CHAP.’ XLII. ROSA‘CER. ROSA. 811 
tionary measure have been neglected, care should be taken to watch for the 
appearance of the first brood, and, as soon as the insects are perceived, to 
destroy them with lime or tobacco water, or by fumigation ; taking care never 
to use the nearly boiling water after the buds are expanded, though it will not 
do the slightest injury before that period. Each succeeding brood being 
much more numerous than those which preceded it, is more difficult to 
destroy ; till the summer broods, if suffered to appear, completely clothe the 
young shoots, so as to make them seem nearly three times their natural thick- 
ness. In this state, the best remedy is to put 3 |b. of the best strong tobacco 
into a gallon of hot water, and, as soon as the infusion has become cold, to dip 
the young shoots into it, letting them remain a few seconds in the water, and, 
if they are in a very bad state, going over them a second time. After this the 
shoots should be carefully washed with clean water, and the insect will 
generally be found to be destroyed. (See Gard. Mag., vol. x. p. 215.) | Choice 
plants may be freed from the aphides by going over the whole plant with a 
soft brush ; laying the infected shoots in the palm of one hand, and brushing 
off the insects with the other. Pruning is of little use, as the aphides 
generally attack all the young shoots of a plant at the same time. (See Encye, 
of Gard., edit. 1835, p. 1076.) The plants may also be syringed with water 
in the evening,.and then dusted with powdered tobacco leaves, or refuse 
snuff; or they may be syringed with lime water. The prodigious fecundity of 
the A‘phis rosze almost surpasses belief. ‘ Reaumur has calculated that, in 
five generations, one aphis may be the progenitor of 5,904,900,000 descendants ; 
and in ordinary seasons, there are ten generations produced 
on rose bushes in the space of nine months.” (See Hncyc of 547 
Gard., p. 1076.) 
The larva, or grub (fig. 547. 6), of the lady-bird (a) should 
always be spared by gardeners, as it lives on the aphides. 
This grub is short and thick, of a blackish purple, spotted 
with yellow or black, and is very active. A few of these 
insects would soon clear a tolerably large rosarium of thie 
aphides. The larve of. several flies (Syrphus Fr.) (c) are 
furnished with a singular mouth, armed like a trident, with 
three points, for.transfixing their prey, of which they devour 
amazing numbers. Small singing birds also destroy great 
numbers. 
The caterpillars of several small moths, though not so destructive as the 
aphides, also materially injure the buds and young shoots of rose trees. One 
of these is of a green colour, with a few black hairs scattered on its body: 
it sews up the tender leaves by means of silken threads, and takes its station 
within, concealed from all observation. The leaves of the rose tree are often 
marked, in autumn, on their upper surfaces, in various directions, with broad 
brown lines, leaving a narrow black one running down the middle. This 
curious appearance is produced by the small caterpillar of a minute moth 
(Microsétia ruficapitélla Steph.), which feeds inside the leaf. The caterpillar, 
when full grown, is nearly two lines long, and of a yellow orange colour, with 
a brown mark down the back. It lives upon the thickness of the pulp under 
the epidermis ; and the brown mark is caused by the epidermis drying, in con- 
sequence of the insect having eaten the substance of the leaf beneath. The 
black mark is produced by its egesta, or excrement. The caterpillar is full 
grown about the 24th of October, when it eats its way out of the leaf for 
the first time, and crawls down the branches and stem, until it has found a 
convenient place to fix itscocoon. The perfect insect is called the red-headed 
pygmy by Haworth; and it is so small, that the expansion of its wings mea- 
sures only two lines and three quarters. (Jdid.) 
Others, and perhaps the most destructive, of the insect enemies of rose 
trees are the caterpillars, grubs, maggots, or larvae, of one of the saw fly tribe 
(Tenthredinidz), which, when full grown, just before they change into the 
pupa state, are about half an inch long, and of the thickness of a crow-quill, 

