Feb.] THE HOT-HOUSE. I75 
ing itself along the veins of the leaves, from whence it skips with 
great agility on being touched. It is a great enemy to the Vine 
while the leaves are young and tender, whether they grow in the 
open air or under glass. The Cape jasmine, as well as many other 
plants, often fall a prey to these minute insects. 
These may be destroyed by the same methods as the Aphis. 
4. The Oniscus, or Wood-louse. This belongs to the order Ap- 
tera. Characters — Antennae, setaceous and bent-mouth, furnished 
with two palpi. Head, intimately joined with the thorax. Body, 
oval-form, composed of several crustaceous plates. Feet fourteen. 
They change their skin like many other apterous insects. 
These are very common in the bark-pits, as well as in woods, 
houses, gardens, &c. but are seldom destructive, except to young 
seedling plants, on their first appearance above ground. This, how- 
ever, may be prevented by dusting the plants, whilst in that state, 
with fine snuff or tobacco dust. 
5. The Formica, or Ant. This insect is so universally known 
as to render a description unnecessary. 
These are often exceedingly numerous in Hot-houses, and espe- 
cially where the Aphides and Coccus hesfieridum abound; for there 
is a sweet glutinous matter which issues from these insects (being 
either their excrements, or produced by them from some other cause) 
that seems to be the principal incitement that draws the ant thither. 
The ant may be destroyed with great facility by setting pots con- 
taining honey and water, in the same manner as is practised for 
catching wasps, &c. 
6. The Coccus hesperidum, or Brown Turtle Insect, already 
described, is not an enemy only to the Pine-apple plant, but also to 
many others both in the Hot-house and Green-house; therefore, I 
am induced to take notice of it again. 
This insect may be destroyed, whilst young, by fumigation: there- 
fore, where that operation is frequent, they are rarely to be met 
with. 
Of Fumigating the House. 
The house may be fumigated either by means of bellows invented 
for that purpose, or by that of a smoking-pot. The most eligible 
seasons for this business, are the spring and autumn, when, if ne- 
cessity requires, it should be repeated every eight or ten days, till 
the proper effect is produced. But it may be done at any period, 
except when there are ripe fruit in the house, as then it would give 
them a smoky flavour. 
Fumigation is best performed late in an afternoon or evening, 
and proves most efficacious when the weather is moist and calm; 
for the smoke is retained much longer in the house when the air is 
still, and the cavities of the roof, particularly those between the 
squares of glass, filled with moisture. 
The Afihides may be destroyed with a gentle fumigation; but 
the Thri/is and Coccus hesfieridum require a smoke so strong, that a 
person cannot distinguish an object farther than at the distance of 
five feet. 
