631 
were it not for the beneficial forms, there would be very little, if 
any, vegetation left growing in this or any other Australian State, 
as there are thousands of indigenous species of insects which are 
held in complete subjection by other insects, and are unnoticed. 
It is only when an insect becomes a pest that any attention is given 
it, and it will be found that all pests are imported forms. It often 
happens that imported forms are subject to the attacks of indigen- 
ous forms, which accomplish a great deal in checking their spread, 
and the illustrations here shown, with one exception (Leis con- 
formis), are indigenous species, and should be protected. 
Leis eonformis, Boisd. Rhizobius debtlie, Blkb. Oreus Australasies (larva). 
These useful insects are themselves, in turn, attacked by para- 
sites and predaceous ones, so that they do not accomplish as much 
in checking the spread of imported pests as they would otherwise do. 
Cocetnella transversaits, Fabr. Lets conformis Boisd. 
Blastophaga grossorum.—It has been well demonstrated that 
without the aid of these little insects we cannot successfully produce 
the Smyrna fig of commerce, 
