80 
THE MEDITERRANEAN 
NATURALIST 
as the assertion may appear, it is nevertheless, 
a fact, that now ithstan ding the scientific methods 
that are now employed in the cultivation ni 
plant life, that both the number, mid the so\ 
rity of the diseases that the modern agriculture list 
has to combat, are much more formidable t i • , • ■ 
those with which his predecessors v, ere tn mbhi !. 
The system of unduly forcing, and of over ibri ii 
sing the plants is in a great degree answerable for 
this, for by creating conditions that arc. opposed to 
the natural processes, the plants are thus predis- 
posed to diseases, which as time passes, get 
more varied iu their forms, and more in! mi if • 
in their effects. 
The modern systems, too, often interfere with the 
balance of Nature by destroying not only tic 
injurious insects, but also the parasites, birds, and 
animals that are their natural foes, an that 
would, if not interfered with, tend to keep Ac e 
scourges in subjection. 
The rapid means of transit that now exist 
between different parts of the world, and the 
extensive interchange of commodities that, un in 
rally follows are also instrumental in fos'ering 
and disseminating disease. It was thus that the 
scale insect Icerya purchasi , which made so •]; 
havoc in the orange groves of Cape Colony a b -' 
years ago, found its way among the Californian 
fruit trees; and it was thus that the Hessian -tiy 
was transported from the United States to the 
cultivated regions of Europe. 
The devastation that insect pests have wrought 
during the last thirty years has not been con- 
fined to any one family of plants, or to any 
special region of the globe; though certain 
families appear to have suffered more severe 1 ;/ in 
particular localities than in others. 
Judging from the stastistics that have boon 
given to us by such authorities as Hubbard of the 
United States, and Miss Omcrod of Cape Colony, 
the Mediterranean fruit in general, and the orange 
in particular, is more liable to disease than is 
the fruit of Florida, California, Cape Colony or 
any other great fruit growing centre. 
The reasons for this incongruity will be more 
apparent after a brief consideration of some of the 
most common of the forms of disease. 
An abnormal condition of the Mediterranean 
orange plant is invariably marked by unmistakea- 
ble evidences of disease, of which the splitting of 
the fruit, the searing of the leaves, and the con- 
stant falling of both leaves and fruit from the tree 
are of the most frequent occurrence. 
As a rule, such signs as these are but the premo- 
nitory symptoms of worse evils; but, if they be 
but properly and methodically treated, a tempo- 
rary cure may be effected. 
This form of disease is of frequent occurrence 
in the orange groves of Malta, Sicily, Barbary, 
and Italy, where the equable climatic conditions 
that prevail, tend to promote the longevity and 
the propagation of the parasites ( Hciniptcm) to 
win 
>in the misc 
hi id- 
is du< 
Though they 
ai t* 
in- 
vet< 
mate encmh 
's to 
the n 
ICC 
dy bug ( Dart 
flu/U 
u< ), 
ano 
ther orange 
SCO 
•urge, 
y< 
jt the havoc 1 
hat they 
ere? 
ite by puuct 
‘ii pin 
ig the 
f 
ruit and cuusi 
ng it to 
rot. 
and fall to 
the < 
grown 
I, 
is often so gr< 
eat ai 
s to 
rieci 
essitate the 
rub’ 
iption 
o; 
f drastic met) 
is 
for 
thei 
r extermina 
tion 
F 
or some vet 
irs } 
iast, o 
on 
siderable dam 
mge 
lias 
heei 
n d me in Si 
cily 
and Ii 
tal 
y by the rava 
iges ( 
>f- a 
spec 
fies of bark- 
lice 
know] 
as the Mealy- 1 
bug. 
It 
belc 
ings to the s 
sub-i 
familv 
c 
f necinct ', and i 
■ pro 
pa- 
gate 
58 its species 
; wit 
h sue) 
l r 
apidity that th 
ic leaves 
of tl 
he infested 
tree 
s are 
r; 
tpidlv covered 
with a 
dirt 
y, white tic 
ICCIll 
ent iv 
lat 
ter in which 
the e 
| are laid and hatched. The fruit of the trees, that 
are. so attacked, never come to maturity. 
Another mite that is equally dreaded, and which 
is exceedingly common in Sicily, is the orange 
louse Ca/uindium citri. 
Its presence many be known by the peculiar 
white substance with which it encrusts the 
leaves, and by the black fungus which grows 
whomever the adult ejects the honcydow that it 
secretes. It is this black fungoid growth that 
gives tlie sooty .appearance to the leaves, which 
is so characteristic of this disease. They arc 
exceedingly destructive in their habits; and no 
kind of fruit is free from their attacks. Their 
fecundity is enormous, it being estimated that 
every female produces from 200 to 500 young; and 
the young mature, and produce a new brood in 
about three months. 
In the Malta and Sicilian orange, the smut 
fungus often extends to the fruit itself and makes 
a brownish ring on the outer skin, which gives 
to the orange the appearance of a russet apple. 
Th s is, however, n >t to be confounded with the 
d sease which is caused by the rust mite. 
The rusty appearance, that many oranges have, 
especially those from Sicily, is due to the presence 
of minute parasites ( TyphUnlromus ohimrux) 
which embed themselves in the epithelial cells of 
the outer rind of the fruit, in such numbers, as 
to impart to it a rusty, brownish colour. This 
disease is very common all round the Mediter- 
ranean. It neither affects the growth nor the 
quality of the fruit to any appreciable extent; 
yet the unsightly appearance that it causes the 
oranges to present, lowers then commercial value 
in the market. 
Of the scale insects, the most dreaded both 
in the orange groves of the Mediterranean, 
and the coffee plantations of Arabia is the 
mealy-bug. Dactt/lopins destructor was the chief 
cause of the ravages in the orange groves in 
Italy, and Southern France in 1806, (L’Abbe 
Loquez); and from the records that have since 
been kept, it is to be held accountable for much 
of the mischief that, is now being done. 
It usually deposits its eggs on the under side 
of the leaf, from whence the young larvae spread 
in all directions, soon after they are hatched. 
