618 
above-mentioned crops. This line of work 
had its origin at the California State In- 
sectary, together with the process of 
hibernating this and various other species 
in enormous quantities in artificial cold 
storage. 
Experiments have been conducted along 
this line at the Insectary, whereby the 
Hippodamia convergens has been success- 
fully kept in hibernation in cold storage, 
without impairing the vitality of the spe- 
cies for seven months and 14 days. 
This particular line of work was in- 
augurated through practical necessity, ow- 
ing to the fact that the chief obstacle to 
the raising of cantaloupes in California, 
especially in Imperial valley, has been the 
attack of the melon aphis (Aphis gossy- 
pii), often ruining whole fields in three 
or four days, and no mechanical or other 
means of fighting them had been found 
effective; indeed, it was only possible to 
get rid of them by destroying the infested 
vines. 
The use of ladybirds for the destruction 
of aphids has gradually spread from their 
be 
Fig. 8. Pounds of 
Ladybirds on Pack Mule. Nine miles through 
the snow to the packing house. 
One Hundred and Thirty 
originally appointed work, until now the 
Insectary ships crates upon crates to prac- 
tically every county in the state of Cali- 
fornia, and to growers of almost every 
horticultural product subject to the attack 
of aphid species, even including city (or- 
namental) street trees and home gardens. 
The particular coccinellids (Hippodamia 
convergens) used in fighting aphid infest- 
ations are a species native to California. 
They are of a predatory habit, and their 
special prey and chosen food are the 
aphids, upon which they feed both in the 
larval and adult stages. 
The best results are obtained by placing 
colonies in the infested fields or orchards 
at, or just before, the first appearance of 
the aphids; the object being to prevent 
the increase of these destructive insects. 
Again, the female coccinellid, if the 
natural food is scarce in an orchard or 
field, is thus forced to search diligently 
ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 
for aphids, and will distribute her eggs 
in proportion to the number of aphids 
present; whereas, if the colonies were not 
placed until after the aphids had become 
abundant, she would deposit practically 
all her eggs in the samé place. The same 
rule will apply to practically all cultivated 
crops, and therefore it is important that 
applicants for colonies of this particular 
species should place their order early, and 
again notify the Insectary when the very 
first aphids are noticed, and ask that their 
colony be sent them immediately. 
It has been thoroughly demonstrated 
that by following such a procedure, with 
the help of the ladybirds, orchards and 
fields have been kept commercially clear 
of this obnoxious insect. So great is the 
demand for ladybirds by growers of 
melons and all other kinds of fruit, that 
the Insectary has been obliged to organ- 
ize, upon a very considerable scale, the 
work of collecting these insects. 
The enormous amount of work con- 
nected with the locating, collecting and 
holding in hibernation, the boxing, crat- 
ing, shipping and distributing of several 
tons of live insects is little realized by 
the average reader. The _ illustrations 
accompanying this article, together with 
the following, will give some idea of how 
this work is conducted: 
Starting about November ist, the field 
men go up into the mountains to locate 
the hibernating colonies, which are usual- 
ly found among pine-needles on sunny, 
well-drained slopes, usually in close prox- 
imity to running water. They are se- 
curely hidden, and inexperienced collect: 
ors may pass and repass directly over 
such spots and the presence of the colony 
will never be detected. In fact, the idea 
generally prevails in the minds of the 
mountain residents that the beetles come 
to the sections in the spring, and the 
idea is scouted that colonies of beetles 
spend the winter under the snow. 
At this season, however, only a few of 
the beetles, relatively speaking, are dis- 
coverable. They are the first arrivals 
which have sought winter quarters early, 
but later on the colonies thus started 
rapidly grow in size. Other ladybirds 
join them, probably attracted by a pecu- 
liar insect odor, which they recognize, 
and so in the course of a few weeks im- 
mense numbers assemble. 
Just how these over-wintering colonies 
are located, if explained, would hardly be 
believed by the general reading public. 
In fact, it is a sort of sense that is hardly 
subject to analysis. Our field men know, 
by past experience, where the most likely 
places are, and how also to find the bee- 
tles. We can at least immediately tell 
where they are not, thus eliminating a 
great deal of unproductive territory from 
