156 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
KEY TO THE FAMILIES OF MORE IMPORTANT BEETLE LARVAE—Continued 
41. Legs well developed, 5-jointed: ninth abdominal segment armed; 
body elontate. 2.2 =.) ee ea ee eee Lymexylonidae 
Legs weak; ninth abdominal segment unarmed: body curved: larvae 
in bark or wood beneath the sporophores of woody fungi 
Anthribidae 
42. Ninth abdominal segment ending in a single truncate spine or in 
paired: spines: 2 2 oe ae ee eee Mordellidae 
Ninth abdominal segment unarmed, except some first-instar larvae_ 43 
43. Tenth abdominal segment provided with a pair of cushioned lobes 
(not anal lobes) separated by a median suture: fleshy, curved 
hairy forms, usually with slender 4- or 5-jointed legs: wood-boring 
fornisi. =. 2! ee eee ee Bostrichidae, Ptinidae 
44, Elongate, ease larvae in the roots of hickory trees 
Disteniinae (Cerambycidae) 
Porm ‘otherwise:.2. 6-42 es. 5 eee ee + 
45. Legs vestigial, 2-jointed; cylindrical, fleshy, wood-boring form, 
with chitinous asperities on prothorax and abdominal terga 
Brentidae 
Legs 4- or 5-jointed except occasionally wanting in some leaf-mining 
forms: maxillary mala often divided; hypopharyngeal bracon 
absent. <2. 5.22200 ba ee2 2 SP eae ee ee ee eee ee 46 
Legs wanting; mala always simple; bracon present______________ 47 
46. Mentum bearing a shieldlike plate: labial palpi absent or rudimen- 
tary; feeding in the seeds of plants____- Coe Brichidae 
Mentum without such plate; labial palpi rarely wanting 
C hrysomelidae 
47. Adults usually associated with the larvae and boring characteristic 
galleries in the wood or under the bark of shrubs, trees, or lumber 
Platypodidae, Scolytidae 
mr 
Larvae. and adults notiso associnted] =) 48 
48. Abdominal segments with two transverse folds: larvae often found 
in a compacted roll cut from a leaf___Curculionidae, Attelabinae 
Abdominal segments with 3 or 4 transverse folds________________ 49 
49, Larvae boring in the moist sapwood of dead trees or occasionally in 
beams of buildings, powder-posting the material 
Curculionidae, Cossoninae 
Habits of larvae variable: not working like powder-post beetles 
Curculionidae 
Famity CARABIDAE 
The Ground Beetles 
The ground beetles make up a large family of beetles of interest to 
the forester chiefly because of their beneficial or predatory habits. 
Several larger species of Ca/osoma are also expert climbers and are 
voracious feeders on caterpillars, destroying great numbers of these 
destructive defoliators. Others stay on the oround, hunting living in- 
sects in the leaf litter and under logs or stones. while some forms live 
under the bark of dead trees or logs. Nearly every habitat of the 
forest is occupied by some form or forms of this family, and each form 
is specially adapted to living or procuring food under special circum- 
stances. One interesting adaptation of this kind 1s represented by the 
old genus Cychrus, now Scaphinotus, the members of which frequent 
cool, damp ravines, where the beetles feed on snails. These large 
beetles are provided with an elongate head and mandibles well fitted 
for removing the snail’s body from its shell. 
The carabid larvae are elongate, fusiform, usually active species 
with darkly chitinized integument in the free-living forms. but white 
and thin textured in eround or bark-inhabiting forms. The man- 
