10 : ROYAL SOCIETY OF CANADA 
Prof. Riley of the small Australian Lady-bird beetle ( Vedalia cardinalis), 
with the object of destroying an injurious scale insect, which was work- 
ing great havoc in the California orange-groves. The Fluted Scale, 
otherwise known as the “ White” or ‘ Cottony-cushion Scale” (Jceryia 
purchasi, Maskell), is, for its family, a large species, which was probably 
introduced into southern California about 1868, and, having reached 
the groves of citrus fruits, spread rapidly and increased so enormously 
that at the end of twenty years it not only had attracted universal 
notice by the extent of its injuries, but was the cause of great alarm. 
All efforts to control this insect seemed ineffectual, owing chiefly to its 
power both of living on a great variety of food-plants and of surviving 
for long periods without any food at all. Prof. Riley in 1886 directed 
his attention especially to the subject of discovering a practical remedy 
for this insect, and, having convinced himself that it was indigenous to 
Australia, and having also observed that it only occurred there in mod- 
erate numbers, he concluded that there must be in its original home some 
natural parasite which was keeping it in check there and preventing it 
from multiplying to the injurious extent to which it was occurring in 
California. A recognized rule in practical entomology is that when a 
foreign insect is introduced into a new home and increases excessively, 
this is due not only to the suitable conditions it finds in its new home, 
but particularly to the fact that its own special parasites are not as a rule 
imported with it. It is true that frequently the parasites of allied species 
of insects gradually acquire the habit of depredating upon the newcomer, 
but this takes some years, and may be only partially effective or not take 
place at all. It was noticed that some of the native predaceous Califor- 
nian insects were attacking the Fluted Scale to some extent, but Prof. 
Riley urged that greater success would be secured by importing from 
Australia its own natural enemies. After much trouble, this plan was 
satisfactorily carried out, through the skill of Mr. Albert Koebele, who 
was sent to Australia by Prof. Riley in 1888, and succeeded in sending 
home safely to California several consignments of parasitic and preda- 
ceous enemies of the Fluted Scale. One of these, known as Vedalia car- 
dinalis, a small Lady-bird beetle, has more than answered all the expect- 
ations of its introducers ; for, in the short space of one year and a-half 
from its first introduction, it has practically cleared out the injurious 
Fluted Scale throughout the infested region. It increases with surprising 
rapidity, taking only a month from the time the eggs are laid until the 
perfect beetles appear. The females lay a large number of eggs, and, as 
far as is known, it feeds exclusively on the Fluted Scale. Prof. Riley, in 
relating the history of this experiment, says: “The expression of two 
well-known people may be quoted here to illustrate the general verdict. 
Prof. W. A. Henry, director of the Wisconsin Agricultural Experiment 
Station, who visited California in 1889. reported that the work of Vedalia 
