November 30, 1882. ] JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 507 
The Chairman, Mr. Richardson, Curator, Botanic Gardens, the 
Secretary, Mr. Glover, and the Committee are to he congratulated 
upon the able and thoroughly successful manner in which the ar¬ 
rangements of this fine Exhibition were carried out. 
SILKWORMS AND SILKWORM REARING.—20. 
(Continued from page 461.) 
Amongst our native insects which have become more rare of 
late is the handsome moth to which has been given the appella¬ 
tion of the “ Emperor ” (fig. 85), although it is by no means the 
largest British species of the tribe, nor, indeed, can it be said to 
be the most beautiful. Yet this moth, Saturnia Carpini, certainly 
does offer to the eye a pleasing combination of colours, its eye-like 
spots suggesting its kinsmanship to the large foreign Bombyces 
that have .recently passed under our notice. It is to heaths and 
patches of straggling wood that the caterpillar (green, with black 
or pink warts), has generally been attached, and the clearing of 
ground for cultivation during the last fifty years has not favoured 
the increase of S. Carpini, which is now confined to a few localities. 
The cocoon is of silk, and rather curiously shaped, but it could 
not be turned to any use ; I doubt whether it could even be 
carded. 
This insect I mention, however, because the larger 
Saturnia Pyri, native of some districts of France 
and of other countries with a warmer clime than 
ours, has been placed amongst the possible pro¬ 
ducers of a textile silk. In bulk it far surpasses 
our “Emperor” (fig. 85), and, as may be ima¬ 
gined, the brown or grey of the wings shows up 
strikingly the complex spots by which they are 
adorned. The caterpillar or silkworm is very large, 
of a light green tint, studded over with dark blue 
tubercles, from each of which rise seven radiating 
hairs. It is not difficult to rear, feeding upon 
Apple, Pear, Plum, Ash, or Elm during July and 
August, and forming its cocoon in the latter month 
or September. This is of brown silk, in texture 
very strong, which might be made useful by carding 
it if produced in sufficient quantity. The moths 
emerge to lay their eggs in May or June, there being 
but one annual brood. A few attempts have been 
made to keep these upon the Plum in the open air, 
but our cold nights are rather against them, and 
in spite of their hairs they also fall a prey to the 
irrepressible sparrows. One observer has noted 
that the birds seem to like these foreigners quite as 
well as our native caterpillars, excepting indeed A. 
Cynthia and Prometheus, which were regarded with 
dislike, seemingly, by birds, though they did not 
escape spiders. These destroy some seasons many 
young caterpillars of various species. 
There is an insect named Ceratocampa imperialis 
which has been placed amongst the silkworms. 
It is an American species, and in its moth state 
remarkably beautiful, and of interest to those who experiment 
in caterpillar-rearing, though the cocoons are not of ascertained 
value. In expanse of wing it is from 4 to 6 inches, the males 
being smaller but more showy. The colouring is unlike that 
of the moths familiar to us in these islands, for the yellow ground 
is covered with small deep brown dots, and there are numerous 
spots or patches of red, with a purplish gloss upon them. It had 
been stated in the “Naturalist’s Library” that the rare cater¬ 
pillars of this species are seldom reared successfully, and if they 
reached maturity they generally died soon after entering the 
chrysalis stage ; but M. Wailly of Clapham reports favourably 
as to those he had in 1881. Eggs laid during July produced 
young worms early in August; these were kept in a house under 
glass, but well ventilated. Their growth beiDg slow would ac¬ 
count for their passing through as many as six changes of skin, 
two beyond the usual number amongst silkworms, and it was 
about the middle of October when they ceased feeding. M. Wailly 
describes the caterpillars as varying much in colour, from yellow 
to nearly black ; they exhibit five horns, which are studded 
with sharp points and forked. As the caterpillars increase in 
size these horns become shorter; they are not apparently used 
for weapons of offence. In habit this insect is not unsociable 
while in the larval stage, since M. Wailly remarks that “ they 
crawled over each other’s backs without showing the least sign 
of spite or animosity, even when they were in sleep, in which 
case larvae are generally very sensitive and irritable.” The co¬ 
coon is made beneath the surface of the earth, and the chrysalis 
reposes therein until the following summer. 
In addition to what has been previously stated with reference 
to Attacus Yama Mai, the Japanese silkworm of the Oak, and to 
A. Pernyi, the mountain species of North China, the following facts 
should be here noted ere concluding. A rather successful method 
of treating the newly hatched Yama Mai worms has been that of 
placing them under large bellglasses having a few openings in 
the dome, the food being kept fresh by putting small branches of 
Oak into saucers full of sand covered with paper. Any that may 
drop off the branches can without much difficulty be removed 
from the paper, and if kept out of the direct sunshine the leaves 
remain undried for several days. In this arrangement the branches 
must necessarily be cut short, but when these silkworms are fed 
upon branches plunged in water they must be cut long, otherwise 
the foliage would absorb some water into its natural juices, and 
this proves highly injurious to the worms ; yet, as already shown, 
they do not object to—in fact, rather like—moisture apart from 
the leaves. The Oak being a somewhat backward tree in most 
seasons, in anticipation of the hatching-out of Yama Mai some 
naturalists have placed young Oaks in pots, and by protecting 
them through the winter have brought them into leaf rather early, 
putting the worms upon them with a covering of gauze. But 
forcing Oaks by artificial heat has not been found to answer. 
There is a risk, however, of losing some through the getting 
chilled if the worms are kept out of doors before June is well 
advanced. 
Attacus Pernyi was reared several times in the open air some 
years ago, but the summer of this and of last year did not seem 
congenial to the worms when they were exposed upon Oak bushes 
to the changes of the weather. Near Colchester about ten years 
since a naturalist liberated a large number of fertile females in a 
somewhat retired wood. Subsequent investigations disclosed a 
few of the silkworms there, the progeny of these, and several were 
left upon the Oaks to attain their full size. No moths were ob¬ 
tained afterwards, or worms discovered the next season. The 
young Pernyi do not hatch so soon as Yama Mai—generally 
towards the end of June or in July, when there is abundance 
of Oak in good condition, a circumstance much favouring their 
rearing with success, and they evidently suffer little from 
diseases. 
Hereafter it is possible that much may be attempted in the 
way of crossing one species with another. As yet such experi¬ 
ments are in their infancy. Attacus Roylei, the Himalayan species 
of silkworm, also a feeder upon Oak, shows affinities for A. Pernyi, 
and a hybrid breed has been obtained from the two. The worms 
have all the good qualities of the North China parent, and the 
cocoon is preferable to that of A. Roylei, where so much of the 
strength of the spinner is expended upon the loose outer cocoon 
that the inner is thin and poor. From the hybrid has been got a 
compact cocoon and of better colour than that of A. Pernyi. We 
may yet be able to pair some species with the Japanese A. Yama 
Fig. 85.—Saturnia Carpini. 
