PART

ARBORETUM ANI) FRUTICETUM.

2565

The number of inhabitants in a colony varies from 100 to 200; and, hence,the more numerous the colony, the more frequently is a change of residencerequired. These webs consist of a great number of threads, not unlike spiderwebs, arranged somewhat irregularly, but sufficiently loose to enable the in-habitants to be seen through the covering. The caterpillars eat only theparenchyma of the upper side of the leaf; they also arrange their threadslongitudinally, each, apparently, having a thread of its own, along whichit moves either backwards or forwards without disturbing its neighbours,which, when in repose, are arranged side by side. The larger-sized nestsinclude several of the smaller branches or twigs with their leaves; and someparts are of a firmer texture than the rest, apparently for resisting the wet.When the parenchyma of the upper sides of the leaves enclosed in the webhas been consumed, the nest is abandoned, and a new one made, enclosinga fresh bunch of twigs, each of the caterpillars spinning a considerable numberof threads; and thus each colony constructs as many as 6 or 8 distinct webs,disfiguring the tree, especially when, as is often the case, there are manysocieties established upon it. The leaves, thus half-consumed, wither up, aswell as the young branches, for want of support, and the tree assumes theappearance of having been entirely scorched up with fire. The caterpillarsrarely quit their nests; but, when alarmed or disturbed, they endeavour tomake their escape by spinning a long thread, and dropping to the ground.When touched, also, they writhe about with great activity, and will runbackwards nearly as fast as forwards.

“ When full grown, about the beginning of July, each caterpillar enclosesitself in a long and nearly cylindrical cocoon of white silk {Jig. 2464. d ), of

a leathery consistence; and these cocoons are arranged side by side at oneend of the nest, forming a mass not unlike, only considerably larger than,a mass of ants’ eggs, as the cocoons of the ant are commonly called. As thewhole of a colony has been reared from one brood of eggs, it is generally thecase that the entire number commence the construction of their cocoons atthe same time, and the whole are generally completed in the same day. Inthis cocoon, the insect immediately undergoes its change to the chrysalisstate {Jig. 2464. e); and its chrysalis, which does not materially differ fromthose of other small lepidopterous insects, is of a shining chestnut colour.It differs, however, from the chrysalides of the leaf-rollers, in wanting thetransverse series of hooks with which the abdominal segments of the latterchrysalides are furnished; and hence, when, at the expiration of about 20days, the perfect insect is ready to come forth, being unable to work thechrysalis out of the cocoon, the escape of the imago is effected within thelatter, and the moth, with its wings in an unexpanded state, makes its wayout of one end of the cocoon, after which its wings soon spread to their fullsize.

“ The perfect insect is shown at e in Jig. 2464., with its wings expanded,and magnified ; f is the same, with its wings closed, and of the natural size;and g, the caterpillar, rather magnified. — J. O. W.”

P. (c.) angustifolia. 909., dele the (c.).

Additional Species of Pyras belonging to the § M alus. 910.

“ P. ? Schotti Ledeb. There is a plant in the Horticultural Society’sGarden, received, under this name, from Dr. Ledebour.

“ P. stipulacea Hort. There are plants in the Horticultural Society’s

8 c 4