10 
Indian Forest Records. 
[Vol. VI 
While these latter are more or less mechanically produced by the ex¬ 
tension of the entrance burrow through the resin-flow from the host- 
tree, in the case of Diapus furtivus the wax-tube appears to be con¬ 
structed by the beetle on a definite plan for a definite purpose. Its 
presence at the entrance to the galleries makes it more difficult for 
enemies to gain access, and it also renders the ejection of frass-particles 
more easy. We have seen the male of Diapus furtivus blocking up 
the wax-tube with its body, and effectually preventing the entrance 
of a crowd of small mites swarming outside on the bark. The projec¬ 
tion of the tube, above the general level of the bark, also presents certain 
difficulties, in negotiation to the long-bodied predaceous beetles, which 
occur commonly in the galleries of other species of Platypodidae which 
do not possess this protective device. The only other species of Indian 
Platypodidae, which constructs a wax-tube, as far as the writer is aware, 
is Diapus impressus, Janson, which breeds in Quercus incana , in the 
Himalayas. The second species of Diapus , D. quinquespinatus, Chapuis, 
which finds a host in the Sal, curiously enough does not construct a 
wax-tube. 
Construction of the Wax-Tube. 
The wax is secreted by the male beetle only and the tube is con¬ 
structed by him alone. The wax is secreted by a group of numerous 
minute pores situated in the apical third of each elytron. The fine 
glossy strands of wax lie flat on the surface of the elytron in a close 
band which curves in a right handed spiral and overlaps to form a 
small white disc about *35 mm. in diameter completely concealing 
the group of pores (Plate I, fig. 3x20). Mr. Puran Singh, Chemical 
Adviser to the Forest Research Institute, who kindly examined these 
tubes, informs me that the wax is probably an ester of ceryl alcohol. 
As soon as the construction of the entrance tunnel has made some 
progress, i.e.,has reached a length of 1\ to 2 inches, the secretion of wax 
by the male begins. The tube, examined under a high-power lens, shows 
an imbricate structure due to rows of overlapping wax-scales. It is 
evident, therefore, that the beetle detaches the scales at intervals as soon 
as they are fully formed, and presumably moulds them into the walls 
of the tube by rotary movements of its body. One or two weeks 
is required to complete the construction of the tube, after which the 
secretion of wax ceases and is apparently not renewed if the tube should 
get broken, or crack, as it often does in the late stages of the develop¬ 
ment of the brood, owing to expansion of the bark layer. 
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