1116 



PRACTICE OF AGRICULTURE. 



Part III. 



of a singular speciee of rooth, named by collectors the ghost. The vegetable diseases incident to the hop 

 are, the honey-dew, the mould, the blight, and the fire-blast, all of which take place at different times, 

 though mostly when the plant is full grown. 



appearance towards the end of May, and during the two next 

 months. These insects propagate so prodigiously, that when- 

 ever they have once made a settlement upon a hop plantation, 

 they seem to have baffled every art of man, either to extirpate 

 them, or even to check their increase. It is a vulgar error to 

 suppose that they come or are carried away by any particular 

 wind ; or that mildly warm weather will affect their removal. 

 It is true, that on such days the perfect insects are seen on the 

 wing ; but it is only to extend their destructive race to other 

 plantations, and to establish new colonies. Sudden and vio- 

 lent showers of rain, or gusts of wind, causes the death of mil- 

 lions ; and vast quantities are devoured by sorrows and other 

 small birds ; yet these are accidental and insufficient palliatives. 

 It is, therefore, strongly recommended, that the process de- 

 scribed by Curtis, of throwing pulverised lime by the instru- 

 ment he used, be tried on hops infected by the A'phis ; and we 

 venture to predict that it would be attended with considerable 

 success. 



7674. The ghost moth (Hepialus htimuli F.) deposits its eggs 

 near the roots of the hop plant, upon which the larva or 

 caterpillar feeds, sometimes doixig them considerable injury. 

 The best preventive is to destroy the moth, and this may be 

 done by attracting it at dusk to a candle and lantern, carried 

 by a boy over the grounds, who could knock down very many 

 with his hat. The moth is of a tolerable size ; and one sex is 

 entirely white, so that it may be seen, even at night, with ease. 

 It hovers over a small spot of ground, so that a good catcher 

 of insects might clear the plantation in a few evenings. In 

 1826 the ghost moth appeared in many parts of Warwickshire, 

 in very considerable numbers. 



7675. Clover is very subject to be injured by a very small weevil (A'^pion flavifemor5.tum K.), which at 

 all seasons feeds upon the seed of the purple clover, while another species of the same tribe (A. flavipes) 

 devours that of the white or Dutch clover; the injury, unfortunately, cannot be known while the plants 

 are growing, as they have then every appearance of being perfectly healthy. The young shoots of the 

 purple clover are often devoured by the same little jumping beetles (Haltica jP.) which attack both turnips 

 and hops. 



7676. Pastures in general are often destroyed to a very great extent by the larva or grub of the cock- 

 chafer (970. a), known in different parts of England by the following provincial names : Brown tree-beetle, 

 blind beetle, chafer. Jack horner, JeffVy cock, May. bug, brown-clock, dor, and miller. 



7672. The hop insect, improperltj called thejlea, has no other 

 resemblance to that animal, than that it is small, and jumps. 

 It is, on the contrary, a beetle (H^ltica concfnna), of a species 

 closely allied to that which infects young turnips. In its per- 

 fect state it commits great havoc, by eating the tender shoots 

 of the young plants. It has been said, that this insect abounds 

 most in seasons when the nights are cold, and the days hot 

 and dry. Others assert, that it is most frequent on plants in 

 grounds that have been dunged the same year, on which ac- 

 count it has been recommended, that the manure used for 

 covering the hills should be previously well mixed as before 

 directed (6019.), and applied either over all the land, or only on 

 the hills ; but this and various other plans do not appear to 

 have originated in a due knowledge of the subject. Nothing 

 as yet appears known regarding the nature or habitation of 

 this insect in its larva or grub state ; and unless it is ascer- 

 tained to live, during that period, in manure, the above plan 

 will inevitably prove abortive. The deadly effects of lime upon 

 insects, however small,has been extensively proved, and should 

 be resorted to in all cases where the expected value of the crop 

 will bear the expense of its application. Mr. Samuel Curtis 

 has stated in the Horticultural Transactions (vol. 6. part 2. 

 p. 124.) the very great advantages he has derived by applying 

 pulverised quick-lime to fruit-trees ; and there is no doubt that 

 the same remedy would be equally successful if extended to the 

 turnip and hop plants, so soon as the young leaves begin to ap- 

 pear, or on the first symptom of their being attacked by this 

 insect. 



7673. The hop louse, called by some the green or long-winged 

 fly, is a species of A 'phis peculiar to the plant ; it makes its 



7677. Tht ravastt of the larva are even ex- 

 ceeded by those of the perfect insect, which 

 sometimes appears in this country in prodi- 



gious multitudes, and, like a flight of locusts, 

 devour every green thing on the face of the 

 earth. The eggs of this terrible devastator are 

 white, and are deposited in the ground, where 

 they soon change into a soft whitish grub with 

 a red head, and about an inch and a half 

 long (i). In this state it continues four years, 

 during which time it commits most destruc- 

 tive ravages on the roots, not only of grass, 

 but of all other plants and young trees. Whole 

 acres of the richest pastures are thus rendered 

 unproductive; all verdure is lost, and the 

 tan will roU up almost with as much ease as 

 if it had been cut with a spade. The whole 

 of this injury being carried on under ground, 

 admits neither of preventive nor palliative 

 measures ; but the destruction to be expected 

 from the perfect insect may yet be prevented. 

 If the dried and withered turf is now re- 

 moved, the soil underneath will appear turned 

 into a soft mould for about an inch in depth, 

 like the bed of a garden ; in this will be 

 found the grubs, lying on their backs in a curved position, 

 and vast quantities may be gathered and given to pigs and 

 poultry. When full grown, the larvce dig in the earth to the 

 almost incredible depth of five or six feet, spin a smooth case, 

 and then change into a chrysalis. In this inactive form thev 

 remain until the following spring. 



7678. The perfect insect or beetle then comes from the ground, 

 and commences an immediate attack upon the leaves of all 

 trees. Their numbers are sometimes so immense, that, was 

 not the following account fully authenticated, we should al- 

 most doubt its correctness : In 1688, the cockchafers appeared 

 on the hedges and trees in the county of Galway in clusters of 

 thousands, clinging to each others' backs in the manner of 

 bees when they swarm. During the day they remained quiet, 

 but towards sunset the whole w ere in motion, and the humming 

 noise of their wings sounded like distant drums. Their num- 

 bers were so prodigious, that for the space of three miles they 

 darkened the air ; and the noise they made in devouring the 

 leaves was so loud, as to have been compared to the distant 

 sawing of timber. In a very short time the leaves of atl the 

 trees for some miles were destroyed, leaving the whole country, 

 in the middle of summer, as naked and desolate as it would 

 have been in winter. Swine and poultry devoured them in 

 vast quantities; they waited under the trees for the clusters 



dropping, and became fat upon this unusual food : even the 

 lower orders of the people, from these insects having eaten up 

 the produce of the earth, adopted a mode of dressing them, 

 and used them also as food. Towards the end of summer they 

 are said to have suddenly disappeared ; and we have no account 

 of their having been seen in any considerable numbers the fol- 

 lowing year. (Phil. Trans, xix. p. 743. &c.) These grubs did 

 so much injury about seventy years ago to a poor farmer near 

 Norwich, that the court of that city, out of compassion, allowed 

 him 25/. ; the man and his servant declaring that they had 

 gathered eighty bushels of these beetles. The best, andindeid 

 the only effectual remedy for the destruction of the perfect in- 

 sect, is to shake the trees or bushes at noon, when they are 

 either asleep, or in a state of stupor, and then to sweep or gather 

 them up. One person in this way has been known to capture 

 a thousand in a day, which, on a moderate calculation, pre- 

 vented no less than one hundred thousand eggs from being laid. 

 Some judicious farmers plough the ground when they have 

 reason to think it is infested by the grub, and this is generally 

 indicated by the rooks attempting to reach them. They are 

 also greedily devoured by crows, magpies, and jays, whose sole 

 employment, for nearly three months in the spring of the year, 

 is to search for insects of this sort ; and the destruction they 

 cause among them is above all calculation. 



7679. Cabbages and other esculent vegetables are well known to be greatly injured by the caterpillars of 

 two different kinds of white butterflies {fig. 971.), one of these (Pieris br&ssice,c) is much larger than the 

 other : the caterpillar is pale yellow, with black spots (a) : when full fed, it shelters itself on walls, pales, or 

 trunks of trees, and changes into the chrysalis state (6), in which it still preserves the same cast ot 

 colouring : the perfect insect (c) appears early in spring, and continues until the end of summer. The other 

 species of caterpillar is green {d) ; the chrysalis (e) is of the same colour ; and the butterfly (/) is produced 

 about the same time as the preceding. Various methods have been recommended to prevent the winged 

 insect from depositing its eggs upon those plants which nature has given them the instinct to select ; these 

 are, however, ineffectual, and in many cases sufficiently ridiculous : handpicking the larva, and searching 

 for the chrysalis, are the only plans we can recommend, either for these or the gooseberry and currant 

 caterpillars. 



7680. Fruit trees of all kinds, and their produce, are attached and devoured by a great variety of insects, 

 an enumeration of which will be found in our Encyclopaedia of Gardening. We shall, however, advert to 

 those curious minute insects ( TTirips Physapus,^^. 972. /, h) so often seen in flowers and blossoms during the 

 spring, and which, in their natural size (/), appear like short black lines. Nearly all fruit trees are liable 

 to considerable injury fpom different species of C6ccus or cochineal insects. They are mostly so small 



