British insects: the families of Coleoptera

L. Watson and M. J. Dallwitz

Conventional key

If you are serious about identification, you should use the interactive key. It is far superior, with flexible choice of characters, character notes and illustrations, error tolerance, full taxon descriptions, and taxon illustrations.

1(0).

Antennae filiform ... 2 Antennae gradually expanding towards the apex... 57 Antennae clubbed... 74 Antennae serrate... 169 Antennae pectinate... 179

2(1).

water-beetles ... 3 land-dwellers... 7

3(2).

Hind coxae much expanded and extended laterally to meet the elytra ... 4 Hind coxae not extended laterally to meet the elytra... 6

4(3).

Hind coxae produced behind into flat plates which conceal the hind femora when retracted; compound eyes coarsely facetted; antennal insertions visible from above ... Haliplidae Hind coxae not concealing the hind femora; compound eyes finely facetted; antennal insertions hidden from above... 5

5(4).

The beetle with a conspicuous flat, ventral longitudinal keel representing fusion of the distinct inner parts of the extended hind coxa with one another and with the metasternum ... Noteridae The beetle without a conspicuous, flat ventral keel ... Dytiscidae

6(3).

Hind coxae posteriorly shaped to receive the retracted femur; hind tarsi not modified for swimming; compound eyes not strongly protuberant; the maxillae without a conspicuous galea; antennae short ... Elmidae Hind coxae not shaped posteriorly to receive the femur; hind tarsi modified for swimming, with an oar-like arrangement of hairs; compound eyes strongly protuberant; the maxillae with an outer palpiform lobe (the galea) additional to the 4-segmented maxillary palp; antennae very short ... Hygrobiidae

7(2).

Beetles equipped with a rostrum ... 8 Beetles without a rostrum... 9

8(7).

Apparent tarsal segmentation 5, 5, 4; the tarsi without bilobed segments; the tarsi without ‘hidden’ segments ... Salpingidae Apparent tarsal segmentation 4, 4, 4; the tarsi exhibiting bilobed segments; the tarsi with a tiny penultimate segment hidden by distal lobing of the fourth and fused to the fifth ... Anthribidae

9(7).

Hind coxae posteriorly shaped to receive the retracted femur ... 10 Hind coxae not shaped posteriorly to receive the femur... 15

10(9).

Antennal scape swollen ... Scirtidae Antennal scape not swollen... 11

11(10).

Beetles clicking and ‘jumping’ to right themselves when inverted ... Elateridae Beetles not clicking and ‘jumping’... 12

12(11).

Metaventrite with a transverse groove; the tarsi exhibiting bilobed segments ... 13 Metaventrite without a transverse groove; the tarsi without bilobed segments... 14

13(12).

Beetles somewhat waisted ... Dascillidae Beetles conspicuously waisted ... Buprestidae

14(12).

The head covered by the thorax; exposed abdominal sternites comprising both fused and movable components ... Anobiidae The head not covered by the thorax; exposed abdominal sternites all fused and immovable ... Eucnemidae

15(9).

Elytra present ... 16 Elytra absent... 56

16(15).

Hind tarsi with as many segments as the mid-tarsi ... 17 Hind tarsi with one segment fewer than the mid-tarsi... 43

17(16).

The head covered by the thorax ... 18 The head not covered by the thorax... 19

18(17).

Compound eyes finely facetted; elytra not meeting along the full length of the mid-line; exposed abdominal sternites all articulated and movable; the claws of the mid-leg tarsi without an associated empodium ... Lampyridae (males) Compound eyes coarsely facetted; elytra meeting along the length of the mid-line; exposed abdominal sternites comprising both fused and movable components; the claws of the mid-leg tarsi with an empodium between them ... Eucinetidae

19(17).

Prothorax with notopleural sutures; hind coxae immovably fixed to the metasternum and dividing the first abdominal sternite ... 20 Prothorax without notopleural sutures; hind coxae movable... 21

20(19).

The maxillae with an outer palpiform lobe (the galea) additional to the 4-segmented maxillary palp; elytra striate ... Carabidae The maxillae without a conspicuous galea; elytra without striae ... Cicindelidae

21(19).

Exposed abdominal sternites 3 to 4 ... 22 Exposed abdominal sternites 5... 23 Exposed abdominal sternites 6 to 7... 31 Exposed abdominal sternites 8 or more... 42

22(21).

Beetles conspicuously necked; compound eyes accommodating the antennae in an anterior notch; larvae in rotting wood ... Aderidae Beetles not necked; compound eyes not accommodating the antennae in a notch; larvae on living vegetation ... Chrysomelidae

23(21).

Compound eyes accommodating the antennae in an anterior notch ... 24 Compound eyes not accommodating the antennae in a notch... 26

24(23).

Exposed abdominal sternites all articulated and movable ... 25 Exposed abdominal sternites comprising both fused and movable components ... Aderidae

25(24).

Elytra truncate ... Bruchidae Elytra not truncate ... Cerambycidae

26(23).

Elytra meeting along the length of the mid-line; elytra covering most to all of the abdomen ... 27 Elytra not meeting along the full length of the mid-line; elytra short, exposing several terminal abdominal tergites ... Lymexylidae

27(26).

The tarsi with a tiny penultimate segment hidden by distal lobing of the fourth and fused to the fifth ... Chrysomelidae The tarsi with a tiny basal segment that is hard to detect ... Cucujidae The tarsi without ‘hidden’ segments... 28

28(27).

Hind tarsi 4-segmented ... 29 Hind tarsi 5-segmented... 30

29(28).

Fore coxal cavites closed behind ... Salpingidae Fore coxal cavites open behind ... Cucujidae

30(28).

Exposed abdominal sternites all articulated and movable; adults predacious ... Cucujidae Exposed abdominal sternites comprising both fused and movable components; adults not predacious ... Ptinidae

31(21).

The tarsi exhibiting bilobed segments ... 32 The tarsi without bilobed segments... 34

32(31).

Abdominal segment 8 with apparently functional spiracles ... 33 Abdominal segment 8 apparently without functional spiracles ... Melyridae

33(32).

Antennal insertions visible from above; compound eyes present; adult body length/maximum body width 2 to 7; adults in living vegetation ... Cantharidae Antennal insertions hidden from above; compound eyes absent; adult body length/maximum body width up to 2; adults on shed fur or feathers ... Leptinidae

34(31).

Antennae with the scape much-elongated ... Staphylinidae Antennae without a much-elongated scape... 35

35(34).

Abdominal segment 8 with apparently functional spiracles ... 36 Abdominal segment 8 apparently without functional spiracles... 38

36(35).

Beetles conspicuously necked ... Scydmaenidae Beetles not necked... 37

37(36).

Beetles exhibiting bright ‘warning colours’; compound eyes strongly protuberant; adults predacious; larvae predacious ... Lycidae Beetles without ‘warning colouration’; compound eyes not strongly protuberant; adults not predacious; larvae not predacious ... Scaphidiidae

38(35).

Elytra meeting along the length of the mid-line ... 39 Elytra not meeting along the full length of the mid-line ... Lymexylidae

39(38).

Beetles conspicuously necked ... 40 Beetles not necked... 41

40(39).

Adults in living vegetation ... Melyridae Adults in decaying plant material ... Scydmaenidae Adults in rotting wood ... Scydmaenidae Adults under bark ... Scydmaenidae Adults under stones ... Scydmaenidae

41(39).

Beetles dorsally flattened ... Melyridae Beetles dorsally strongly convex ... Scaphidiidae Beetles cylindric ... Scaphidiidae

42(21).

Beetles exhibiting bright ‘warning colours’; the tarsi without bilobed segments; elytra ribbed ... Lycidae Beetles without ‘warning colouration’; the tarsi exhibiting bilobed segments; elytra smooth ... Cantharidae

43(16).

Elytra meeting along the length of the mid-line ... 44 Elytra not meeting along the full length of the mid-line... 55

44(43).

Elytra iridescent ... Pythidae Elytra not iridescent... 45

45(44).

Exposed abdominal sternites all articulated and movable ... 46 Exposed abdominal sternites comprising both fused and movable components... 51 Exposed abdominal sternites all fused and immovable ... Anthicidae

46(45).

Beetles conspicuously necked ... 47 Beetles not necked... 49

47(46).

The tarsi exhibiting bilobed segments ... Scraptiidae The tarsi without bilobed segments... 48

48(47).

Antennae with the scape much-elongated; the claws of the mid-leg tarsi simple; elytra short, exposing several terminal abdominal tergites; exposed abdominal sternites 6 to 7; elytra exposing at least three complete abdominal tergites ... Staphylinidae Antennae without a much-elongated scape; the claws of the mid-leg tarsi serrate, denticulate or pectinate; elytra covering most to all of the abdomen; exposed abdominal sternites 5; elytra exposing at least one but fewer than three complete abdominal tergites ... Mordellidae

49(46).

Elytra individually distinctly tapered to their apices; beetles not prognathous ... Melandryidae Elytra not individually tapered; beetles prognathous... 50

50(49).

Fore coxal cavites closed behind ... Salpingidae Fore coxal cavites open behind ... Cucujidae

51(45).

Apparent tarsal segmentation 5, 5, 5 ... Ptinidae Apparent tarsal segmentation 5, 5, 4... 52 Apparent tarsal segmentation 4, 4, 4... 54 Apparent tarsal segmentation 4, 4, 3 ... Aderidae

52(51).

Elytra individually distinctly tapered to their apices ... Melandryidae Elytra not individually tapered... 53

53(52).

Elytra glossy; exposed abdominal sternites immovably joined 2; fore coxal cavites closed behind ... Salpingidae Elytra dull; exposed abdominal sternites immovably joined 3 to 4; fore coxal cavites open behind ... Tenebrionidae

54(51).

Beetles conspicuously necked; compound eyes accommodating the antennae in an anterior notch; the tarsi with a tiny penultimate segment hidden by distal lobing of the fourth and fused to the fifth; mid-leg tarsi with 4 obvious segments, plus a reduced penultimate one; elytra not individually tapered ... Aderidae Beetles not necked; compound eyes not accommodating the antennae in a notch; the tarsi without ‘hidden’ segments; mid-leg tarsi with 5 segments, all conspicuous; elytra individually distinctly tapered to their apices ... Melandryidae

55(43).

Beetles conspicuously necked; the tarsi without bilobed segments; exposed abdominal sternites all articulated and movable; prothorax shorter than wide; larvae predacious ... Meloïdae Beetles not necked; the tarsi exhibiting bilobed segments; exposed abdominal sternites comprising both fused and movable components; prothorax longer than wide; larvae not predacious ... Oedemeridae

56(15).

The head covered by the thorax; beetles luminescent from distal abdominal sternites; adults not predacious ... Lampyridae (females) The head not covered by the thorax; beetles not luminescent; adults predacious... Drilidae (females)

57(1).

Beetles equipped with a rostrum ... 58 Beetles without a rostrum... 59

58(57).

Beetles exhibiting bright ‘warning colours’; apparent tarsal segmentation 4, 4, 4; the tarsi exhibiting bilobed segments; the tarsi with a tiny penultimate segment hidden by distal lobing of the fourth and fused to the fifth ... Nemonychidae Beetles without ‘warning colouration’; apparent tarsal segmentation 5, 5, 4; the tarsi without bilobed segments; the tarsi without ‘hidden’ segments ... Salpingidae

59(57).

Hind coxae posteriorly shaped to receive the retracted femur ... Byrrhidae Hind coxae not shaped posteriorly to receive the femur... 60

60(59).

Hind tarsi with as many segments as the mid-tarsi ... 61 Hind tarsi with one segment fewer than the mid-tarsi... 69

61(60).

Abdominal segment 8 with apparently functional spiracles ... 62 Abdominal segment 8 apparently without functional spiracles... 63

62(61).

Apparent tarsal segmentation 5, 5, 5; the tarsi without ‘hidden’ segments; elytra truncate; antennae strongly asymmetric; mid-leg tarsi with 5 segments, all conspicuous ... Silphidae Apparent tarsal segmentation 4, 4, 4; the tarsi with a tiny penultimate segment hidden by distal lobing of the fourth and fused to the fifth; elytra not truncate; antennae not strongly asymmetric; mid-leg tarsi with 4 obvious segments, plus a reduced penultimate one ... Chrysomelidae

63(61).

The tarsi with a tiny penultimate segment hidden by distal lobing of the fourth and fused to the fifth ... 64 The tarsi with a tiny basal segment that is hard to detect... 65 The tarsi without ‘hidden’ segments... 66

64(63).

Mid-leg tarsi with 4 obvious segments, plus a reduced penultimate one; larvae phytophagous; adults phytophagous ... Chrysomelidae Mid-leg tarsi with 3 obvious segments plus a reduced penultimate one; larvae mycetophagous; adults mycetophagous ... Endomychidae

65(63).

Adults 1.5 to 5 mm long; adults not predacious; larvae not predacious ... Silvanidae Adults 5.1 to 20 mm long; adults predacious; larvae predacious ... Cleridae

66(63).

Beetles not waisted ... Mycetophagidae Beetles somewhat waisted ... Mycetophagidae Beetles conspicuously waisted... 67

67(66).

Adults 1.5 to 5 mm long ... 68 Adults 5.1 to 20 mm long ... Cleridae

68(67).

Apparent tarsal segmentation 5, 5, 4; the tarsi without bilobed segments ... Salpingidae Apparent tarsal segmentation 4, 4, 4; the tarsi exhibiting bilobed segments ... Silvanidae

69(60).

The end of the abdomen extended as a long, narrow point beyond the ends of the truncate elytra ... Mordellidae The end of the abdomen not extended as a long, narrow point beyond the ends of the elytra... 70

70(69).

Elytra individually distinctly tapered to their apices ... Melandryidae Elytra not individually tapered... 71

71(70).

The tarsi exhibiting bilobed segments ... 72 The tarsi without bilobed segments... 73

72(71).

Adults 1.5 to 5 mm long; exposed abdominal sternites all fused and immovable; adults not predacious; larvae not predacious ... Anthicidae Adults 5.1 to 20 mm long; exposed abdominal sternites all articulated and movable; adults predacious; larvae predacious ... Cleridae

73(71).

Elytra glossy; fore coxal cavites closed behind ... Salpingidae Elytra dull; fore coxal cavites open behind ... Tenebrionidae

74(1).

Beetles equipped with a rostrum ... 75 Beetles without a rostrum... 78

75(74).

Beetles conspicuously necked ... Attelabidae Beetles not necked... 76

76(75).

Antennae conspicuously elbowed; antennae with the scape much-elongated ... Curculionidae Antennae not elbowed; antennae without a much-elongated scape... 77

77(76).

The maxillary palps normal, flexible; exposed abdominal sternites immovably joined 3 to 4 ... Anthribidae The maxillary palps if visible, short and rigid; exposed abdominal sternites immovably joined 2 ... Apionidae

78(74).

water-beetles ... 79 land-dwellers... 83

79(78).

Antennal scape swollen; hind coxae produced behind into flat plates which conceal the hind femora when retracted; hind coxae posteriorly shaped to receive the retracted femur ... Sphaeriidae Antennal scape not swollen; hind coxae not concealing the hind femora; hind coxae not shaped posteriorly to receive the femur... 80

80(79).

Hind coxae much expanded and extended laterally to meet the elytra; aquatic beetles ‘rowing’ by parallel-simultaneous leg movements; the maxillae with an outer palpiform lobe (the galea) additional to the 4-segmented maxillary palp; compound eyes ostensibly four; prothorax with notopleural sutures ... Gyrinidae Hind coxae not extended laterally to meet the elytra; aquatic beetles moving in the water by alternate, walking leg movements; the maxillae without a conspicuous galea; compound eyes two; prothorax without notopleural sutures... 81

81(80).

Apparent tarsal segmentation 5, 5, 5 ... 82 Apparent tarsal segmentation 4, 4, 4 ... Hydraenidae

82(81).

The claws of the mid-leg tarsi with an empodium between them; the maxillary palps conspicuously elongated, often longer than the antennae; hind coxae without the steep transverse declivity characteristic of Dryopoidea; larvae predacious ... Hydrophilidae The claws of the mid-leg tarsi without an associated empodium; the maxillary palps not especially elongated; hind coxae with a steep transverse declivity against which the femur retracts; larvae not predacious ... Dryopidae

83(78).

Antennal scape swollen ... 84 Antennal scape not swollen... 89

84(83).

The tarsi exhibiting bilobed segments ... 85 The tarsi without bilobed segments... 87

85(84).

Elytral epipleura reaching to the tips of the elytra ... Phalacridae Elytral epipleura falling short of the elytral tips... 86

86(85).

Beetles oval ... Nitidulidae Beetles elongate-oval ... Cryptophagidae Beetles elongate ... Cryptophagidae

87(84).

The head covered by the thorax; elytra without striae ... Corylophidae The head not covered by the thorax; elytra striate... 88

88(87).

Antennal clubs spherical, comprising two small basal segments and a large terminal one; fore coxal cavites open behind ... Cerylonidae Antennal clubs not comprising two small basal segments and a large terminal one; fore coxal cavites closed behind ... Mycetophagidae

89(83).

Hind coxae posteriorly shaped to receive the retracted femur ... 90 Hind coxae not shaped posteriorly to receive the femur... 97

90(89).

Hind coxae produced behind into flat plates which conceal the hind femora when retracted ... Ptiliidae Hind coxae not concealing the hind femora... 91

91(90).

Mid-leg tarsi with 5 segments, all conspicuous; front tarsi 5-segmented; mid-leg tarsi 5-segmented; hind tarsi 5-segmented ... 92 Mid-leg tarsi with 4 segments, all easily seen; front tarsi 4-segmented; mid-leg tarsi 4-segmented; hind tarsi 4-segmented... 96

92(91).

Mandibular prosthecae well developed ... 93 Mandibular prosthecae present but reduced ... Throscidae Mandibular prosthecae absent... 94

93(92).

Antennal clubs preceded by a cupule; hind coxae without the steep transverse declivity characteristic of Dryopoidea ... Nosodendridae Antennal clubs without a cupule; hind coxae with a steep transverse declivity against which the femur retracts ... Limnichidae

94(92).

Metaventrite with a transverse groove; the tarsi exhibiting bilobed segments ... Buprestidae Metaventrite without a transverse groove; the tarsi without bilobed segments... 95

95(94).

The head covered by the thorax ... Anobiidae The head not covered by the thorax ... Throscidae

96(91).

Beetles not waisted; compound eyes coarsely facetted; antennae short; antennae not strongly asymmetric; metaventrite without a transverse groove ... Clambidae Beetles conspicuously waisted; compound eyes finely facetted; antennae very short; antennae strongly asymmetric; metaventrite with a transverse groove ... Heteroceridae

97(89).

Abdominal segment 8 with apparently functional spiracles ... 98 Abdominal segment 8 apparently without functional spiracles... 114

98(97).

Antennae strongly asymmetric ... 99 Antennae not strongly asymmetric... 102

99(98).

Antennae with the scape much-elongated ... Lucanidae Antennae without a much-elongated scape... 100

100(99).

Antennal clubs lamellate ... 101 Antennal clubs not lamellate ... Silphidae

101(100).

Antennae 5 to 8 segmented ... Scarabaeidae Antennae 9 to 10 segmented ... Scarabaeidae Antennae 11 segmented ... Geotrupidae

102(98).

The head covered by the thorax; prothorax hooded and concealing the head, its front covered with large bumps ... Bostrychidae The head not covered by the thorax; prothorax not hooded with anterior bumps... 103

103(102).

Beetles conspicuously necked ... 104 Beetles not necked... 106

104(103).

Antennae with the scape much-elongated ... Staphylinidae Antennae without a much-elongated scape... 105

105(104).

Mid-leg tarsi 3-segmented; mid-leg tarsi with 3 segments, all easily seen; hind tarsi 3-segmented; elytra short, exposing several terminal abdominal tergites; elytra truncate ... Pselaphidae Mid-leg tarsi 5-segmented; mid-leg tarsi with 5 segments, all conspicuous; hind tarsi 5-segmented; elytra covering most to all of the abdomen; elytra not truncate ... Scydmaenidae

106(103).

Antennal clubs lamellate ... Trogidae Antennal clubs not lamellate... 107

107(106).

Antennal segment 8 smaller than segments 7 and 9 ... Leiodidae Antennal segment 8 not smaller than 7 and 9... 108

108(107).

Scutellary striole present ... 109 Scutellary striole absent... 110

109(108).

Compound eyes strongly protuberant; the maxillary palps not especially elongated; antennae short; beetles conspicuously waisted; larvae not predacious ... Lyctidae Compound eyes not strongly protuberant; the maxillary palps conspicuously elongated, often longer than the antennae; antennae very short; beetles somewhat waisted; larvae predacious ... Hydrophilidae

110(108).

Beetles exhibiting bright ‘warning colours’; adults predacious ... Lycidae Beetles without ‘warning colouration’; adults not predacious... 111

111(110).

The maxillary palps conspicuously elongated, often longer than the antennae; larvae predacious ... Hydrophilidae The maxillary palps not especially elongated; larvae not predacious... 112

112(111).

Mid-leg tarsi with 5 segments, all conspicuous; hind coxae without the steep transverse declivity characteristic of Dryopoidea ... 113 Mid-leg tarsi with 4 segments, all easily seen; hind coxae with a steep transverse declivity against which the femur retracts ... Dryopidae

113(112).

Elytra truncate; exposed abdominal sternites 6 to 7; larvae mycetophagous ... Scaphidiidae Elytra not truncate; exposed abdominal sternites 5; larvae feeding on dried animal remains ... Dermestidae

114(97).

Hind tarsi with as many segments as the mid-tarsi ... 115 Hind tarsi with one segment fewer than the mid-tarsi... 157

115(114).

The tarsi exhibiting bilobed segments ... 116 The tarsi without bilobed segments... 126

116(115).

Antennae conspicuously elbowed; antennae with the scape much-elongated ... Scolytidae Antennae not elbowed; antennae without a much-elongated scape... 117

117(116).

Beetles terrapin-like in shape, with flattened and clear margins to thorax and elytra ... Peltidae Beetles not terrapin-like in shape, and without flattened and clear margins to both thorax and elytra... 118

118(117).

Prothorax shorter than wide ... 119 Prothorax about as long as wide... 123 Prothorax longer than wide... 124

119(118).

The claws of the mid-leg tarsi simple ... 120 The claws of the mid-leg tarsi one-toothed or bifid... 122

120(119).

Elytral epipleura reaching to the tips of the elytra ... 121 Elytral epipleura falling short of the elytral tips ... Cryptophagidae

121(120).

Front tarsi 4-segmented; mid-leg tarsi 4-segmented; fore coxal cavites closed behind ... Endomychidae Front tarsi 5-segmented; mid-leg tarsi 5-segmented; fore coxal cavites open behind ... Erotylidae

122(119).

Beetles dorsally strongly convex; front tarsi 4-segmented; mid-leg tarsi 4-segmented; hind tarsi 4-segmented ... Coccinellidae Beetles cylindric; front tarsi 5-segmented; mid-leg tarsi 5-segmented; hind tarsi 5-segmented ... Byturidae

123(118).

Compound eyes finely facetted; beetles not necked; mid-leg tarsi 5-segmented; the claws of the mid-leg tarsi one-toothed or bifid; hind tarsi 5-segmented ... Byturidae Compound eyes coarsely facetted; beetles conspicuously necked; mid-leg tarsi 3-segmented; the claws of the mid-leg tarsi simple; hind tarsi 3-segmented ... Pselaphidae

124(118).

Adults 1.5 to 5 mm long ... 125 Adults 5.1 to 20 mm long ... Cleridae

125(124).

Prothorax having the front corners produced, or with serrated sides; the claws of the mid-leg tarsi simple ... Silvanidae Prothorax with neither produced front corners nor serrated sides; the claws of the mid-leg tarsi one-toothed or bifid ... Byturidae

126(115).

Antennae with the scape much-elongated ... 127 Antennae without a much-elongated scape... 130

127(126).

Antennae strongly asymmetric; antennal clubs lamellate ... Lucanidae Antennae not strongly asymmetric; antennal clubs not lamellate... 128

128(127).

Beetles conspicuously necked; antennae not elbowed; exposed abdominal sternites 6 to 7 ... Staphylinidae Beetles not necked; antennae conspicuously elbowed; exposed abdominal sternites 5... 129

129(128).

Beetles dorsally flattened; beetles oval ... Histeridae Beetles cylindric; beetles elongate ... Platypodidae

130(126).

Apparent tarsal segmentation 0, 5, 5 ... Scarabaeidae Apparent tarsal segmentation 5, 5, 5... 131 Apparent tarsal segmentation 5, 5, 4... 145 Apparent tarsal segmentation 4, 4, 4... 148 Apparent tarsal segmentation 3, 3, 3... 153 Apparent tarsal segmentation 5, 4, 4 ... Colydiidae Apparent tarsal segmentation 5, 3, 3 ... Leiodidae Apparent tarsal segmentation 4, 3, 3 ... Leiodidae Apparent tarsal segmentation 0-2, 3, 3 ... Pselaphidae

131(130).

Antennal clubs lamellate ... 132 Antennal clubs not lamellate... 133

132(131).

Antennae strongly asymmetric ... Scarabaeidae Antennae not strongly asymmetric ... Trogidae

133(131).

Beetles not waisted ... 134 Beetles somewhat waisted... 136 Beetles conspicuously waisted... 139

134(133).

Antennal clubs up to 3 segmented ... Biphyllidae Antennal clubs 4 to 9 segmented... 135

135(134).

Antennal segment 8 smaller than segments 7 and 9 ... Leiodidae Antennal segment 8 not smaller than 7 and 9 ... Scaphidiidae

136(133).

The maxillary palps conspicuously elongated, often longer than the antennae ... Hydrophilidae The maxillary palps not especially elongated... 137

137(136).

Antennal clubs up to 3 segmented ... Biphyllidae Antennal clubs 4 to 9 segmented... 138

138(137).

Antennal segment 8 smaller than segments 7 and 9 ... Leiodidae Antennal segment 8 not smaller than 7 and 9 ... Scaphidiidae

139(133).

Antennal clubs preceded by a cupule; metaventrite with a transverse groove ... Sphaeritidae Antennal clubs without a cupule; metaventrite without a transverse groove... 140

140(139).

Base of prothorax not or scarcely narrower than the combined elytral bases ... 141 Base of prothorax distinctly narrower than the combined elytral bases... 142

141(140).

Exposed abdominal sternites 5 ... Phloiophilidae Exposed abdominal sternites 6 to 7 ... Scydmaenidae

142(140).

Antennae 9 to 10 segmented ... Rhizophagidae Antennae 11 segmented... 143

143(142).

Beetles terrapin-like in shape, with flattened and clear margins to thorax and elytra; adults not predacious ... Peltidae Beetles not terrapin-like in shape, and without flattened and clear margins to both thorax and elytra; adults predacious... 144

144(143).

Beetles conspicuously necked; exposed abdominal sternites 6 to 7 ... Scydmaenidae Beetles not necked; exposed abdominal sternites 5 ... Cucujidae

145(130).

Antennal segment 8 smaller than segments 7 and 9 ... Leiodidae Antennal segment 8 not smaller than 7 and 9... 146

146(145).

Antennae 9 to 10 segmented ... 147 Antennae 11 segmented ... Cucujidae

147(146).

The tarsi with a tiny basal segment that is hard to detect ... Trogossitidae The tarsi without ‘hidden’ segments ... Rhizophagidae

148(130).

Beetles not waisted ... Mycetophagidae Beetles somewhat waisted... 149 Beetles conspicuously waisted... 150

149(148).

Compound eyes finely facetted; mandibular prosthecae absent; prothorax about as long as wide; elytra without striae; elytral epipleura reaching to the tips of the elytra ... Cisidae Compound eyes coarsely facetted; mandibular prosthecae well developed; prothorax shorter than wide; elytra striate; elytral epipleura falling short of the elytral tips ... Mycetophagidae

150(148).

Beetles terrapin-like in shape, with flattened and clear margins to thorax and elytra ... Peltidae Beetles not terrapin-like in shape, and without flattened and clear margins to both thorax and elytra... 151

151(150).

Mid-leg tarsi 3-segmented ... Colydiidae Mid-leg tarsi 4-segmented ... Colydiidae Mid-leg tarsi 5-segmented... 152

152(151).

Elytra non-glabrous; upper surfaces of body non-glabrous; wings fringed with long hairs on the hind margin; adults associated with dung ... Hypocopridae Elytra glabrous; upper surfaces of body glabrous or subglabrous; wings not fringed; adults under bark ... Cucujidae

153(130).

Beetles conspicuously necked ... 154 Beetles not necked... 155

154(153).

Prothorax shorter than wide; elytra covering most to all of the abdomen; adults not predacious; larvae not predacious ... Lathridiidae Prothorax about as long as wide; elytra short, exposing several terminal abdominal tergites; adults predacious; larvae predacious ... Pselaphidae

155(153).

Beetles somewhat waisted ... Cisidae Beetles conspicuously waisted... 156

156(155).

Elytra glossy; fore coxal cavites closed behind ... Merophysiidae Elytra dull; fore coxal cavites open behind ... Colydiidae

157(114).

The tarsi exhibiting bilobed segments ... 158 The tarsi without bilobed segments... 160

158(157).

Prothorax shorter than wide; prothorax at its widest not markedly narrower than the adjoining part of the abdomen; adults not predacious; larvae not predacious ... 159 Prothorax longer than wide; prothorax at its widest markedly narrower than the adjoining part of the abdomen; adults predacious; larvae predacious ... Cleridae

159(158).

Elytral epipleura reaching to the tips of the elytra ... Erotylidae Elytral epipleura falling short of the elytral tips ... Cryptophagidae

160(157).

Beetles exhibiting bright ‘warning colours’ ... Tetratomidae Beetles without ‘warning colouration’... 161

161(160).

Antennae with the scape much-elongated ... 162 Antennae without a much-elongated scape... 163

162(161).

Beetles conspicuously necked; antennae not elbowed; prothorax longer than wide; exposed abdominal sternites 6 to 7 ... Staphylinidae Beetles not necked; antennae conspicuously elbowed; prothorax shorter than wide; exposed abdominal sternites 5 ... Histeridae

163(161).

The end of the abdomen extended as a long, narrow point beyond the ends of the truncate elytra; the claws of the mid-leg tarsi serrate, denticulate or pectinate ... Mordellidae The end of the abdomen not extended as a long, narrow point beyond the ends of the elytra; the claws of the mid-leg tarsi simple... 164

164(163).

Scutellary striole present ... 165 Scutellary striole absent... 166

165(164).

Antennal insertions visible from above; apparent tarsal segmentation 4, 4, 4; exposed abdominal sternites all articulated and movable ... Sphindidae Antennal insertions hidden from above; apparent tarsal segmentation 5, 5, 4; exposed abdominal sternites comprising both fused and movable components ... Tenebrionidae

166(164).

Antennal segment 8 smaller than segments 7 and 9 ... Leiodidae Antennal segment 8 not smaller than 7 and 9... 167

167(166).

Exposed abdominal sternites all articulated and movable ... 168 Exposed abdominal sternites comprising both fused and movable components ... Tenebrionidae

168(167).

Antennae 9 to 10 segmented; elytral epipleura falling short of the elytral tips ... Rhizophagidae Antennae 11 segmented; elytral epipleura reaching to the tips of the elytra ... Cucujidae

169(1).

Hind coxae posteriorly shaped to receive the retracted femur ... 170 Hind coxae not shaped posteriorly to receive the femur... 175

170(169).

Beetles clicking and ‘jumping’ to right themselves when inverted ... Elateridae Beetles not clicking and ‘jumping’... 171

171(170).

Abdominal segment 8 with apparently functional spiracles ... 172 Abdominal segment 8 apparently without functional spiracles... 174

172(171).

The tarsi exhibiting bilobed segments; metaventrite with a transverse groove ... Buprestidae The tarsi without bilobed segments; metaventrite without a transverse groove... 173

173(172).

The head covered by the thorax; exposed abdominal sternites comprising both fused and movable components ... Anobiidae The head not covered by the thorax; exposed abdominal sternites all fused and immovable ... Eucnemidae

174(171).

The head covered by the thorax; metaventrite without a transverse groove; beetles dorsally somewhat convex; hind coxae without the steep transverse declivity characteristic of Dryopoidea ... Anobiidae The head not covered by the thorax; metaventrite with a transverse groove; beetles dorsally strongly convex; hind coxae with a steep transverse declivity against which the femur retracts ... Psephenidae

175(169).

Apparent tarsal segmentation 5, 5, 5 ... 176 Apparent tarsal segmentation 5, 5, 4 ... Pyrochroidae Apparent tarsal segmentation 4, 4, 4... 178

176(175).

Abdominal segment 8 with apparently functional spiracles; beetles exhibiting bright ‘warning colours’ ... Lycidae Abdominal segment 8 apparently without functional spiracles; beetles without ‘warning colouration’... 177

177(176).

Elytra meeting along the length of the mid-line; adults predacious; larvae predacious ... Melyridae Elytra not meeting along the full length of the mid-line; adults not predacious; larvae not predacious ... Lymexylidae

178(175).

Compound eyes accommodating the antennae in an anterior notch; elytra truncate; elytra non-glabrous; larvae eating dried plant material or stored plant products ... Bruchidae Compound eyes not accommodating the antennae in a notch; elytra not truncate; elytra glabrous; larvae phytophagous ... Chrysomelidae

179(1).

Hind coxae posteriorly shaped to receive the retracted femur ... 180 Hind coxae not shaped posteriorly to receive the femur... 182

180(179).

Beetles clicking and ‘jumping’ to right themselves when inverted ... Elateridae Beetles not clicking and ‘jumping’... 181

181(180).

The head covered by the thorax; exposed abdominal sternites comprising both fused and movable components ... Anobiidae The head not covered by the thorax; exposed abdominal sternites all fused and immovable ... Eucnemidae

182(179).

Hind tarsi with as many segments as the mid-tarsi; abdominal segment 8 with apparently functional spiracles; apparent tarsal segmentation 5, 5, 5 ... 183 Hind tarsi with one segment fewer than the mid-tarsi; abdominal segment 8 apparently without functional spiracles; apparent tarsal segmentation 5, 5, 4... 185

183(182).

The scutellum elevated abruptly and fairly sharply above the mesoscutum in lateral view; exposed abdominal sternites comprising both fused and movable components; hind coxae with a steep transverse declivity against which the femur retracts; adults not predacious ... Dryopidae The scutellum not elevated; exposed abdominal sternites all articulated and movable; hind coxae without the steep transverse declivity characteristic of Dryopoidea; adults predacious... 184

184(183).

Beetles somewhat waisted; beetles exhibiting bright ‘warning colours’; the tarsi without bilobed segments ... Lycidae Beetles conspicuously waisted; beetles without ‘warning colouration’; the tarsi exhibiting bilobed segments... Drilidae (males)

185(182).

Beetles dorsally flattened; the tarsi exhibiting bilobed segments; elytra not individually tapered; elytra meeting along the length of the mid-line; beetles not asymmetrically humped and tapered ... Pyrochroidae Beetles dorsally strongly convex; the tarsi without bilobed segments; elytra individually distinctly tapered to their apices; elytra not meeting along the full length of the mid-line; beetles asymmetrically humped, and tapered to the rear ... Rhipiphoridae

To view the illustrations with detailed captions, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. British insects: the families of Coleoptera. Version: 1st April 2012. http://delta-intkey.com’.

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