chap. cm. salica\:e;e. sa'lix. 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 disap- 

 peared. " My attention," says the writer, " being now strongly drawn to the 

 subject, I discovered that which I ought to have perceived half a century 

 sooner ; namely, that Nematus capreae, favoured by the peculiar locality, was 

 the cause of all this devastation. The spot is low, moist, shut in by wood, 

 and very near the southern limit of England. The species of willow planted 

 was chiefly one of those with broad leaves, woolly underneath (probably 

 S. capreaZ/.). The warmth of the situation, and the nidus for eggs afforded by 

 these woolly leaves, were, I presume, the combined cause of the insect being 

 so remarkably attracted to this spot. Some of the plants were of a species 

 with smooth narrow leaves (probably S. triandra L.) : these escaped much 

 longer than the others, but still they did not escape eventually, as they were 

 also attacked by another caterpillar. I introduced both red and black ants, 

 and put some of the caterpillars into their nests ; but the ants disregarded them 

 altogether. Having, although thus slowly, ascertained the true state of things, 

 the ground was once more cultivated, and was planted with apple trees. As 

 there happens to be no insect there which much attacks these, they thrive 

 very well. The distance at which apple trees are planted is, also, less favour- 

 able to the propagation of vermin. I have communicated all this detail in order 

 to show the importance to individuals of attending to such seemingly trifling 

 matters. Many a plantation, &c, fails in an apparently inexplicable manner. A 

 scientific investigation would, in numerous cases, disclose the truth, and pre- 

 vent farther loss. Had a person acquainted with entomology been proprietor 

 of this osier ground 50 years since, he would speedily have discovered the 

 truth, and might have saved 200/. or more to himself and his successors." 

 (Mag. Nat. Hist., vii. p. 423.) 



The Chrysomela (PhaeMorc) vulgatissima L. is another species which is 

 occasionally injurious to one of the narrow-leaved species of willow. This is 

 a pretty little insect, of a shining blue or green colour, and of an oblong-oval 

 form, about £ in. in length, which is found, during the winter months, in great 

 profusion under the loose bark of willows, growing in damp localities. It deposits 

 its eggs upon the young leaves; and the larvae, when hatched, form little asso- 

 ciations, feeding together in regular rows, the heads of the second row touching 

 the tails of the first. In this manner they proceed from the base to the extre- 

 mity of the leaf, which they soon strip of its parenchyma. They then attack 

 the next leaf; and so on, until they are full grown, when they descend into 

 the earth, and assume the pupa state ; shortly after which they undergo the 

 change to their last and perfect form. 



The leaves of some species of willows are also infested with galls, which are 

 the production, not of a species of Cynipidae, but of one of the Tenthredfnidae 

 ( Nematus intercus Panzer Fauna Ins. Germ., 90. fig. 11. ; or the Tenthredo 

 salicis pentandrae Villars). The larva of this insect, instead of feeding exter- 

 nally upon the leaves of the willow, is enclosed in a gall, upon the substance 

 of which it subsists, and within which it undergoes all its changes. Mr. West- 

 wood's species Nematus gallicola (described by Mr. Stephens, ///z^. Brit. Ent., 

 vol. vii. p. 36.), and the Enura Cynips of Newman (Ent. Mag., No. 18. p. 260.), 

 also reside in galls; whilst the larvae of Nematus salicis of Saint Fargeau, 

 and of the N. capreae, are external feeders. 



Among the Lepidoptera, the caterpillars of nearly all the species of moths 

 belonging to the genus Cerura (puss and kitten moths) feed upon different 

 species of willow; and also, occasionally, the larva of the buff-tip moth (PygaeYa 

 bucephala Steph.). Brepha Parthenias (the orange underwing) feeds upon 

 poplars and willows ; and Notodonta zfczac (the pebble prominent moth) upon 

 the same: Leiocampa dictae v a and L. dictaeoides (the swallow prominent 

 moths), Ptilodontes palpina (the pale prominent moth), Gastropacha querci- 

 folia, &c, occasionally upon willows ; and the larva of Orthosk upsilon Step/?. 

 beneath the bark of old willows and poplars. 



