342 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
ambrosia beetles by their larger size; their slender, cylindrical bodies: 
their large prominent heads, “flattened in front; the very long, slender 
tarsus, with the basal joint longer than the others combined ; the 
slender thorax, constricted about midway at the sides; and in the 
males by the spinelike projections of the elytra behind. 
The Platypus beetles are more destructive than ordinary ambrosia 
beetles because their burrows are more extensive and often penetrate 
deep into the heartwood of the trees attacked, thus destroying more of 
the valuable timber. The eggs are laid in small clusters, loose in the 
burrows, each female depositing from 100 to 200. The larvae at first 
live freely in the tunnels along with the adults and, like the latter, 
feed on a minute fungus which forms a coating over the walls of the 
burrow, producing the black stain characteristic of the burrows. After 
about 5 or 6 weeks, when the larvae are nearly full grown, each ex- 
cavates a small ail at one side of the main burrow. These cells are 
usually placed in groups of 8 or 10, or more, and always extend with 
the grain of the wood. In these cells the larvae transform to pupae 
and later to adults. The beetles seldom or never attack vigorous, 
healthy trees, for, although the tree attacked may be in full foliage, 
the insects enter through < some dead or dying area of the bark. 
Apparently a fermenting condition of the sap is necessary for the 
proper development of the ambrosial fungi on which the young depend 
entirely and the adults largely for their food. Thus the Platypus 
beetles are perhaps never the primary cause of the death of trees, but 
their activities may result in hastening the death of injured or sickly 
trees. More important still, their burrows often ruin the timber value 
of girdled trees or large trees recently felled in the course of lumbering 
operations. There are only three species of Platypus commonly found 
in the Eastern States and of these only two are often of real im- 
portance. For control measures against these beetles see pages 38-40. 
Additional information may be obtained by referring to Black- 
man (38). 
Platypus flavicornis is dark reddish brown, more than 5.5 mm. 
long; the pronotum with an unmargined. shallow fovea at each side 
of the anterior end of the longitudinal groove in the female only: 
the posterior end of the female elytra is pr rolonged at each outer third 
to form a blunt process, which in the male is much longer and shar per. 
P. flavicornis is common throughout the Southeastern States and is 
found as far north as New Jersey. It is most common in various 
species of pine, but also breeds in other conifers and has been reported 
from several deciduous trees. However, throughout the South the 
chief damage is done to pine trees, and as the beetles are energetic 
burrowers and often attack in considerable numbers, the wood is soon 
rendered worthless as saw timber and its value as cordwood is much 
decreased. Trees or logs attacked should be utilized at once. 
Platypus compositus is rather light reddish brown and less than 
5 mm. in length. The pronotum is finely, shallowly, and sparsely 
punctured, with a distinct longitudinal groove on the posterior third, 
and with a small margined pit at each side, near the anterior end of 
the groove in both sexes. The males have the wing covers each pro- 
longed into a heavy process, tridentate at the end, while in the females 
the elytra are somewhat truncate and unarmed. P. compositus is 
found throughout the Southern States and has been taken as far north 
