Systematic Course, 51 
all her eggs in the case. In collecting bag-worms by hand, therefore 
as is often done upon tea gardens, where they doa good deal of 
damage, care should be taken to collect all the apparently dead cases, 
as these are always liable to contain eggs. 
The School Museum contains some larval cases of these insects. 
Hepialide group.—These creatures are to be found boring into live timber 
and do a good deal of damage to many forest trees in India, Like 
other wood-boring .larve, they have a firm cuticle and powerful 
mandible. They can be distinguished from wood-boring larve belong- 
ing to other orders of insects by the possession of the fleshy abdominal 
pro-legs which are characteristic of caterpillars. The group includes 
the families Hepialide, Cosside, and Aigeriide. The moths are very 
variable in their appearance, but the caterpillars are so closely related 
to each other, both in habits and in appearance, that it will be most 
convenient for the students to consider them collectively. 
In each case eggs are laid by the female upon the bark and the 
caterpillar tunnels into the wood. It usually keeps the tunnel open 
and often comes out to feed upon the bark. It frequently builds 
for itself a covered gallery of silk and excrement which forms a con- 
spicuous feature on tree trunks. The chrysalis is formed at the en- 
* trance of the burrow, so that the moth can readily make its exit. 
In Travancore, a few years ago, very considerable injury was 
done to teak trees by a large red boring caterpillar of this group. 
It was found to commence its attack on the wounds caused by 
lopping, and its effect was to let the moisture penetrate into the 
stem and induce rotting. Sandal-wood, coffee, and tea all suffer in 
a somewhat similar manner from the attack of an allied caterpillar 
of the species Zeuzera coffee, Nietner, Young poplar trees also in 
Baluchistan have been reported as injured to a very large extent by 
the species Sphecia ommatiaformis, Moore. The moth of the last 
species can be immediately recognised by its striking resemblance 
to a large wasp. The caterpillars tunnel into the poplar stems close 
to the ground and weaken the trees to such an extent that they 
are frequently blown over by the wind, Wood-boring caterpillars 
can be readily killed by squirting a little kerosine-oil into the hole 
which they make in the trunk, or by running a sharpened wire into 
it, but this treatment is only likely to be of use in the case of valuable 
fruit trees, 
The School Museum contains larve and moths of this group. 
The students should notice particularly both the pro-legs and the 
comparatively firmness of the body in the larve. 
Bombycide group.—The larve of most lepidopterous insects are able 
to spina certain amount of silk, but there are in India a number 
of species belonging to the families of Bombycide and Saturniid 
K2 
