, long setae apically (Fig. 6O). Apex of metatibia bearing a row of two to five peg-like setae adjacent to a spur laterally (Fig. 7C) ....................................5

- Pterostigma of forewing leathery, narrow and short or reduced (Fig. 8A). Metafemur lacking stout, long setae apically. Metatibia either with a single peg-like seta adjacent to the most lateral apical spur or with several irregularly spaced thorn-like setae postero-apically (Fig. 7B, D) ......................................................................................................................................................6

5. Frons triangular (Fig. 3C). Antennal segment 3 as long as, or longer than, segments 4–6 together. Forewing with vein M much longer than M 1 + 2 .............................................................................................................................................................. Anomoterga

- Frons elongate, parallel-sided (Fig. 3E). Antennal segment 3 not longer than segments 4–6 together. Forewing with vein M about as long as M 1 + 2 ............................................................................................................................................................ Camarotoscena

6. Subgenae not differentiated into separate sclerites. Metatibia with 9 or 10 apical metatibial spurs and one peg-like seta adjacent to inner spurs, lacking thorn-like setae postero-apically............................................................................................... Syntomoza

- Subgenae differentiated into a separate sclerite on either side (Fig. 3D, F). Metatibia with three to eight apical metatibial spurs, bearing thorn-like setae postero-apically, lacking peg-like setae adjacent to inner spur (Fig. 7B, D)................................7

7. Head with transverse carina between vertex and genae anteriorly (Fig. 2D); vertex lacking anterior lobes. Antennal segment 3 longer than any other segment .................................................................................................................................................. Aphorma

- Vertex forming lobes anteriorly (Fig. 2A). Antennal segment 2 longer than any other segment… Livia

8. Apical metatibial spurs weakly sclerotized, pale brown..........................................................................................................................9

- Apical metatibial spurs strongly sclerotized, black ............................................................................................................................... 12

9. Metatibia with stout spurs laterally similar to those apically (Fig. 7L).......................................................................... Paurocephala

- Metatibia devoid of stout spurs laterally (Fig. 7H, I) ........................................................................................................................... 10

10. Body conspicuously flattened; wings held almost horizontally (Fig. 1L). Forewing widest in basal third. Antenna with a single subapical rhinarium on each of segments 4 and 6–9; segments 3–5 with fine bifid setae ...................................... Woldaia

- Body not conspicuously flattened; wings held roof-like over the body (Fig. 1H, I). Forewing widest in the middle or apical third. Antenna with a single subapical rhinarium on each of segments 4, 6, 8, 9, and sometimes 3; lacking bifid setae ........ 11

11. Male proctiger lacking elongate or small rounded lateral plates posteriorly (Fig. 9A). Distal portion of aedeagus often strongly swollen basally (Fig. 9G). Head often strongly transverse, vertex about a quarter or a third as long as vertex width (Fig. 2B). Clypeus large, truncate anteriorly................................................................................................................................ Klyveria

- Male proctiger with elongate or small rounded lateral plates posteriorly (Fig. 9B). Distal portion of aedeagus hardly swollen basally (Fig. 9H). Head moderately transverse, vertex about a third to half as long as vertex width. Clypeus small or medium-sized, rounded anteriorly....................................................................................................................................................................... Liella

12. Vein C + Sc of forewing widened, not clearly delimited from cell; pterostigma divided into a basal or anterior coriaceous part and an apical or posterior membranous part (sometimes indistinct) (Fig. 8B, arrow). Metatibia with distinctly grouped spurs as (1–2) + (3–5) and/or lateral spurs on thumb-like processes longer than spurs (Fig. 7E, F).................. Diclidophlebia

- Vein C + Sc of forewing not widened, clearly delimited from cell; pterostigma uniform, never divided into a basal coriaceous and apical membranous part (Fig. 8C). Metatibia with ungrouped or grouped apical spurs, lateral spurs rarely on thumb-like processes (Fig. 7G, J, K) ............................................................................................................................................................................. 13

13. Metapostnotum with small tubercle or shallow longitudinal ridge (Fig. 4A). Mesosternum shallowly concave along anterior margin; pleurosternal suture indistinct; basisternum large oval to rhomboidal or indistinct; katepisternum small antero-laterally. Apex of metatibia with a posteriorly open crown of 7–11, evenly or unevenly spaced spurs of similar size; lacking weakly sclerotized bristle-like setae between spurs (Fig. 7G)........................................................................................ Haplaphalara

- Metapostnotum with laterally compressed tooth (Fig. 4C). Mesosternum concave anteriorly with hump in the middle; pleurosternal suture well visible; basisternum large, triangular; katepisternum large antero-laterally. Apex of metatibia with 5–10, sometimes indistinctly, grouped spurs; with antero-lateral unsclerotized bristle-like setae separating apical spurs (Fig. 7J, K) .............................................................................................................................................................................................. Melanastera

Key to genera of Liviinae: immatures

1. Tarsal arolium fan-shaped, sessile (Fig. 8K). Antennal flagellum lacking sectasetae; antenna seven or eight segments… Liviini ................................................................................................................................................................................................................2

- Tarsal arolium petiolate; petiole often with lateral appendages; arolium small relative to pedicel (Fig. 8L, N). Antennal flagellum bearing sectasetae; if absent, then antenna three segments…Paurocephalini .....................................................................6

2. On Salicaceae (and perhaps Cunoniaceae)...............................................................................................................................................3

- On other host families ...................................................................................................................................................................................5

3. Anus in terminal position............................................................................................................................................................. Syntomoza

- Anus in ventral position ................................................................................................................................................................................4

4. Mid- and hindlegs with massive peg-like spurs ..................................................................................................................... Anomoterga

- Mid- and hindlegs lacking massive peg-like spurs .......................................................................................................... Camarotoscena

5. Caudal plate bearing dorsal and marginal sectasetae. On Ranunculaceae ........................................................................... Aphorma

- Caudal plate lacking sectasetae. On Cyperaceae and Juncaceae .................................................................................................... Livia

6. Body usually lacking minute clavate setae dorsally. Abdomen never with pore fields in addition to circumanal ring ..............7

- Body bearing minute clavate setae dorsally. Abdomen usually bearing pore fields in addition to circumanal ring ...................8

7. Antennal flagellum never subdivided. Sectasetae on outer margin of abdomen based upon extended tubercles, if indistinct then antennal flagellum lacking sectasetae ........................................................................................................................................ Liella

- Antennal flagellum usually (indistinctly) subdivided; always with sectasetae. Sectasetae on outer margin of abdomen not based upon extended tubercles.............................................................................................................................................. Paurocephala

8. On Luehea spp. (Malvaceae) ........................................................................................................................................................................9

- On other plant taxa ..................................................................................................................................................................................... 10

9. Legs bearing sectasetae..................................................................................................................................................................... Klyveria

- Legs lacking sectasetae ..................................................................................................................................................................... Woldaia

10. Antenna with 10 segments; if nine segments then on Asteraceae ..................................................................................... Melanastera

- Antenna with nine segments. Never on Asteraceae ........................................................................ Diclidophlebia and Haplaphalara

Species excluded from Liviidae

Cockerell (1915) described a fragment of a forewing from the Oligocene of the Isle of Wight as † Necropsylla anglica Cockerell, 1915. Bekker-Migdisova (1985) transferred the species provisionally to Camarotoscena based on the long, only weakly curved vein Cu 1a and the straight vein Cu 1b. These characters are not diagnostic for Camarotoscena but occur also in † Lapidopsylla Klimaszewski, 1993 (Aphalaridae, Aphalarinae, †Paleopsylloidini), erected for two species from the Eocene/ Oligocene of the Isle of Wight. † Necropsylla anglica resembles the type species of † Lapidopsylla, † L. thornessbaya Klimaszewski, 1993, with which it appears congeneric. We suggest the following new combination: † Lapidopsylla anglica (Cockerell 1915: 487), comb. nov. from Necropsylla; Camarotoscena, Bekker-Migdisova 1985: 81.

Syntomoza lebezia Hodkinson, 1986 was described from a single specimen from Belize. Hodkinson (1986) placed this species provisionally in Syntomoza as it shares with S. magna the lobed male proctiger and the bulbous apex of the distal portion of the aedeagus, but differs in the head, metatarsi, and terminalia. As the species is morphologically quite distinct, Hodkinson (1986) suggested that it ‘will probably deserve generic status in its own right’. Burckhardt and Mifsud (2003) concluded that the species ‘should be excluded from Syntomoza and the Paurocephalinae’ and suggested some resemblance in the head to Metapsylla Kuwayama, 1908. However, S. lebezia shares with Katacephala (Psyllidae: Katacephalinae) the metatibia lacking a genual spine and bearing a posteriorly open crown of apical spurs, the presence of two basimetatarsal spurs, the posteriorly lobed male proctiger, and the host association with Myrtaceae (unpublished BMNH data). For this reason, we transfer Syntomoza lebezia Hodkinson formally to Katacephala, as Katacephala lebezia (Hodkinson 1986: 149), comb. nov.

The Afrotropical species P. bicarinata Pettey, 1924 and P. hottentotti Pettey, 1933 are currently formally included in Paurocephala. They possess basimetatarsal spurs and are, therefore, not members of the Liviinae (Burckhardt and Mifsud 2003).