Beetles Identification Guide

30
Key H TENEBRIONIDAE
1(0) Integument of elytra bicolorous, reddish brown with transverse yellow
spots. [Length of body 2.2—3.1 mm; habitus Fig. 232] ........................
...............................................................Alphitophagus bifasciatus (p.175)
Integument of elytra unicolorous ..........................................................2
2(1) Length of body more than 10 mm ..................................... (Tenebrio) 3
Length of body less than 8 mm ..............................................................4
3(2) Clypeus, frons, and disc of pronotum with punctures confluent or
separated by distance usually shorter than diameter of one puncture (Fig.
159). Dorsum dull. [Length of body 13—17 mm] ...............................
......................................................................... Tenebrio obscurus (p.186)
Clypeus, frons, and disc of pronotum with punctures not confluent,
separated by distance usually greater than diameter of one puncture (Fig.
160). Dorsum more or less shiny. [Length of body 12—17 mm; habitus
Fig. 238] ............................................................ Tenebrio molitor (p.184)
4(2) Eye entire, not incised by side margin of head (Fig. 146) ..... (Palorus) 5
Eye incised or divided by side margin of head (Figs. 147—149) ...........6
5(4) Margin of gena somewhat angulate laterally, lower than margin of clypeus
anteriorly (Fig. 150). Gena on same level as frons near eye. [Length of
body 2.3—3.0 mm; habitus Fig. 237] ...........Palorus ratzeburgii (p.180)
Margin of gena rounded laterally, at same level or slightly higher than
margin of clypeus anteriorly (Fig. 151). Gena reflexed near eye. [Length
of body 2.5—3.0 mm] ................................ Palorus subdepressus (p.184)
6(4) Eye divided by side margin of head (Fig. 147). [Length of body 4.0—5.5
mm; habitus Fig. 233] .............................. Blapstinus substriatus (p.177)
Eye incised by side margin of head (Figs. 148 and 149) ........................7
7(6) Pronotum with lateral bead continuous over anterior margin (generally
obsolete at middle) (Figs. 162—164). Elytra with intervals flat ..........8
Pronotum with lateral bead not continuous over anterior margin
(Fig. 161). Elytra with intervals finely, though usually distinctly, carinate
.......................................................................................... (Tribolium) 11
8(7) Pronotum with basal margin markedly sinuate (Figs. 162 and 163). Disc
of pronotum without or with faint microsculpture between punctures.
Body rather broad (see Fig. 231) ..................................... (Alphitobius) 9
Pronotum with basal margin straight or slightly sinuate (Fig. 164). Disc
of pronotum with strong microsculpture between punctures. Body rather
narrow (see Figs. 234—236] ................................................................10