Page:White - The natural history of Selborne, and the naturalist's calendar, 1879.djvu/436

414 in bulk, dart and shoot along on the surface of the water with the males on their backs. When a female chooses to be disengaged, she rears, and jumps, and plunges, like an unruly colt; the lover thus dismounted, soon finds a new mate. The females, as fast as their curiosities are satisfied, retire to another part of the lake, perhaps to deposit their fœtus in quiet; hence the sexes are found separate, except where generation is going on. From the multitude of minute young of all gradations of sizes, these insects seem without doubt to be viviparous.—.

Most of our oaks are naked of leaves, and even the Holt in general, having been ravaged by the caterpillars of a small phalæna which is of a pale yellow colour. These insects, though a feeble race, yet, from their infinite numbers, are of wonderful effect, being able to destroy the foliage of whole forests and districts. At this season they leave their aurelia, and issue forth in their fly-state, swarming and covering the trees and hedges.

In a field at Greatham, I saw a flight of swifts busied in catching their prey near the ground and found they were hawking after these phalænæ. The aureliæ of this moth is shining and as black as jet; and lies wrapped up in a leaf of the tree, which is rolled round it, and secured at the ends by a web, to prevent the maggot from falling out.—. I suspect that the insect here meant is not the phalæna quercus, but the phalæna viridata, concerning which, I find the following note in my "Naturalist's Calendar " for the year 1785.

About this time, and for a few days last past, I observed the leaves of almost all the oak-trees in Denn copse to be eaten and destroyed, and, on examining more narrowly, saw an infinite number of small beautiful pale green moths flying about the trees; the leaves of which that were not quite destroyed were curled up, and withinside were the exuviæ or remains of the chrysalis, from whence