94 DESTKUCTIVE INSECTS OF VICTORIA : 



between the ladybird and the blight, and both of them 

 are always present ; but in New Zealand the ladybird, 

 being as it were in pure cultures and undisturbed by the 

 presence of any secondary parasites, is much more 

 powerful than the scale, and it completely wipes out the 

 latter. It is not too much to say that within another 

 twelve months there will scarcely be a living scale found 

 on the southern plantations, which only three years ago 

 were swarming with the pest, and to all appearances 

 doomed to utter destruction." 



The above is a most satisfactory state of affairs so far 

 as New Zealand is concerned, but in Australia the con- 

 ditions are, of course, very different, as in most of our 

 Victorian forests, at any rate, Gum Trees (Eucalypts) 

 largely predominate, and in some parts of the State the 

 arboreal vegetation is composed of but very little else ; 

 whereas in New Zealand the number of Eucalypts is very 

 limited, and are, of course, introduced from Australia and 

 Tasmania. So it happens that, although both the Rhizo- 

 bius and Crypolcemus are indigenous to the State, the close 

 proximity of our plantations to infested forests consider- 

 ably reduces the valuable work of these parasites. 



The plate shows nearly the whole life history of this pest y 

 together with some of the parasites, especially the valuable 

 little beetle Orcus, also cocoon of Scale-destroying Moth,. 

 Thalpochares. Many years ago, a friend and myself con- 

 ceived the idea that the cochineal-like dye from these 

 insects might be put to some commercial use, but the 

 advent of the aniline dyes quite upset our well-intended 

 project. Upon examining a badly -infested gum branch, 

 especially when the same has grown in a natural forest, 

 large quantities of the sacs will be found to have been 

 quite destroyed by parasites of many kinds, but it is 

 evident to any unprejudiced person that in Victoria, at- 

 any rate, parasites are no match for the scale, although 

 the former help materially in keeping it and other scales* 



