1S77.] 
VINES AND VINE-CULTURE.-CHAPTER XIII. 
267 
development: that is, those parts of a vinery which are not well ventilated will be 
more subject to red spider than the freely-ventilated parts. It follows, therefore, 
prevention being better than cure, that as dryness is the chief cause of its appearance, 
so moisture and water properly supplied ought to prevent it—and it is so. Hence 
we may deduce the following rules:—Water freely, and keep the atmosphere at 
all times thoroughly moist, especially if the temperature be high. If these points 
are attended to, little injury from red spider need be feared in the case of vines 
otherwise healthy. If unfortunately it does obtain a footing, water must still be 
the chief agent with which to compass its destruction; therefore, syringe freely 
with clear rain-water ; also apply sulphur to the hot-water pipes, or dust the 
leaves over with sulphur, &c., or wash them with soapy water, a decoction of 
quassia-chips, or any compound of sulphur and soap. These remedies, applied 
with perseverance, will be sure to destroy it. 
The Thrips {Thi'ips mimitisshna). —Fig. 2 shows the thrips much enlarged. It 
is a small, long, slender insect, of a dark brown colour, sometimes pallid or almost 
white, which is oft-times to be found feeding upon the leaves, much in the same 
manner as the red spider. The thrips is, however, not nearly so generally to be 
found on vines as is the red spider, and would rather appear to be introduced to 
the vineries from other plants ; but its ravages are much more severe where the 
insects are permitted to establish themselves, and they spread rapidly. A dry atmo¬ 
sphere is favourable to their increase, and in like manner water is inimical to 
them, but they can scarcely be dislodged or destroyed by any amount of mere 
syringing. It is necessary to wash the leaves with soap and sulphur, or to give 
them a good dressing with tobacco-powder, or some insecticide, but it must be 
directly applied to them, or it will be of little avail. 
The Mealy Bug {Bactylopiiis adonidiim ).—An insect of foreign introduction, 
but now, unfortunately, very common in our plant-houses. It seems to be at 
home on most plants, and so the vine does not escape it. The mealy-looking sub¬ 
stance which covers the body of the insect (fig. 3) 
is an excretion, and gives rise to the name of mealy 
bug. Its presence ought to be rigorously guarded 
against in the vinery. No plant with any bug on it should 
ever be taken into a vinery, for if once introduced, it is 
scarcely possible to get rid of it again. It increases very 
rapidly, and in the thick, rough bark of the vine it finds 
at all times a secure hiding-place, so that in winter, be the 
vines dressed ever so carefully, some are almost sure to 
escape, and spread from branch to leaf and fruit bunch, and 
when on the latter, they cannot be destroyed without damag¬ 
ing the berries. We have seen many crops of grapes so 
destroyed. All that can here be recommended is the 
utmost care in not allowing the insect to be introduced. To 
z 
