28 Elementary Manual of Zoology. 
founded is that of the Scolytide, which differ both in the structure 
of the tarsi! and in the possession of moxe produced heads. The 
larvee of the Ptinide have legs, while those of the Scolytide are 
legless. 
Ptinide larve tunnel into dead-wood of all kinds and, like almost 
all other boring insects, prefer for their attack wood in which the 
flow of sap is not abundant, Bamboos in particular are specially 
liable to be attacked and are often reduced to little more than 
powder, Tke bamboo insect is a species of Dinoderus which makes 
burrows about 1°5 millimetres in diameter. The eggs are believed 
to be laid by the mother beetle, soon after the bamboo is cut. The 
larve are little white grubs with powerful mandibles, which gnaw 
their way through and through the bamboos, the injury often 
remaining unnoticed until the larve have transformed into pupe 
and the beetles begin to cut their way out. The best way to preserve 
bamboos from attack is to soak them in water for some time after 
being cut. This is said not only to prevent the deposition of eggs 
but to render the bamboos distasteful to the insect. For bamboos 
which have been thoroughly soaked in the first imstance appear to 
be seldom- attacked afterwards. Sponging bamboos over with 
kerosine oil is also an efficient prevention, when done early enough, 
but is only practicable in some cases. 
The well-known cheroot weevil (Lasioderma) and book-worm (Sitod- 
repa), which are such a nuisance in India, also belong to the Ptinide, 
while stored grain, opium and numerous other substances are attacked 
by members of the same family. In Europe one of the best known 
representatives is the “death-watch ” (Anodium), which is found in 
old furniture. The students_should sketch one of the largest of the 
Ptinidz beetles in the School Museum. They should also be shown 
bamboos attacked by the bamboo borer. 
Cantharide (Blister beetles).—This family of heteromerous beetles com- 
prises a number of brightly-coloured insects, the commonest of which 
(Mylabris) have the elytra banded with black and yellow stripes ina 
manner which tenders them easily recognisable. The beetles have 
been reported as doing a little damage in India as defoliators, but 
are not likely to be of much practical importance, The Jarve do not 
seem to have been observed in India, but in the case of the common 
1 The Scolytida ave said to have tetramerous tarsi while the Ptinide have pentame- 
rous tarsi. The basal joint in the Ptinide, however, is often so minute as to be difficult to 
make out, while the rudimentary penultimate joint in the Scolytide is sometimes visible. 
By remembering, however, that in one case it is the basal joint which is rudimentary and 
in the other the penultimate joint, this difficulty disappears. The two groups should be 
carefully distinguished, as they have somewhat different habits. They have become a 
good deal confused with each other owing to the looseness with which the name Bostry- 
chide has been employed by different writers. 
