INSECT ENEMIES OF EASTERN FORESTS 169 
KEY TO THE GENERA OF LAMELLICORN LARVAE IMPORTANT TO FORESTRY IN 
EASTERN NORTH AMERICA—Continued 
27. Spines of raster strongly hooked; abdominal spiracles increasing 
somewhat in size toward caudal end, with the eighth the largest; 
left mandible without lateral teeth between bidentate tip and 
molar structure. In soil under turf of lawns, golf courses, ete. 
QD yrastimae)ere eee = wey ee oh eee ue eS Ochrosidia 
Spines of raster not hooked, but are straight or slightly curved____ 28 
28. Epipharyngeal plate produced into 2 or 3 processes or teeth______ 29 
Epipharyngeal plate produced into a single large tooth___________ 30 
29. End of epipharynx in front of plate beset with forked, brushlike 
setae; left mandible with 1| lateral tooth in front of molar struc- 
ture; abdominal spiracles approximately the same in size. In 
sandy soil in plowed and fallow fields, gardens, etc. (Dynastinae) 
Ligyrus 
End of epipharynx in front of plate not beset with forked, pees 
setae; spiracles variable in size; head strongly punctured, and, 
with mandibles, nearly black; prothorax with a large, brown, 
heavily chitinized, deeply bipunctate area on sides; extremely 
large grubs at maturity. In decayed wood, especially hard- 
WOO Ctamn CD iysINASGIIMNAC)) Meee ue ee eee a ee oa ee Dynastes 
30. Last, or eighth, abdominal spiracle distinctly smaller than the pre- 
ceding ones; left mandible with 1 lateral tooth; head very dark 
to blackish. In humus layer of heavy hardwoods; sometimes in 
much decayed wood or litter. (Dynastinae)________ Xyloryctes 
/ 
Last 3, or sixth, seventh, and eighth, abdominal spiracles distinetiy 
smaller than the preceding spiracles: head medium brown, cov- 
ered with robust setae placed in deep pits, front of head with a 
distinct purplish-brown spot; head capsule reduced in size, being 
smaller than thoracic segments; left mandible without a lateral 
tooth. In sandy soil of open forests; probably in soil of gardens, 
FOlRCOUTSeS etc eC Dy nastinage)! 26 2 Ye ey Aphonus 
Famities PASSALIDAE and LUCANIDAE 
The Stag Beetles 
The two families Passalidae and Lucanidae contain small to very 
large beetles closely resembling the Scarabaeidae, and distinguished 
from them chiefly by having the plates of the antennal club rigid and 
incapable of being opened or closed. Some of the Lucanidae, however, 
differ conspicuously in that they have very large, hornlike mandibles 
which project in front of the head. 
The larvae of these two families also resemble those of the Scara- 
baeidae, but, unlike them, have anal lobes that are developed into two 
large lateral pads, and have stridulatory or “sound” organs on the 
third pair of legs rather than on the mandibles. 
The stag beetles are all borers in dead or decaying wood and conse- 
quently of little importance except to the forester or recreationist who 
may be piscatorially inclined. Then, a knowledge of the breeding 
habits of these forms will serve the angler with a supply of excellent 
grubs for fish bait. nee 
The Passalidae are represented by only one species in the United 
States. This is Popilius disjunctus (Il.) which is of interest because 
of its social habits, the adults tending the larvae in the ample brood 
galleries, where all move about freely in a very deliberate and pon- 
derous manner. The common name of “betsy-bug,” or “bess-bug,” 
is given this species, probably because of the “bess-bess” note made by 
the adults when molested. This beetle was discussed by Pearse, 
Patterson, Rankin, and Wharton (347). 
