PARK AND CEMETERY. 
J 93 
the case. The bulletins of the Agricultural Department 
published by the United States government at Wash- 
ington and the reports of the entomologists of the differ- 
ent States are the most important literature on the sub- 
ject, and these can be obtained free bv applying for 
them. These, with Packard’s Guide to the .Study of In- 
sects, Comstock’s Manual, Harris’ Insects Injurious to 
Vegetation and Packard’s Insects Injurious to Forest 
and Shade Trees would form the nucleus of a good 
working library. While you cannot always succeed, yet 
you can do much to lessen damage, if not entirely pre- 
vent it. Many of our worst pests have been the intro- 
duced ones, and this may be partly explained by the 
fact that in most cases the native parasite has not been 
introduced with the pest; in such cases it is sometimes 
desirable to search out the parasite and introduce it, but 
this must always be done under the most intelligent su- 
pervision, lest other injurious pests be also introduced. 
One of the most striking examples of the introduction 
of a destructive insect is the case of the “Fluted Scale” 
( Icerya purchasi) into California on imported cuttings 
from Australia. This scale spread until the entire 
orange culture seemed doomed. Prof. Riley and his 
assistants investigated and found that while the scale 
had been brought here, its parasites had not been intro- 
duced with it. 
Sending an agent to Australia, a number of the 
parasites of the “Fluted Scale” were brought over. One 
of them, a small “Lady Bird,” called Vedalia Cardinalis, 
a very rapid breeder, attacked the scales with such 
vigor that it practically wiped them out in a few weeks! 
Bearing in mind the fact that every conceivable 
remedy had been tried on these “Scales” without suc- 
cess, and that many thousands of dollars had been 
spent, this result is one of the marvels of practical en- 
tomology. Mr. Wm. F. Channing of Pasadena, Cal., 
son of the eminent Unitarian divine, wrote: We owe 
to the Agricultural Department the rescue of our orange 
culture by the importation of the Australian “Lady 
Bird” ( Vedalia Cardinalis ). The white scales were in- 
crusting our orange trees with a hideous leprosy. They 
spread with wonderful rapidity, and would have made 
citrus growth on the whole North American continent 
impossible within a few years. It took Vedalia when 
introduced only a few weeks absolutely to clean out the 
“White Scale.” The deliverance was more like a mira- 
cle than anything I have ever seen. In the spring of 
1889 I had abandoned my young Washington Naval 
orange trees as irrecoverable, yet these same trees bore 
from two to three boxes of oranges apiece at the end of 
the season (or winter and spring of 1890). The conse- 
quence of this deliverance is that many hundreds of 
thousands of orange trees have been set out in Southern 
California. In other words, the victory over the scale 
was complete, and will remain so. It must not be 
thought that all cases of the action of parasites will be 
as successful in exterminating noxious pests, for such 
is not the case, while parasites undoubtedly control the 
excessive increase of a species and hold the balance even, 
yet in many cases their action is of no practical value. 
Among the beneficial insects the family of Coccinellidae 
or “Lady Birds,” as they are commonly called (to this 
family Vedalia Cardinalis belongs) are of first impor- 
tance. Their destruction of “plant lice” is wonderful. 
Were it not for these beetles the Aphides or “plant lice” 
would destroy all vegetation. I once had a cherry tree 
that was completely covered with “plant lice,” and the 
leaves curled and turned yellow. I thought the tree 
would surely be k i led, but in a few days the ‘‘Lady 
Bird” larva; clean id out the plant lice so completely I 
was unable to find a living one. Dr. Asa Fitch mentions 
a man who complained that his rose bushes were more 
seriously affected with “plant lice” than his neighbors, not- 
withstanding he conscientiously cleaned off the old par- 
ent “bugs,” having mistaken the beneficial “Lady Birds” 
for the parents of the “plant lice.” I saw a farmer near 
St. Bernard killing potato beetles by knocking them 
into a basin of coal oil. lie had also killed many of 
the 9-Spotted Lady Bird ( Coccinella g-Noia/a). I 
told him he was killing a friend when he included this 
“lady bird” in with the potato beetle?, but he replied 
that the “lady bird” was in bad company, and pro- 
ceeded with the killing. The introduction of a pest is 
very easy and frequently brought about in a curious 
manner. Some one (I never learned who it was) sent 
me several of the large European “Slugs” ( Limax Max- 
imus ) as a present. I was away from home at the time, 
and my housekeeper placed the tin box t ey were in 
out on a shed. A storm came up that night and the box 
was blown off and the “slugs” escaped, and Avondale is 
now populated with this nasty, destructive “slug.” 
Trouvelot, a silk culturist, imported into Massachusetts 
eggs of the Gipsy moth ( Ocneria Dispar ). Perhaps, and 
it is to be hoped unintentionally, a box containing some 
of these eggs was left standing on a window sill; it was 
blown out and Trouvelot was unable to find the eggs, 
and the result is that an area of over 200 square miles 
has been devastated by this terrible pest, and over seven 
hundred thousands of dollars have been spent in the en- 
deavor to exterminate it and limit its spread. It is ihus 
easy to see how an insect that may be comparatively 
harmless in its own country because of the natural par- 
asites that hold it in check, when removed to another 
locality where these parasites are absent soon increases 
so as to become a formidable scourge. 
There is much about natural history in the popular 
mind and printed in the newspapers that is mythical. 
The old legend of the hair from the tail of a horse turn- 
ing into a snake or worm yet finds some believers. The 
true history of the “1 air snake” or “worm,” or as natu- 
ralists call it, Goedius Atjuaticus, is very remarkable, 
even stranger perhaps than fiction. The hair worm de- 
posits its eggs in the water; these eggs hatch into min- 
ute swimming creatures provided with little hooked 
arms. When a grasshopper or cricket accidentally falls 
or jumps into the water one of these little baby hair 
worms fastens to it before it gets out and eats its way 
between the segments, feeds on the fatty parts just be- 
neath the skin without killing its host. When the hair 
worm is full fed the grasshopper must again get into the 
water or a damp place, when the hair worm again 
wriggles out to deposit its eggs and again go through 
the wonderful cycle of its transformat'ons. Its repro- 
duction depends first on the grasshopper getting into the 
water, becoming parasited and getting safely out again, 
remaining out long enough for the hair worm to become 
full fed and then getting back to the water to enable the 
hair worm to accomplish the purpose of its existence. 
While the hair worm perhaps does not very much reduce 
the number of destructive grasshoppers, yet it furnishes 
us with a marvelous instance of how nature works. The 
“grasshoppers” do not become such a very serious pest 
in this locality as they do in some parts of the west. 
Some years ago, while in Kansas, I was awed at the de- 
