166 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
KEY TO THE GENERA OF LAMELLICORN BEETLES IMPORTANT TO FORESTRY IN 
EASTERN NORTH AMERICA—Continued 
Size over 40 mm. long; color greenish gray with black spots or uni- 
form dark brownish, or with both color patterns. (Dynastinae) 
Dynastes FF 
25. Hind tibiae with several blunt, rounded teeth at tip; vertex of head 
with horn in male, tubercle in female. (Dynastinae)_Xyloryctes EE 
Hind tibiae cut off squarely at tip and fringed with spines; head 
with a low, transverse ridge, indistinct in Aphonus____________ 26 
29. Mandibles not toothed on outer side; clypeus with a 3-toothed 
process just before the tip. (Dynastinae)___________ Aphonus iP 
Mandibles toothed on the outer side; clypeus usually bidentate 
VG pe eS a oY a ae Ae eau a oe eee Pa 
27. Front margin of pronotum always with a tubercle, posterior. to 
which is a shallow depression; union of elypeus and front marked 
by a low ridge which, in some species, is slightly more pronounced 
atieachwerdee GDyyanais tise) ee eee pee eee eee Ligyrus Q 
Pronotum never with a tubercle followed by a depression; union of 
clypeus marked by 2 low ridges, one at a right angle to each 
lateral margin, area between ridges not, or only very slightly, 
elevated. (Dynastinae) asi mas Eee, ee ee Ligyrodes R 
28. Wing covers sinuate on the sides posterior to the basal humeral 
angles; sides (epimera) of mesothorax visible from above______-_ 29 
Wing covers not sinuate on the sides posterior to the basal front 
angles; sides (epimera) of mesothorax conspicuous from above__ 31 
29. Pronotum lobed or pointed at base, the lobe covering the scutellum_ 30 
Pronotum not lobed at the base so as to cover the scutellum, which 
is roughly triangular; mentum normal in shape: clypeus narrow, 
reflexed; color never predominantly black. (Cetoniinae) 
Euphoria O 
30. Head of both sexes with a distinct frontal and clypeal horn, the 
latter being proportionately wide and thin; wing covers greenish 
with a tan or gold lateral border. (Cetoniinae)_________Cotinis at 
Head unarmed in either sex; wing covers black and white mottled; 
Confnedstossoutawestan 1¢Cetominmcie) mera ae enna Gymnotis S 
31. Body hairy dorsally; color variegated; size less than 138 mm. long; 
wing covers little longer than wide; pronotum rounded at base. 
(GErichiimge Pie 2 eee ee ee Trichiotinus U 
Body not hairy dorsally; color very dark brown to piceous; wing 
covers heavy and leatherlike; sculpture smooth or rough; size 18 
dA GR Op ivaKor ge, lkoayer, — (Ahokelowiinpys) = eae ee Osmoderma AA 
KEY TO THE GENERA OF LAMELLICORN LARVAE IMPORTANT TO FORESTRY IN 
EASTERN NORTH AMERICA 
All larvae of the lamellicorn group have 5-jointed legs, with the 
tarsal joint fused with the single claw into a terminal spine (so far as 
treated in this key). There is a median epicranial suture present: 
the tenth abdominal segment is well developed, being usually about 
as large as or larger than the ninth, to which it 1s sometimes fused 
dor sally, When shorter than the ninth the tenth segment is provided 
with a pair of large anal pads. The spiracles are sievelike in struc- 
ture (except in some species of Z’rowv, which are not included here) 
and all are lateral. ‘These insects constitute the series Scarabaeoidea. 
Ale Form scarcely curved; 3rd pair of legs poorly developed; antennae 
3-segmented; anal slit transverse. In decayed wood, especially 
hardwood. (Family Passalidae) == 222222525 (Passalus) Popilius 
Form curved, tip of abdomen usually touching legs; 3rd pair of 
less developed: normally 22 2 22 25 See ee ee ee 2 
2. Anal segment strongly bilobed on caudal aspect; stridulating organs 
on 2nd and 3rd pairs of legs; anal pads very large and conspicuous; 
labrum trilobed. In decayed wood, especially hardwood. 
(Family: Lucanidae)). 2529 eee a ee eee eee 3 
