CHAI’. cm.

SALICA'CE/E. ja'ux.

1483

moist ground, highly favourable in itself for the growth of osiers, planted it;and, after a few years, the osiers had disappeared, he hardly knew how.

It was planted a second and even a third time, and the plants always dis-appeared. “ My attention,” says the writer, “ being now strongly drawnto the subject, I discovered that which I ought to have perceived half acentury sooner; namely, that Nematus capreae, favoured by the peculiar lo-cality, was the cause of all this devastation. The spot is low, moist, shutin by wood, and very near the southern limit of England. The species ofwillow planted was chiefly one of those with broad leaves, woolly underneath(probably S. caprea L). The warmth of the situation, and the nidus for eggsafforded by these woolly leaves, were, I presume, the combined cause of theinsect being so remarkably attracted to this spot. Some of the plants wereof a species with smooth narrow leaves (probably S. triandra L.} : these es-caped much longer than the others, but still they did not escape eventually, asthey were also attacked by another caterpillar. I introduced both red andblack ants, and put some of the caterpillars into their nests; but the antsdisregarded them altogether. Having, although thus slowly, ascertained thetrue state of things, the ground was once more cultivated, and was plantedwith apple trees. As there happens to be no insect there which much attacksthese, they thrive very well. The distance at which apple trees are plantedis, also, less favourable to the propagation of vermin. I have communicatedall this detail in order to show the importance to individuals of attending tosuch seemingly trifling matters. Many a plantation, &c., fails in an apparentlyinexplicable manner. A scientific investigation would, in numerous cases,disclose the truth, and prevent farther loss. Had a person acquainted withentomology been proprietor of this osier ground 50 years since, he wouldspeedily have discovered the truth, and might have saved 200/. or more tohimself and his successors.” {Mag. Nat. Hist., vii. p. 423.)

The Chrysomela (Phae'do«) vulgatissima L. is another species which isoccasionally injurious to one of the narrow-leaved species of willow. This isa pretty little insect, of a shining blue or green colour, and of an oblong-ovalform, about £ in. in length, which is found, during the winter months, in greatprofusion under the loose bark of willows, growing in damp localities. Itdeposits its eggs upon the young leaves ; and the larvae, when hatched, formlittle associations, feeding together in regular rows, the heads of the second rowtouching the tails of the first. In this manner they proceed from the baseto the extremity of the leaf, which they soon strip of its parenchyma. Theythen attack the next leaf; and so on, until they are full grown, when theydescend into the earth, and assume the pupa state; shortly after which theyundergo the change to their last and perfect form.

The leaves of some species of willows are also infested with galls, whichare the production, not of a species of Cynipidae, but of one of the 2’enthredi-mdas (Nematus intercus Panzer Fauna Ins. Germ., 90. fig. 11.; or theTenthrbdo salicis pentandrse Villars). The larvae of this insect, instead offeeding externally upon the leaves of the willow, is enclosed in a gall, upon thesubstance of which it subsists, and within which it undergoes all its changes.Mr. Westwood’s species Nematus galiicola (described by Mr. Stephens, IUust.Brit. Ent., voi. vii. p. 36.), and the Euiira Cynips of Newman {Ent. Mag.,ho. 18. p. 260.), also reside in galls; whilst the larvae of Nematus salicis ofSaint Fargeau, and of the N. capreae, are external feeders.

Among the Lepidoptera , the caterpillars of nearly all the species of mothsbelonging to the genus Cerura (puss and kitten moths) feed upon differentspecies of willow; and also, occasionally, the larva of the buff-tip moth (Pygae'rabucephala Steph.). Brepha Parthenias (the orange underwing) feeds uponpoplars and willows; and Notodonta ziczac (the pebble prominent moth) uponthe same: Leiocampa dictae'a and L. dictaeoides (the swallow prominent moths),Htilodontes palpina (the pale prominent moth), Gastropacha quercifolia, &c.,occasronally upon willows; and the larva of Orthosis upsilon Steph. beneath

he bark of old willows and poplars.