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No. of species: World, 290,000; N. America, 28,600. Identification of beetles: The pictured key (pp. 148-149) to the more common families of beetles should be of help to those not well acquainted with these insects. A comparison of the specimen to be identified with the 1st pair of alternatives will lead to further pairs, and eventually to a group of families in which the specimen belongs. Families marked with a dagger are the most common, and descriptions and illustrations of these should be checked first. Families with an asterisk (somewhat less common) should be checked next, and families without symbols are least common and can be checked last. If, from the descriptions and illustrations vu \y

Types of antennae (A-I) and body shapes (J-N) in beetles. A, threadlike; B, beadlike; C, D, and E, clubbed (E, capitate); F, serrate; G, elbowed; H, lamellate; I, pectinate; J, elongate-slender, nearly parallel-sided; K, elongate-slender; L, elongate-oval; M, elongate-robust; N, broadly oval.

Types of antennae (A-I) and body shapes (J-N) in beetles. A, threadlike; B, beadlike; C, D, and E, clubbed (E, capitate); F, serrate; G, elbowed; H, lamellate; I, pectinate; J, elongate-slender, nearly parallel-sided; K, elongate-slender; L, elongate-oval; M, elongate-robust; N, broadly oval.

Key to the Principal Families of Coleoptera f- -

1st abdominal segment divided by hind coxae (concealed in Haliplidae)

fCarabidae, p. 152 fCicindelidae, p. 151 fDytiscidae, p. 154 f Haliplidae, p. 152 fGyrinidae, p. 154 Omophronidae, p. 152 Rhysodidae, p. 151

Head lacking beak or snout Antennae threadlike, serrate, or otherwise, and not clubbed

I or more complete abdominal segments visible beyond FW

f Staphylinidae p. 160 ♦Bruchidae, p. 200 Scaphidiidae, p. 159 Pselaphidae, p. 160 Rhipiphoridae, p. 184 Malachiidae, p. 164 Dasytidae, p. 164

f—the most common families *—less common families no symbol—least common

1st abdominal segment not divided by hind coxae

Head with beak or snout """" fCurculionidae, P- 202

♦Bruchidae, p. 200 Anthribidae, p. 202 Brentidae, p. 201 0{ Salpingidae, p. 182

^ Antennae with a distinct club of various k«nds (to next page)-

^ Antennae with a distinct club of various k«nds (to next page)-

^ No abdominal segments exposed beyond FW

Antennae threadlike or beadlike Head nearly or quite concealed by pronotum from dorsal view fChrysomelidae, p. 198 fLampyridae, p. 162 ♦Anthicidae, p. 181 ♦Mordellidae, p. 185 Lycidae, p. 163 Elmidae, p. 172 Dascillidae, p. 170 Helodidae, p. 170 Leptodiridae, p. 158 Eucnemidae, p. 168 Throscidae, p. 168 Ptinidae, p. 188

Mandibles directed downward or posteriorly

Pronotum keeled laterally

Pronotum keeled laterally

^ No abdominal segments exposed beyond FW

■Antennae serrate, pectinate, or plumose fElateridae, p. 166 fBuprestidae, p. 169 fLampyridae, p. 162 ♦Mordellidae, p. 185 Lycidae, p. 163 Ptilodactylidae, p. I 70 Rhipiphoridae, p. 184 Pyrochroidae, p. 183 Eucnemidae, p. 168 Throscidae, p. 168

-Head not concealed from dorsal view

Mandibles directed anteriorly fTenebrionidae, p. I 86 fCantharidae, p. 162 ♦Alleculidae, p. 187 ♦Cucujidae, p. 176 Dascillidae, p. 170 Lagriidae, p. 186 Salpingidae, p. 182

fChrysomelidae, p fCerambycidae, p. 196 fTenebrionidae, p. 186 fCantharidae, p. 162 ♦Melandryidae, p. 18 Lycidae, p. 163 Helodidae, p. 170 Dasytidae, p. 164 Psephenidae, p. 172

Pronotum rounded laterally fChrysomelidae, p. 198 fCerambycidae, p. 196 f Meloidae, p. 184 ♦Anthicidae, p. 181 Cleridae, p. 165 Euglenidae, p. 181 Pedilidae, p. 183

Key to the Principal Families of Coleoptera (contd.)

Last 3 or 4 (or more) antennal segments markedly prolonged laterally fScarabaeidae, p. 192 *Lucanidae, p. 190 ♦Passalidae, p. 191 Sandalidae, p. 166 Ostomidae, p. 164 Cleridae, p. 165 Heteroceridae, p. 172

No abdominal segments exposed y beyond FW

Very compact, nearly or quite spherical from dorsal view fCoccinellidae, p. 180 fChrysomelidae, p. 198 t Dermestidae, p. 164 *Erotylidae, p. 176 ♦Hydrophilidae, p. 156 ♦Nitidulidae, p. 177 ♦Phalacridae, p. 178 Leiodidae, p. 158 Byrrhidae, p. 173 Anobiidae, p. 188

Head not concealed from dorsal view

Antennal club asymmetrical

'"Hydrophilidae p. 156

KSilphidae, p. 158 Ostomidae, p. 164 Psoidae, p. 190 Dryopidae, p. 172 Elmidae, p. I 72 Heteroceridae, p. Cleridae, p. 165

Pronotum not narrower than FW at base

Mandibles directed forward fTenebrionidae, p. 186 *Hydrophilidae, p. 156 *Cucujidae, p. I 76 *Languriidae, p. 175 ♦Silphidae, p. 158 *Erotylidae, p. 176 Derodontidae, p. 174 Silvanidae, p. 178 Colydiidae, p. 180 Mycetophagidae, p. 181

Terminal antennal segments not prolonged laterally

I or more abdominal segments visible beyond FW

fStaphylinidae, p. 160 *Nitidulidae, p. 177 *Histeridae, p. 156 ♦Silphidae, p. 158 ♦Bruchidae, p. 200 Pselaphidae, p. 160 Scaphidiidae, p. 159 Monotomidae, p. 174

^Elongate or linear, not spherical from dorsal view

- Head nearly or quite concealed by pronotum from dorsal view fChrysomelidae, p. 198 fDermestidae, p. 164 *Mordellidae, p. 185 ♦Anthicidae, p. 181 Anobiidae, p. 188 Bostrichidae, p. 189 Cisidae, p. 164 Scolytidae, p. 204 Mycetophagidae, p. 181 Leptodiridae, p. 158 Byturidae, p. I 78 Throscidae, p. 168

Antennal club symmetrical

Pronotum narrower than FW at base

*Cucujidae, p. 176 Derodontidae, p. 174 Cleridae, p. 165 Lathridiidae, p. 178 Lyctidae, p. 190

Mandibles directed downward fChrysomelidae, p. 198 *Hydrophilidae, p. 156 ♦Anthicidae, p. 181 *Erotylidae, p. 176 Throscidae, p. 168 Mycetophagidae, p. 181 Cryptophagidae, p. 175 Mycetaeidae, p. 179 Endomychidae, p. 180 Leptodiridae, p. 158

Antennal club symmetrical

Mandibles directed downward given, the specimen does not appear to belong to any of the families in the group, descriptions and illustrations of related groups should be examined. Should there be doubt at any point in the key as to which way to proceed, try both alternatives. After practice you will recognize the most common groups, and identification of subsequent specimens will be easier. The key is so arranged that some variable families key out in more than one place. In the following text, tarsal segmentation is indicated by a 3-number formula (like 5-5-5), representing the number of segments in the front, middle, and hind tarsi.

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