chap. cv. coryla'cejE. ^ue'rcus. 1819 



small solitary leaf-rollers (TVSrtrix viridana Haworth) : for one of this sort 

 seldom consumes more than four or five leaves, if so much, during its exist- 

 ence. The number, therefore, of these caterpillars must have been almost 

 beyond conception ; and that of the moths, the previous year, must also have 

 been very great; for the mother moth only lays from 50 to 100 eggs, which 

 are glued to an oak branch, and remain during the winter. It is remarkable, 

 that, in this wood, during the two following summers, these caterpillars did not 

 abound." {Insect Transform., p. 203.) The moth (c) varies in the expansion of 

 its wings from 7 to 13 lines : the anterior wings are pale green, with a whitish 

 margin in front ; and the posterior wings brownish. It is so extremely abun- 

 dant, that, towards the end of the month of June, when it first appears, it 

 may be shaken from the trees in perfect showers. The caterpillar (a) of this 

 moth rolls up the oak leaves in a very ingenious manner, so as to form a very 

 commodious retreat; in which, indeed, it ordinarily resides, the centre of the 

 roll being open : its diameter is proportionable to that of the body of the 

 insect; and the roll is secured by various little packets of silk attached to the 

 body of the leaf, and to the adjoining part of the roll, as represented in 

 j%. 1647. at b. Reaumur, in the second volume of his Memoires, has given a 

 very detailed account of the manoeuvres employed by the caterpillars in the 

 construction of these leafy rolls. These caterpillars were so numerous in 

 Kensington Gardens in May and June, 1832, that "the excrementitious matter 

 from them kept falling and tinkling on the grass below, so frequently as to 

 give the idea of a sprinkling of rain being then falling." {Mag. Nat. Hist., v. 

 p. 671.) Millions of small lead-coloured caterpillars, tinted with green, and 

 slightly hairy, were then some of them half an inch long, and depending on 

 threads stretching to the length of 7 ft. or 8 ft. In some cases, a colony of 

 fifty or a hundred of these insects appears to set off all at once from some point 

 in a branch, and each to make the best of his way to the earth, the threads 

 diverging into numerous different lengths, apparently according to the age and 

 vigour of the caterpillar. At Haslemere, in 1830, 1831, and 1832, the ravages 

 committed by this insect were so great, that whole woods of oaks were stripped 

 of their leaves, and looked as if blighted by lightning. Each tree was " covered 

 with the remains of skeleton leaves, curled up, and surrounded with a filmy 

 web : its trunk and branches had a misty appearance, as if enveloped in white 

 gauze; while here and there hung suspended a long web, or a caterpillar that 

 had not yet found a habitation for itself in which to undergo its final change." 

 {Ibid. y p. 670.) This insect is the same as that noticed in Brown's edition 

 of White's Selbome, p. 311., in a note of the late Mr. Markwick. In the 

 Gardener's Magazine for 1829 (vol. v. p. 610.), a writer, describing the ravages 

 of this insect on the oak woods in Wales, says the coppices appeared to be 

 all alive with them, so immense were the masses they formed. These insects, 

 notwithstanding their numbers, appear, in their moth state, to have many 

 enemies. White says that he saw a flight of swifts busily employed in 

 " hawking them ;" and, in the Magazine of Natural History (vol. v. p. 670.), it 

 is stated that the .E'mpis livida, an insect of something less than their own size, 

 fixes on them, " something in the manner that a stoat would on a hare or rab- 

 bit," and flies about with its victim, but never lets it go till it has destroyed it. 

 Amongst the Butterflies, Thecla quercus, or the purple hair-streak, is the 

 only species which feeds upon the oak in the larva state : its caterpillar is 

 small, and bears considerable resemblance to a woodlouse, being one of the 

 onisciform larvae. One which M. Lyonnet {Recherch. sur V Anat., fyc. y de differ, 

 Especes d'Insectes, 2 me part. pi. 36.) reared ceased to eat on the 1st of June ; 

 it then assumed a rounded form, and in three days arrived at the chrysalis 

 state, without spinning any cocoon ; and on the 27th of the same month 

 the butterfly appeared. In its final state, it is an active elegant insect, 

 sporting about the highest twigs of the oak. It is about 1^ in. in the 

 expansion of the wings, which are of a bluish black on the upper side in the 

 males ; but in the females they are black, with a rich glossy blue disk. Owing 

 to their smaller size, and more brilliant colouring, the females have been by 



