Part I] Lindsay and Harlow : Lac and Shellac 11 
of its difficulty, although it is of very great practical importance. 
This question of physiology—namely, what is the nature of the 
transformation that goes on inside the insect’s body—lies at the 
root of the whole matter. When we have found out how the insect 
makes its lac and what raw materials it uses, we may begin to 
stimulate its production and control the quality of its produce; but 
until the physiological question is tackled, no confident advance in 
these and many other directions is possible, and this is the point 
on which attention should primarily be focussed in the event of 
biological research on lac being undertaken. 
Another biological enquiry of much importance is that relating 
to the enemies, parasites and diseases of the lac insect and its food 
plants. In the case of the insect, there is a good foundation for 
this study in the work of Imms and Chatterjee, who have described 
some of its more important enemies. The most destructive of these 
are the caterpillars of three or four species of small moths of the 
genera Eublemma , Hypatina and Holococera , and a few small 
Hymenopterous (Chalcid) parasites. The Chalcid larvae probably 
consume the bodies of the living lac insect, while the caterpillars of 
the moths (Eublemma amabilis being the most notorious) 
apparently consume both lac and insect, riddling the lac with their 
web-lined tunnels. Some of the Chalcids may also quite possibly be 
“ hyper-parasites ” of the caterpillars, and therefore beneficial. 
Among those qualified to judge there is complete agreement as to 
the seriousness of the loss occasioned by these insects, though its 
actual magnitude cannot yet be estimated. Imms, who has devoted 
considerable attention to their study, believes the loss to be very 
large, and urges the importance of a more detailed investigation with 
the object of checking their ravages. He suggests a scheme for deter¬ 
mining whether the lac insect is the only insect that they victimize, or 
whether they have other hosts. The point is of prime importance in 
considering preventive measures, and an abstract of the scheme is 
given in the Appendix on “ Research.” 
Ants are believed by some to do serious damage to lac, and they 
are very frequently seen running about on it in a manner which looks 
suspiciously predaceous. It is probable, however, that they are 
merely licking up the valueless “ honey-dew ”, to which they are passion¬ 
ately attached; many other Coccidce besides the lac insect are attended 
[u] 
