PLATE XIII1. Clouded Yellow2. Pale Clouded
PLATE XIII
1. Clouded Yellow2. Pale Clouded
I wonder if you have ever seen this very handsome butterfly alive. Very likely you have not, for although just now and then it is very common indeed, it nearly always becomes quite scarce for several years afterwards, and you may look for it summer after summer without seeing it at all. It makes its appearance in August and September, and the best places in which to look for it are clover and lucerne fields near the seaside. But it is also very fond of flying about on railway banks; and if you try to chase itthereyou will find that you will have to run very hard indeed if you want to catch it! In fact, one butterfly collector used to say that it was of no use trying to do so unless one wore a pair of seven-leagued boots!
The caterpillar of the Clouded Yellow butterfly is of a bright grass-green colour, with a white line on each side, marked with yellow and orange. It feeds on the leaves of lucerne, trefoils, and clover in June and July, and then changes into a green chrysalis shaped something like that of a “large white,” with a pale yellow stripe on each side, and a number of black and reddish-brown spots.
Sometimes this butterfly is known as the Clouded Sulphur. It appears in the same places, and at the same time of the year, as the “clouded yellow,” but is hardly ever quite as common. Generally, indeed, you may see ten or twelve “clouded yellows” to one Pale Clouded Yellow. You can easily tell it by its much paler colour, for its wings are quite light yellow instead of rich orange, while sometimes one meets with a Pale Clouded Yellow which is really almost white. And, besides that, the black border of the upper wings, instead of being nearly the same width all the way along, is very broad at the top and very narrow at the bottom, while even in the male it is marked with several yellow spots.
This pretty butterfly is quite a seaside insect, and sometimes it may be seen fluttering over the waves a long way out from the shore. Indeed, there seems to be very little doubt that now and then it flies right across the Straits of Dover, and reaches this country from France!
The caterpillar of the Pale Clouded Yellow is olive-green in colour, sprinkled with black dots, and with two yellow lines along its back and another on each side. It feeds on clovers and trefoils.