October 12, 1871. ] 



JOUENAL OF HOKTICULTUKE AND COTTAGE GAKDENEK. 



279 



spirited away ! As an independent and non-oommissioned ob- 

 server, I venture to give an opinion regarding a few of the 

 prominent insect enemies wliieh have made the Hop their prey 

 this season, though I make no positive assertions with regard 

 to the state of matters in the midland districts, though, pre- 

 sumably, what applies to the south would not be inapplicable 

 to these. It is easy to catalogue a host of insects found on or 

 Bear Hop plantations, and yet far from easy to apportion to 

 ■each its due share of blame. I feel convinced that the prin- 

 oipal transgressors have been the aphides, alias flies, alias lice, 

 belonging to more than one species, though the " speciality " 

 ■of the Hop, Aphis Hamuli, ranks first ; for certain species 

 of plants have their particular enemies of the aphis genus, 

 though some of these flies appear to be migrate without mucli 

 discrimination. Indeed, Dr. Plimley, of Maidstone, has pro- 

 .pounded a singular theory with regard to the habits of the 

 Hop aphis. The hosts which cover the vines in May have 

 been produced, he asserts, from flies which have been fed up on 

 the Sloe. The autumn generation of this aphis, he thinks, 

 ■deposit their eggs in this plant, and their progeny, when 

 matured in the spring, take flight and settle in the Hop planta- 

 tions. If this be really the case, it would, perhaps, be ad- 

 visable to take measures for the extirpation of the Sloe or 

 Elaokthorn where it is growing wild in the hedges in those 

 districts; but, for my own part, I am at present dubious as to 

 t^is supposed fact. 



The fly, we say, frOm its rapid reproduction, and the diffi- 

 ■C'Ulty of dealing with it effectively, has always been an object 

 of the special dislike of the Hop-growers, yet many years ago 

 the veteran Kirby ventured to hint that they were somewhat 

 to blame, and might thank themselves for much of the trouble 

 and loss it caused them. Ha says, " Led by their old prejudices 

 O"! the fly being produced by cold wiuds, &c., they do nothing 

 towards ibs destruction, through, if aware of the way in which 

 it; is generated, and that by killing each female as it appears 

 early in the apring, they would prevent the birth, not of 

 thousands, but of millions of aphides. The aphides being 

 soft are killed with the slightest pressure, so that it is merely 

 necessary to rub an infested leaf between the thumb and 

 sSngers, with a force quite insufficient to in jure its texture, to 

 destroy every aphis upon it ; and from experiments which I 

 myself made in the Hop grounds of Worcestershire, when at 

 Malvern in 1838, I am persuaded that every leaf of each plant 

 might be thas cleared of the female aphides first attacking it 

 in spring by women or children mounted on step-ladders for 

 the purpose in ten minutes or less, so that six plants being 

 cleared per hour by one person, sixty might be cleared per 

 ■day. 



i do not enter into any discussion as to this plan, but make 

 ■the quotation oh'efly because there is, after all, something more 

 ■in the cultivator's idea about the " cold winds," whatever there 

 may be in the " &c.," than Kirby thought, though it need 

 iurnish no exease for slackening exertions. Aphides do not 

 benefit primarily by these winds blowing mostly from north or 

 east ; nor, again, do they suffer from them, as numerous other 

 ■Species of insects certainly must. Then how is it that they 

 increase so rapidly at such times? I am persuaded that it 

 is because those species which should prey upon them are 

 diminished in numbers, or rendered very inactive, by the un- 

 geuial infiaenoes of the season. Of the commoner species of 

 the genus Coccinella (the well-known lady-bird) there were 

 much fewer than usual in many places. Others, also, such as 

 the Syrphi, and the beautiful fly designated Chrysopa perla, 

 which are undoubtedly usefal in reducing the number of 

 aphides by means of their ravenous larvte, did not work with 

 their wonted diligence at this task, being backward in their ap- 

 .pearance. There is a dipterous insect that in SDme years 

 destroys many aphides, depositing eggs which produce a para- 

 aitie larva ; this was, I suspect, also lacking in ■vigour. And, 

 moreover, it must be borne in mind that aphides, though 

 ■eallous to many atmospheric influences, are now and then 

 severe sufferers by heavy rains in spring and early summer. I 

 iiave seen many of them lying drowned about their food-plants 

 at such times, and it so happened that at one or two periods 

 this year, when the aphides were multiplying rapidly, we had 

 a spell of dry weather. 



Bennie, many years ago, drew attention to the circumsiance 

 that about midsummer, or not very long afterwards, the plants 

 are gradually freed of their tormentors ; and a recent author 

 observes that the first indication of the approach of a favour- 

 able change is the clustering of the aphides at the extremities 

 of the leaves and twigs, while the lower leaves generally be- 



come almost clear of them. At this time, too, they cease to a 

 great extent to suck the juices of the plant. Then do they 

 migrate ? No ; modern entomologists of eminence think not, 

 and regard as erroneous the assumptions made by White, of 

 Sblborne, and others on this point. Occasionally aphides will 

 suddenly appear upon the Hop plants late in the season and 

 invade the flowers themselves. Under these circumstances it 

 sometimes happens that weakly plants are so severely injured 

 as to die ofi in the autumn. 



The small beetle called the " Hop flea," the Haltica conciuna 

 of most writers, does much harm in the spring ; in fact, it 

 infests the plants every spring in greater or less quantity, and 

 last season it was the pioneer of the insect host, attacking the 

 Hop at a very early stage in its growth. It has been supposed 

 to be most injurious in years when the nights are cold and the 

 days hot and dry, but this seems conjectural only. There is 

 much more probability in the opinion of those who trace a 

 connection between this insect and the manure applied to the 

 hills, and hence they recommend that the soil should be turned 

 up between the rows ; and Loudon says that if good stable 

 dung be used, and not littery dung, this insect is less trouble- 

 some, and the health of the plants is improved. " Prevention 

 is better than cure," no doubt, but where these beetles have 

 not been prevented from putting in an appearance they must 

 be swept off the plants or picked off. The application of lime, 

 under certain precautions, has been of much service, or the 

 fleas may be brushed through a tin funnel into a wine bottle, 

 out of which they cannot leap ; also it is suggested that they 

 may be captured by holding a large inverted bowl coated within 

 with gas tar just above the plant, to which the insects are to be 

 persuaded to leap up — a modification, in fact, of the "ketch 

 'em alive, oh !" plan, so pleasantly successful with flies. I 

 doubt whether the plan of covering the young plant with fine 

 earth at the time it is exposed to most danger is of marked 

 utility, though some have spoken in its favour. 



The wireworm I am not now about to touch upon, as I am 

 not able to throw any new light upon the history of the species 

 attacking the roots of the Hop. No doubt under this name 

 are comprehended the larvaj of several beetles, and centipedes 

 also, creatures of a very different nature. Modern researches 

 into the history of centipedes show that they resort to plants 

 and fruit chiefly for the sake of the insects upon them, yet 

 when young they are vegetable-feeders, taking to stronger ali- 

 ment as they grow older. 



Many lepidopterous larvse resort to the Hop. Hepialus 

 Hamuli feeds upon the roots of the Hop, also upon the Bur- 

 dock and Nettle. The larva lives through the winter, but 

 makes a nest for itself, remaining then in a state of torpidity. 

 That this species is materially injurious to the Hop has never 

 been proved. I have observed that in various localities 1 visit 

 about Loudon this moth, popularly called the Ghost, is much 

 scarcer than formerly. Dr. Withering recommended covering 

 the roots with stones as a preventive. Much more frequently 

 observed is the gay caterpillar of the Pale Tussock (Orgyia 

 pudibunda), which, though occurring often on the Hop, is a 

 very promiscuous feeder. A friend reports to me that in some 

 Hop gardens this year he saw quantities of the " Hop dogs," 

 as these caterpillars are familiarly called. The yellow pencils 

 of hair with which it is adorned, and the slashes of deep black 

 across the light green ground colour, render it conspicuous 

 enough, and it is accused of doing much more harm than is 

 really the case. The worst enemies of the Hop are not such 

 insects as these, which merely devour the leaves, but those 

 which, like the aphis, drain the plant of its vital juices, or 

 strike, like the wireworm, at the seat of life below. — J. E. S. C. 



PROPAGATION OP ECHEVERIA METALLICA 

 BY CUTTINGS. 



This striking plant is so useful in flower gardening for vari- 

 ous purposes, that there are few places now where more or less 

 of it is not seen. Strictly speaking, it belongs to the class of 

 fine or oharacteristio-leaved plants. Its leaves are more valu- 

 able for ornament than its flowers ; and to permit it to flower 

 is equivalent to wasting its beauty, for the foliage quickly falls 

 off in vigour and hue as the flower stem elongates, and the 

 whole plant becomes ungainly, and unfit for any ornamental 

 position. Large plants on one stem, with finely-developed 

 leaves, are beautiful objects in vases so placed as to be a little 

 under the eye ; and in higher positions they are striking in 

 appearance when contrasted side by side with softer and more 



