RN  ___— eee 
by the Dutch elm disease. Buchanan (115) demonstrated its 
ability to transmit the Dutch elm disease fungus to healthy trees. 
FAMILY PLATYPODIDAE 
All members of this family are ambrosia beetles and they occur 
principally in the tropics and subtropics. Only one genus has been 
recorded from the United States. The adults differ from those of | 
other ambrosia beetles in having longer and more slender bodies | 
and wide heads flattened in front. The first segment of the tarsus | 
is as long as all the other tarsal segments combined, and there are | 
spine-like projections at the seam of the elytra of the males. | 
Members of the family are usually more destructive than other . 
ambrosia beetles. Their tunnels are more extensive, and they ex- | 
tend deeper into the sapwood and heartwood. Dying, weakened, 
or recently felled trees are usually preferred; however, vigorous, 
healthy trees are also attacked if dead areas of bark are present. 
Eges are laid in small loose clusters in the tunnels. Larvae and 
adults are also found in these tunnels. 
Platypus flavicornis (Fab.) breeds commonly in various species | 
of pines and occasionally in several hardwoods. Dead and dying | 
trees, stumps, and logs cut or left in the woods during the summer 
are preferred. Adults are reddish-brown and about 5 mm. long. 
The front of the head is flat and clothed with moderately long 
hairs; the pronotum is longer than broad and densely but shal- 
lowly punctured; and the elytra are elongate and striate, with the 
third, fifth, seventh, and ninth interspaces produced into tooth- 
like processes on the declivity of the male. The adult bores a 
horizontal gallery in the sapwood (fig. 102). Here, it may branch 
extensively and extend deep into the heartwood. The lower por- 
tions of infested trees are sometimes literally riddled. In the 
south, this species is so abundant that very few dying pines, 
COURTESY OF DUKE UNIV. SCH. OF FOREST. 
™  FicurRE 102.—Tunnel of the am- 
brosia beetle, Platupus flavi- 
cornis, in a chip from a recently 
felled shortleaf pine. 
272 | 
