Identification key to adult psyllids of Belarus

(Cacopsylla merita and Eryngiofaga deserta are not included in the key as their occurrence in Belarus is unlikely).

1 Vein R+M+Cu of forewing bifurcating into veins R and M+Cu (Fig. 1) 2

– Vein R+M+Cu of forewing trifurcating into veins R, M and Cu. – Triozidae (Fig. 2) 84

2 Metacoxa slender with flattened, tubercular meracanthus. On Acer – Aphalaridae, Rhinocolinae Rhinocola aceris

– Metacoxa massive with distinct, spur-shaped meracanthus 3

3 Vertex longer than wide. Segment 2 the longest antennal segment. On monocots (Carex, Juncus). – Liviidae, Liviinae, Livia 4

– Vertex shorter than wide. Segment 3 the longest antennal segment. On dicots 6

4 Vertex, in dorsal view, forming narrowly rounded anterior lobes with deep median cleft between lobes. Forewing short, oval, with evenly curved anterior margin, bearing indistinct dots in apical half. On Juncus Livia junci

– Vertex, in dorsal view, forming broadly rounded anterior lobes with shallow indentation between lobes. Forewing longer, oblong oval or rhomboidal, in the middle with almost straight anterior margin, pattern different. On Carex 5

5 Forewing with subparallel fore and hind margins, without dark band along apical and anal margin. On Carex Livia crefeldensis

– Forewing widening towards apical third, with broad dark band along apical and anal margin. On Carex Livia limbata

6 Basal spine of metabia always absent; apical metatibial spurs spaced in equal intervals, forming open crown; if grouped, then vertex flattened and rectangular with anterior lobes, or evenly passing into genae 7

– Basal spine of metatibia often developed; apical metatibial spurs always grouped. Head with distinct, though sometimes small, genal processes. – Psyllidae, Psyllinae 37

7 Head bearing genal processes. On Fraxinus – Liviidae, Euphyllurinae, Psyllopsis 8

– Head without genal processes, genae rounded anteriorly 11

8 Body green, forewing lacking dark pattern. Paramere axe-shaped (Fig. 3). Female proctiger distal to circumanal ring abruptly tapered (Fig. 4) Psyllopsis fraxinicola

– Body with dark areas, forewing with dark veins and more or less expanded dark pattern. Male and female terminalia different 9

9 Forewing lacking continuous marginal band apically; membrane dark at apices of veins M and Cu, in the middle of vein Cu_1a and along vein Cu_1b (Fig. 5). Thorax yellow-orange, dark brown dorsally. Paramere, in profile, hammer-shaped with large anteriorly directed lobe (Fig. 6). Apex of female proctiger broad (Fig. 7) Psyllopsis discrepans

– Forewing with dark band along apical margin stretching from fore to hind margin (Figs 8, 11). Thorax yellow with brown or black pattern. Paramere, in profile, with posteriorly directed lobe (Figs 9, 12). Apex of female proctiger narrow (Figs 10, 13) 10

10 Forewing pattern very dark, extended and well-delimited (Fig. 8). Paramere with large rectangular posterior lobe (Fig. 9). Female proctiger with slight hump distal to circumanal ring (Fig. 10) Psyllopsis distinguenda

– Forewing pattern slightly lighter, more reduced, often forming only narrow band, and less clearly delimited towards interior (Fig. 11). Paramere with small triangular posterior lobe (Fig. 12). Female proctiger straight or concave distal to circumanal ring (Fig. 13). Psyllopsis fraxini

11 Metabasitarsus without black spurs. On Populus – Liviidae, Liviinae Camarotoscena speciosa

– Metabasitarsus with 2 black spurs 12

12 Male proctiger without posterior lobes (Fig. 14). ALHW always < 1.0. On Calluna vulgaris. – Liviidae, Euphyllurinae Strophingia ericae

– Male proctiger with long, wing-like posterior lobes. ALHW often > 1.0. – Aphalaridae, Aphalarinae 13

13 Vertex with distinct angular anterior lobes which are separated by narrow transverse groove from genae. Clypeus more or less distinctly protruding from lower head surface. – Aphalara 14

– Vertex with weakly developed anterior lobes, smoothly passing into genae. Clypeus short, pressed against lower head surface, not strongly protruding from genae. – Craspedolepta 24

14 Forewing with dark pattern consisting of well-defined spots or patches. Apical dilatation of aedeagus with large dorso-apical membranous sack. Circumanal ring of female proctiger never expanded caudally 15

– Forewing without well-defined dark pattern but sometimes infuscate. Apical dilatation of aedeagus without or with small dorso-apical membranous sack. Circumanal ring on female proctiger usually expanded caudally (exceptions A. longicaudata, A. purpurascens) 17

15 Clypeus long, clearly visible from above; cylindrical, constricted subapically. Forewing narrow, with dark patches concentrated in apical third, basal half clear. On Polygonum Aphalara maculipennis

– Clypeus short, not or hardly visible from above; conical, apically blunt or subacute. Forewing broad, with dark patches extending also into basal half 16

16 Surface spinules of forewing forming short rows of 2-4 spinules (Fig. 15). Paramere produced apico-posteriorly (Fig. 17). On Rumex Aphalara exilis

– Surface spinules of forewing forming longer rows (Fig. 16). Paramere not produced apico-posteriorly (Fig. 18). On Rumex Aphalara ulicis

17 Head and thorax dark brown or black. On Stellaria graminea Aphalara affinis

– Head and thorax ochreous with orange or brownish markings 18

18 Forewing with surface spinules arranged in irregular, transverse rows (Figs 19, 22-23) 19

– Surface spinules of forewing arranged in irregular squares or rhombi (Figs 24-26) 22

19 Paramere with posterior extension apically (Fig. 20). Female terminalia long (Fig. 21). On Polygonum bistorta Aphalara longicaudata

– Paramere not extented postero-apically. Female terminalia shorter 20

20 Body dimensions large (length from head to apex of forewing when folded over body ≥ 2.9 mm). Forewing membrane amber-coloured, surface spinules arranged in very dense, transverse rows (Fig. 22). On Caltha Aphalara calthae

– Body dimensions small (≤ 3.2 mm). Forewing membrane colourless or fumose, surface spinules arranged in sparse rows (Fig. 23) 21

21 Circumanal ring caudally consisting of several rows of pores. On Polygonum, Rumex Aphalara polygoni

– Circumanal ring caudally consisting of two rows of pores. On Rumex Aphalara purpurascens

22 Male paramere with anterior finger-like process situated subapically (Fig. 27). Aedeagus as in Fig. 28. Female terminalia as in Fig. 29. On Polygonum Aphalara borealis

– Male paramere with anterior finger-like process situated close to apex (Figs 30, 33). Aedeagus as in Figs 31, 34. Female terminalia as in Figs 32, 35 23

23 Tip of distal portion of aedeagus directed in an angle of about 30° to longitudinal axis of segment (Fig. 31). On Polygonum aviculare group Aphalara avicularis

– Tip of distal portion of aedeagus directed in an angle of about 90° to longitudinal axis of segment (Fig. 34). On Polygonum Aphalara freji

24 Forewing with pattern consisting of well-defined, dark spots of 10-30 µm diameter 25

– Forewing without pattern, or with pattern consisting of dark bands, or membrane irregularly infuscate 29

25 Body bearing macroscopic setae which often are covered in wax and thus resemble scales. On Artemisia abrota-num Craspedolepta alevtinae

– Body lacking macroscopic setae 26

26 Forewing with surface spinules completely covering membrane (Fig. 36). Terminalia as in Figs 41-42. On Artemisia Craspedolepta artemisiae

– Forewing with surfaces spinules forming hexagonal pattern (Figs 37-38) 27

27 Forewing with dark spots densely spaced, partly confluent in apical part. On Artemisia campestris Craspedolepta campestrella

– Forewing with dark spots sparsely spaced, not confluent in apical part of wing (Figs 39-40) 28

28 Dark spots on forewing dark brown or almost black; surface spinules relatively sparsely spaced (Fig. 37). Terminalia as in Figs 43-44. On Artemisia vulgaris Craspedolepta latior

– Dark spots on forewing pale to yellow brown; surface spinules relatively dense (Fig. 38). Terminalia as in Figs 45-46. On Artemisia absinthum, A. maritima Craspedolepta malachitica

29 Male paramere with large apical triangular posterior lobe, and subapical anterior process which is very long and directed backwards (Fig. 47). Female proctiger ending in two points (Fig. 48). On Chamerion Craspedolepta subpunctata

– Male paramere, in profile, club-shaped, or if triangular, then anterior process not directed backwards (Figs 50, 53, 57, 61, 63, 65-66). Female proctiger ending in a single point 30

30 Body length from head to apex of forewing when folded over body < 3.2 mm 31

– Body length > 3.5 mm 35

31 Forewing without dark patches or stripes 32

– Forewing with yellow to brown patches or stripes 33

32 Surface spinules of forewing arranged in irregular transverse rows (Fig. 49). Male paramere with large triangular apex and long straight anterior process on inner surface (Fig. 50). Female proctiger more than 4 times longer than pore ring length (Fig. 51). On Daucus Craspedolepta innoxia

– Surface spinules of forewing widely spaced, sometimes partially reduced not forming transverse rows (Fig. 52). Male paramers club-shaped, with short, claw-like anterior process (Fig. 53). Female proctiger less than 4 times as long as pore ring length (Fig. 54). On Artemisia vulgaris Craspedolepta omissa

33 Forewing pattern with dark brown, well-delimited patches forming bands along outer margin and in the middle stretching between the apices of veins R₁ and Cu_1b, and a spot in cell cu₂(Fig. 55). Male proctiger with broad winglike posterior processes lacking a basal hook (Fig. 56). Paramere as in Fig. 57. Female subgenital plate suddenly narrowed subapically (Fig. 58). On Chamerion Craspedolepta nebulosa

– Forewing pattern ochreous to brown, forming bands along the veins in apical half or a band along wing margin. Male proctiger with narrow single-like processes bearing a basal hook. Paramere different, with rounded to angular apical dilatation. Female subgenital plate evenly tapered 34

34 Antenna usually 8-segmented. Forewing pattern distinct, restricted to narrow stripes along veins in apical half (Fig. 59). Terminalia as in Figs 61-62. On Achillea Craspedolepta nervosa

– Antenna usually 10-segmented. Forewing pattern forming a band along outer wing margin (Fig. 60). Terminalia as in Figs 63-64. On Achillea Craspedolepta bulgarica

35 Anterior margin of vertex strongly indented in the middle with two distinct tubercles anteriorly; antero-lateral margin of vertex dorsal of antennal insertion distinctly concave. Forewing yellowish to brownish ochreous. On Leontodon Craspedolepta flavipennis

– Anterior margin of vertex weakly indented in the middle with two indistinct tubercles anteriorly; antero-lateral margin of vertex dorsal of antennal insertion more or less straight. Forewing semitransparent to whitish 36

36 Forewing veins dark brown, membrane light, sometimes with light brownish spots or brownish tinge apically. Paramere stalk robust, apical spoon-like part shorter and rounded as in Fig. 65. Female terminalia as in Fig. 67. On Senecio integrifolius Craspedolepta crispati

– Forewing veins concolorous with membrane, membrane with yellowish tinge and brownish dots in apical third. Paramere stalk slender, apical spoon-like part longer and subangular as in Fig. 66. Female terminalia as in Fig. 68. On Leontodon Craspedolepta sonchi

37 Metabasitarsus with only one outer black spur, rarely also with much smaller inner spur. Propleurites divided by vertical suture 38

– Metabasitarsus with two well-developed black spurs which are subequal in size. Propleurites divided by diagonal suture 44

38 Either genal processes longer than vertex, or length ratio of veins Cu / Cu_1b of forewing 0.9-1.1. Paramere usually slender. – Livilla 39

– Character combination different 41

39 Forewing oval, strongly convex, coriaceous. On Cytisus, Genista Livilla ulicis

– Forewing oblong oval, flat, membranous (Figs 69-70) 40

40 Forewing long and narrow, branches of vein M forming an acute angle, pattern as in Fig. 69. On Genista Livilla horvathi

– Forewing short and broad, branches of vein M forming a right angle, pattern as in Fig. 70. On Chamaecytisus, Cytisus Livilla radiata

41 Forewing broadest in apical third, lacking colour pattern. Paramere very slender, curved caudad, digitiform apically. Dorsal margin of female proctiger, in profile, concave. On Cytisus scoparius Arytainilla spartiophila

– Forewing broadest in the middle or in basal third, with conspicuous brown pattern. Paramere broader, parallel-sided, in profile, truncate apically with large, forward pointing apical tooth. Dorsal margin of female proctiger, in profile, straight. – Arytaina 42

42 Forewing broadest in the middle, fore margin relatively flat. Paramere broad, dorsal margin distinctly concave. On Cytisus, Genista Arytaina genistae

– Forewing broadest in basal third, fore margin strongly curved. Paramere narrow, dorsal margin weakly convex. On Chamaecytisus ratisbonensis Arytaina maculata

43 Antennal segment 9 longer than 10 44

– Antennal segment 9 shorter than 10 48

44 Genal processes short and broad. Forewing with costal break and pterostigma developed; membrane yellow, veins concolorous. Dorsal margin of female proctiger serrate in apical third. On Alnus Baeopelma foersteri

– Character combination different. – Psylla 45

45 Forewing with cell cu₁ almost as high as long; membrane yellowish, veins concolorous, yellow or green. On Buxus Psylla buxi

– Forewing with cell cu₁ at most 1.5 times as long as high. On Betulaceae 46

46 Forewing lacking costal break and pterostigma. On Alnus Psylla fusca

– Forewing bearing costal break and pterostigma 47

47 Genal processes short, rounded. Forewing with dark brown or black veins in apical two thirds. On Alnus Psylla alni

– Genal processes longer, conical. Forewing veins paler. On Betula 48

48 Body length, including forewings when folded over the body, longer than 3.5 mm in males and 4.1 mm in females. Forewing colourless or with yellow tinge. On Betula Psylla betulae

– Body length, including forewings when folded over the body, shorter than 3.7 mm in males and females. Forewing amber-coloured. On Betula Psylla betulaenanae

49 Metatibia with 4 apical spurs. On Betula. Chamaepsylla hartigii

– Metatibia with 5 apical spurs. – Cacopsylla 50

50 Dorsal surface spinules in cell r₂ of forewing above bifurcation of vein M arranged in squares or rhombi of about 20 µm length; surface spinules in cell c+sc restricted to apical portion of cell or entirely reduced; surface spinules reduced in basal part of r₂, at most a few spinules present; fields of surface spinules tapering along apical wing margin; forewing membrane always colourless; pterostigma oblong cuneate, evenly tapering. Antenna shorter than 1.75 mm, if longer, then forewing longer than 3 mm. Male paramere simple, lamellar. Female terminalia short, cuneate 51

– Forewing spinulation different, or wing membrane yellowish or brownish, or pterostigma elongate with subparallel margins. If antenna longer than 1.75 mm, then forewing shorter than 3.0 mm. Male paramere often complex. Female terminalia different 54

51 Antenna shorter than 1.2 mm. On Crataegus Cacopsylla peregrina

– Antenna longer than 1.3 mm 52

52 Antenna longer than 1.75 mm. On Ulmus Cacopsylla ulmi

– Antenna shorter than 1.55 mm 53

53 Antennal segments 4-8 with black apex. On Sorbus Cacopsylla sorbi

– Antennal segments 4-8 with yellow or ochreous apex. On Malus Cacopsylla mali

54 Dorsal surface spinules of forewing in cell r₂ above bifurcation of vein M irregularly, densely spaced (2-10 µm) or arranged in transverse rows 55

– Dorsal surface spinules of forewing forming more or less even squares or rhombi of 20 µm distance in cell r₂ above bifurcation of vein M 62

55 Surface spinules arranged in transverse rows 56

– Surface spinules densely, irregularly spaced 58

56 Paramere, in profile, with large basal lobe. Dorsal margin of female proctiger straight or weakly convex. On Salix Cacopsylla elegantula

– Paramere, in profile, lamellar with anteriorly directed apical tooth. Dorsal margin of female proctiger sinuous. On Salix 57

57 Thorax brown, abdomen green. Terminalia ochreous or brown. On Salix Cacopsylla abdominalis

– Body colour evenly light or reddish. On Salix Cacopsylla intermedia

58 Forewing with an apical dark brown band or completely brown to dark brown 59

– Forewing light, at most yellow or ochreous 60

59 Forewing bearing dark band apically (Fig. 71). Metatibia without genual spine. Male subgenital plate bearing apical tubercular extension (Fig. 72). Female proctiger and subgenital plate ending in thorn-like processes (Fig. 75). On Sorbus Cacopsylla breviantennata

– Forewing irregulary dark without distinct apical ribbon (Fig. 73). Metatibia with genual spine. Male subgenital plate rounded apically (Fig. 74). Female proctiger and subgenital plate evenly tapering in profile (Fig. 76). On Prunus Cacopsylla pruni

60 Forewing bearing ventral surface spinules in cell c+sc. Surface spinules on forewing very densely arranged. On Salix Cacopsylla ambigua

– Ventral surface spinules lacking in cell c+sc. Surface spinules on forewing more sparsely arranged 61

61 Forewing oval, widest in the middle; wing apex near apex of vein M₁₊₂. Antenna shorter than 1.0 mm. On Salix repens and S. rosmarinifolia. Cacopsylla parvipennis

– Forewing widest in apical third; wing apex at the middle of outer margin of cell r₂. Antenna longer than 1.0 mm. On Salix Cacopsylla flori

62 Forewing bearing dark brown patches on tips of veins, at the bifurcation of vein M, and in the middle of vein Cu_1a. On Cercis siliquastrum Cacopsylla pulchella

– Forewing pattern different 63

63 Dorsal surface spinules covering entire cell c+sc of forewing apart from stripes along veins; forming extended fields in other cells which taper towards wing margin; membrane colourless or fumate but never with brown, strongly contrasting stripe along vein Cu_1b 64

– Dorsal surface spinules of forewing more or less reduced, or not tapering towards wing margin, or wing pattern consisting with dark, strongly contrasted stripe along vein Cu_1b 67

64 Antenna usually longer than 1.2 mm. Genal processes broad and blunt. Paramere broad, lanceolate (Fig. 77). Dorsal margin of female proctiger, in profile, weakly sinuous, apex narrowly rounded (Fig. 78). On Pyrus Cacopsylla pyrisuga

– Antenna usually shorter than 1.1 mm. Paramere narrow or with apical processes. Dorsal margin of female proctiger concave in the middle, or apex truncate 65

65 Paramere, in profile, with square base bearing 2 apical processes (Fig. 79). Dorsal margin of female proctiger, distal of circumanal ring, evenly concave; apex rounded (Fig. 80). On Malus Cacopsylla picta

– Paramere, in profile, elongate; apex with inward and forward pointing tooth. Dorsal margin of female proctiger raised in the middle; apex angular 66

66 Paramere long, in profile, narrowed in the middle. Apex of distal segment of aedeagus weakly curved (Fig. 81). On Crataegus Cacopsylla melanoneura

– Paramere short, in profile, evenly tapering from base to apex. Apex of distal segment of aedeagus strongly curved, hook-shaped (Fig. 82). On Crataegus Cacopsylla affinis

67 Forewing with fields of surface spinules tapered along apical wing margin; membrane bearing dark brown patch along vein Cu_1b (Figs 83-84) 68

– Character combination different 69

68 Areas of radular spinules of cells m₁, m₂ and cu₁ of forewing light; dark patch along vein Cu_1b not reaching bifurcation of Cu, not narrowed in proximal half (Fig. 83); surface spinules forming extended fields in cells c+sc and r₁. On Sorbus Cacopsylla albipes

– Areas of radular spinules of cells m₁, m₂ and cu₁ of forewing more or less dark; dark patch along vein Cu_1b reaching bifurcation of Cu, straight in proximal half (Fig. 84); surface spinules reduced in cells c+sc and r₁. On Crataegus Cacopsylla crataegi

69 Surface spinules of forewing forming very narrow fields. On Rhamnus Cacopsylla rhamnicola

– Surface spinules of forewing forming extended fields 70

70 Forewing with fields of surface spinules tapering towards apical margin; clavus with brown apex. 71

– Character combination different 72

71 Paramere sickle-shaped (Fig. 85). Female proctiger strongly narrowed in the middle (Fig. 86). On Pyrus Cacopsylla pyri

– Paramere lamellar (Fig. 87). Female proctiger cuneate (Fig. 88). On Pyrus Cacopsylla pyricola

72 Antenna longer than 1.6 mm 73

– Antenna shorter than 1.3 mm 75

73 Metatibia with 1+1+(2-3)+1 sclerotised apical spurs. Antennal segments 3-7 yellowish or ochreous with dark brown apex. Fields of surface spinules tapering along apical wing margin. On Viscum Cacopsylla visci

– Character combination different 74

74 Body colour dark brown. Paramere with short, angular apical, sclerotised apex (Fig. 89). Valvula 2 of female terminalia with straight ventral margin (Fig. 91). On Hippophae Cacopsylla zetterstedti

– Body colour green or yellow. Paramere with long, curved apical, sclerotised apex (Fig. 90). Valvula 2 of female terminalia with concave ventral margin (Fig. 92) On Hippophae Cacopsylla hippophaes

75 Pterostigma cuneate, broad and short, with converging margins ending in the middle of vein Rs; wing membrane yellowish or ochreous, veins ochreous or light brown 76

– Pterostigma long and narrow, with subparallel margins ending in apical third of vein Rs; wing membrane colourless or dark, veins light or dark 79

76 Fore margin of forewing relatively straight. On Rhododendron. Cacopsylla rhododendri

– Fore margin of forewing strongly curved 77

77 Surface spinules entirely covering cell c+sc of forewing. On Vaccinium Cacopsylla myrtilli

– Surface spinules absent from basal third of cell c+sc of forewing 78

78 On Vaccinium myrtillus Cacopsylla fraudatrix

– On Ledum palustre Cacopsylla ledi

79 Male paramere bearing subapical lobe along hind margin 80

– Male paramere lacking subapical lobe along hind margin 82

80 Paramere lacking basal lobe at hind margin. On Salix. Cacopsylla moscovita

– Paramere bearing basal lobe at hind margin 81

81 Basal lobe at hind margin of paramere not incised dorsally. On Salix. Cacopsylla saliceti

– Basal lobe at hind margin of paramere strongly incised dorsally. On Salix Cacopsylla iteophila

82 Apex of paramere forming simple, backwards directed sclerotised tooth. On Salix Cacopsylla pulchra

– Apex of paramere with two strongly sclerotised teeth 83

83 Paramere, in rear view, with a tooth in apical third; in profile, as in Fig. 93. On Salix Cacopsylla brunneipennis

– Paramere, in rear view, with lobe in the middle of inner margin; in profile, as in Fig. 94. On Salix Cacopsylla nigrita

84 Metatibia with 1+3 sclerotised apical spurs 85

– Metatibia with 1+2 sclerotised apical spurs 107

85 Forewing with extended dark pattern consisting of small points; fore margin straight to concave between apices of veins Rs and M₁₊₂ (Fig. 95). On Rhamnus cathartica Trichochermes walkeri

– Forewing pattern different; fore margin convex. – Trioza p.p 86

86 Forewing short and broad, angular apically; branching of vein M distinctly distal to Rs–Cu_1a line. Antennal colour strongly contrasted, segment 3 light, segments 4-10 dark 87

– Forewing elongate, sometimes rounded apically; Rs–Cu_1a line proximal to or on branching of vein M. Antennal colour variable. 89

87 Genal processes short. Paramere, in profile, strongly narrowed in apical quarter, forming anterior tubercle and posterior process (Fig. 96). Female subgenital plate truncate apically, consequently strongly convex dorsally (Fig. 97). Terminal setae on antennal segment 10 subequal. On Valerianella Trioza centranthi

– Genal processes long. Male paramere in apical quarter regularly narrowing to apex (Figs 98, 100). Female subgenital plate evenly tapering to apex, dorsal margin almost straight (Figs 99, 101). Terminal setae on antennal segment 10 strongly unequal. 88

88 Forewing without surface spinules. Male paramere robust, angular apically; distal portion of aedeagus with large apical hook (Fig. 98); female subgenital plate, in profile, with obtuse apex (Fig. 99). On Galium and other Rubia-ceae Trioza galii

– Forewing with surface spinules. Male paramere slender, curved apically (Fig. 100); female subgenital plate, in profile, with small sharp tooth at apex (Fig. 101). On Galium Trioza velutina

89 Forewing with surface spinules present at most in cell cu₂. Male paramere long and slender, lamellar (Fig. 102). Female terminalia long, dorsal margin of proctiger more or less straight (Fig. 103). On Urtica Trioza urticae

– Forewing with surface spinules present in all cells, covering smaller or larger areas 90

90 Terminal antennal setae strongly differing in length, both distinctly shorter than antennal segment 10; shorter seta very short, stout and truncate apically. Axes of genal processes diverging forward; genal processes relatively massive and blunt, evenly narrowed. Body orange to reddish, sometimes brownish to black 91

– Terminal antennal setae different; axes of genal processes parallel, or genal processes slender and pointed or fusi-form, or body yellowish or greenish 94

91 Surface spinules of forewing spaced at 5-10 µm intervals or forming transverse rows in the middle of cell r₂ at level of branching of vein M, never reduced along outer wing margin. Male paramere basally robust (Fig. 104), female terminalia short with proctiger, in profile, dorsally straight (Fig. 105). On Hieracium Trioza proxima

– Surface spinules of forewing forming regular rectangles or rhombes of 15-10 µm distance, sometimes reduced along outer wing margin. Terminalia different 92

92 Male paramere with weak subapical constriction. Female proctiger cuneate, regularly tapering to apex, short, about twice as long as circumanal ring. On Mycelis Trioza foersteri

– Male paramere with strong subapical constriction (Fig. 106, 108). Female terminalia different 93

93 Male paramere about as long as or longer than proctiger, apical portion bent inwards and weakly backwards (Fig. 106). FPHW less than 0.8, proctiger truncate apically (Fig. 107). On Taraxacum Trioza dispar

– Male paramere shorter than proctiger or apical portion straight, directed upwards (Fig. 108). FPHW more than 0.8, proctiger regularly narrowed apically (Fig. 109). On Hieracium Trioza tatrensis

94 Surface spinules of forewing in cell r₂ at level of branching of vein M densely spaced in a distance of 6-12 µm 95

– Surface spinules of forewing in cell r₂ at level of branching of vein M arranged in regular rectangles or rhombi in a distance of 10-20 µm 97

95 Forewing distinctly angular apically; vein Cu much more than twice as long as Cu_1b, cell cu₁ flat. Male paramere slender in apical half; apex turned backwards. Female proctiger blunt apically. On Aegopodium Trioza flavipennis

– Forewing irregularly rounded apically; vein Cu at most slightly more than twice as long as Cu_1b, cell cu₁ high. Male paramere massive in apical half; apex turned inwards or forwards (Fig. 110). Female proctiger pointed apically (Fig. 111) 96

96 Male parameres with large antero-basal lobe. Distal aedeagal segment with large apical hook. Female subgenital plate short, truncate apically. Lateral abdominal setae present on tergites 3 and 4 in males, and 4 and 5 in females. Relative lengths of terminal antennal segment: shorter terminal antennal seta: longer terminal antennal seta = 1.0: 0.4: 0.7. On Cardamine, Stellaria Trioza rotundata

– Male parameres without distinct antero-basal lobe. Distal aedeagal segment with short hook. Female subgenital plate long, pointed apically. Lateral abdominal setae present on tergites 3 in males, 4 in females. Relative lengths of terminal antennal segment: shorter terminal antennal seta: longer terminal antennal seta = 1.0: 0.3: 0.8. On Valerianella tripteridis Trioza tripteridis

97 Forewing with very long, sinuous vein Rs; membrane transparent, colourless, wing margin with dark dots at intersections of veins and near radular spinules. One terminal antennal seta less than three times shorter than the other seta. On Rhamnus Trioza rhamni

– Combination of characters different 98

98 Body almost completely dark brown or black 99

– Body green, yellow or reddish; sometimes thorax dark but abdomen green 100

99 Forewing membrane dirty whitish. Apex of paramere pointing forwards. Female proctiger truncate apically. On Saxifraga Trioza saxifragae

– Forewing membrane ochreous. Apex of paramere pointing backwards. Female proctiger subacute apically. On Astrantia major Trioza schrankii

100 Body straw-coloured or ochreous. Paramere simple, broadly lamellar. Female proctiger short, about twice as long as circumanal ring. On Rumex scutatus Trioza rumicis

– Body green, light yellow, sometimes thorax brown. Paramere with inner process or with broad base and narrow apical portion. Female proctiger about three times as long as circumanal ring 101

101 Forewing broadly irregularly rounded apically. Male proctiger with posterior lobe; paramere with inner process (Fig. 112). On Cerastium Trioza cerastii

– Forewing angular apically. Male proctiger without posterior lobe; paramere without inner process 102

102 Body always, also in overwintered specimens, yellow or green, never yellowish orange, or with brown to black spots 103

– Body never exclusively yellow or green; either yellow-orange or with brown to black spots 105

103 Antennal segments 6-8 brown. Basal portion of male paramere with distinct antero-apical tubercle (Fig. 113). Female proctiger, in profile, with weakly sinuous dorsal margin (Fig. 114). On Cirsium Trioza cirsii

– Antennal segments 6-8 light. Male and female terminalia different 104

104 Basal portion of male paramere angled antero-apically. Female terminalia long. On Cirsium Trioza agrophila

– Basal portion of male paramere oblique antero-apically. Female terminalia short. On Senecio Trioza senecionis

105 Postero-apical process of paramere very slender and straight. Female subgenital plate much shorter than proctiger. On Chrysanthemum Trioza chrysanthemi

– Postero-apical process of paramere wider and curved. Female subgenital plate about as long as proctiger 106

106 Paramere with very small anterior lobe (Fig. 115). Female subgenital plate slender apically. On Achillea Trioza abdominalis

– Paramere with large anterior lobe. Female subgenital plate massive apically. On Knautia Trioza munda

107 Branching of vein M of forewing distinctly distal to Rs–Cu_1a line; vein Rs straight or concavely curved to fore margin; forewing angular apically 108

– Branching of vein M of forewing proximal to or about on Rs–Cu_1a line, or vein Rs sinuate, or apex of forewing broadly rounded 110

108 Genal processes short. Forewing very narrow with low cell cu₁; surface spinules absent. Male paramere narrow (Fig. 116); female terminalia as in Fig. 117. On Laurus Trioza alacris

– Genal processes longer. Forewing broader; cell cu₁ higher; surface spinules present or absent. Male paramere broad, female terminalia different 109

109 Large species, forewing longer than 2.65 mm. Surface spinules of forewing always present. Terminalia as in Figs 118-119. On Quercus Trioza remota

– Small species, forewing shorter than 2.6 mm. Surface spinules present or absent. Terminalia different. On Amaran-thaceae Trioza chenopodii

110 Body green or yellow 111

– Body colour different 113

111 Antennal segments 4-6 yellow or light ochreous; apical two or three dark segments strongly contrasting with the lighter more basal segments. On Apiaceae Trioza apicalis

– Antennal segments 4-6 dark ochreous or light brown; antennal segments gradually becoming darker from segment 3 to apex 112

112 Paramere with short dorsal projection and narrow anterior lobe (Fig. 120). Female subgenital plate with terminal process forming a long parallel sided projection (Fig. 121). On Anthriscus and other Apiaceae Trioza anthrisci

– Paramere with long dorsal projection and narrow anterior lobe (Fig. 122). Female subgenital plate with short and regularly tapering terminal process (Fig. 123). On Laserpitium Trioza laserpitii

113 Surface spinules present in distal cells of forewing 114

– Surface spinules absent or present at most in cell cu 120

114 Surface spinules absent from cell r₁ of forewing Bactericera maura

– Surface spinules present in cell r₁ of forewing 115

115 Antennal segments 4-7 dark 116

– Antennal segments 4-7 light 117

116 Surface spinules entirely covering cell r_l of forewing. Abdominal venter whitish, distinctly lighter than dorsum. Male paramere, in profile, sinuous with wide base and slender apex (Fig. 124). Ventral margin of female subgenital plate straight or concave subapically. On Salix Bactericera albiventris

– Surface spinules of forewing present only in basal half of cell r_l. Abdominal venter not whitish, or the same colour as dorsum. Male paramere, in profile, straight, with mostly subparal margins (Fig. 125). Ventral margin of female subgenital plate straight or convex subapically. On Salix. Bactericera salicivora

117 Surface spinules in apical half of forewing covering the whole surface up to the veins; wing angular apically (Fig. 2). Terminalia as in Figs 126-127. On Comarum palustre Bactericera acutipennis

– Surface spinules leaving spinule-free stripes along veins of forewing 118

118 Antennal segments 4 and 6 with each a group of rhinaria, therefore strongly dilated apically. Terminalia as in Figs 128-129. On Alchemilla Bactericera femoralis

– Antennal segments 4 and 6 with each 1 rhinarium, not strongly dilated apically 119

119 Surface spinules of forewing also present in distal half of cell r₁ and entirely covering cell c+sc. On Potentilla anserina Bactericera reuteri

– Surface spinules of forewing present only in proximal half of cell r₁ and strongly reduced in cell c+sc. On Geum Bactericera bohemica

120 Genal processes at most as long as two thirds of vertex. Antenna entirely dark brown to black. Terminalia as in Figs 130-131. Polyphagous on dicotyledonous herbs Bactericera nigricornis

– Genal processes about as long as vertex. At least antennal segment 3 light 121

121 Antenna completely black. On Artemisia Bactericera calcarata

– At least antennal segment 3 light 122

122 Antennal segments 3-5 partly or entirely light. On Sanguisorba Bactericera modesta

– Antennal segment 3 light, 4 and 5 dark 123

123 Forewing widest in the middle. On Berberis vulgaris Trioza scottii

– Forewing widest in apical thirds. On Salix 124

124 Forewing with vein A entirely dark Bactericera curvatinervis

– Dark colour on vein A of forewing reduced to a spot 125

125 Dark spot on vein A of forewing distinct. Male paramere, in profile, more or less straight with large anteriorly directed tooth (Fig. 132). Female proctiger short with apical two thirds of dorsal outline strongly convex Bactericera striola

– Dark spot on vein A of forewing indistinct. Male paramere sickle-shaped or with small apical hook. Female proctiger longer with apical two thirds of dorsal outline straight or concave 126

126 Male parameres, in profile, sickle-shaped. Female subgenital plate long with indistinct, long apical process Bactericera substriola

– Male parameres, in profile, straight, lamellar, with small apical tooth. Female subgenital plate short with distinct short apical process Bactericera parastriola