Augnst 29, 1872. ] 



JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 



165 



•with the French jacque, a coat of mail, alluding to the tough 

 wing-eases of the insect ? 



It has often been a matter of wonderment from whence 

 the insects suddenly appear in early spring, and pounce upon 

 the seed-lobes of the Turnips immediately upon emergence 

 from the earth ; and authorities differ as to whether they pass 

 the winter in the pupal stage, or whether they have lived 

 through it as beetles in a semi-torpid condition. However, 

 they are lively enough, and very voracious, just, unfortunately, 

 at the time when the plant has quite enough to do to hold its 

 own without having to withstand an attack of this kind. 

 Later in the season (for there seems to be a succession of 

 these insects upon the crops), of course, a minor degree of 

 injury is produced. The history of H. nemorum has been 

 made in some measure obscure from the circumstances that 

 both the larva and beetle prey upon the Turnip, and authors 

 have not been always sufficiently careful in explaining to which 

 they were referring. The beetles or " fleas " are to be found 

 from April to September ; the larva? are most frequently ob- 

 served in May and June ; but the habits of the species in these 

 two conditions are markedly different. There can be no ques- 

 tion that the beetle is the worst enemy, since it is this which 

 will, if unchecked, entirely destroy in some years two or three 

 successive sowings in the spring. 



If we pick up one of these and examine it with a pocket 

 glass, we see at once, from the appearance of the wing-cases, 

 that it is undoubtedly true that the insect is not hurt by con- 

 siderable pressure, and we can understand how it can, if it 

 wishes, enter the earth. The elytra, or wing-cases, are both 

 elastic and strong, rather glossy, with minute punctures 

 scattered over them, and a well-marked pale stripe in the 

 middle of each. The thorax, which is narrow, is also punc- 

 tured, and of the same dark hue as the wing-cases. The 

 ■whole length is hardly one-eighth of an inch. One naturalist 

 has stated that the work of egg-laying goes on slowly, for it 

 was observed that ten pair in the course Of a week only laid 

 forty-three eggs ; but if this calculation was made with speci- 

 mens in confinement, it is of little value, the rate of oviposi- 

 tion being always modified under an unnatural constraint. It 

 is certainly probable that the total number laid by each indi- 

 vidual is not large, but from the mode of life of the young 

 larva? they escarm perils which beset some when very juvenile. 

 These mine the leaves of the Turnip, forming tracks in the 

 parenchyma or pulp, which are often tortuous. It has been 

 asserted that they are full-grown in about sixteen days — a rate 

 of growth which is presumably exceptional, and occurring 

 only under very favourable circumstances. When adult they 

 descend to the earth, and, with singular instinct, choose a 

 temporary resting-place at the root, where they are best pro- 

 tected from rain, and also excessive heat. The larvse or 

 ■" grubs " have the usual characteristics of those of their 

 order, being of a dull flesh colour, with dark eyes and two 

 dark patches on the head and the last segment of the body. 

 The feet are six in number, and supplied with muscles very 

 helpful to the larvas in their work of burrowing. 



There is much force in the assertion of Stephens, that it is 

 better to prevent the appearance of the " flea " than to wage 

 war against it. But how ? A dry season is favourable to this 

 insect — so much we know, and hence artificial waterings have 

 been found efficacious in keeping it off, or in diminishing its 

 numbers, when natural showers were withheld. No doubt as 

 much stimulus as can safely be given to the Turnip at an early 

 stage is quite advisable, since the more vigorous the plant the 

 less it suffers from the attacks of this beetle. Steeping the 

 seed as a preventive has been highly recommended by some, 

 and as absolutely rejected by others. Mcintosh advises us to 

 put the seed in sulphur before sowing, and afterwards to 

 sprinkle sulphur on the earth ; and it has been proved that 

 the application of spirits of tar or gas lime soon after sowing 

 is very disagreeable to these beetles. The scheme of sowing a 

 quantity of seed of different ages turned out a failure. Ac- 

 cording to this idea, the first which would germinate being the 

 seed of the previous season, the insects, it was thought, would 

 prey upon this, and leave untouched the crop which rose from 

 the older seeds. In actual practice, however, it was discovered 

 that a succession of "fleas" made their appearance just as 

 each growth of Turnips was in the condition that suited them 

 best, so thereby nothing was gained. 



This beetle has its parasites of insect nature, and also serves 

 as food for various birds. Turning out poultry, in order that 

 they may prey upon them, has been found a rather "risky" 

 plan, as any knowledge of gardening they possess is theoretical, 



and is never allowed to interfere with their practical researches 

 for food. 



More active measures for the destruction of the Turnip 

 flea tend mostly to the removal of the insects from the plants 

 by sweeping or otherwise. Where the space on which the 

 operation has to be performed is but limited, a piece of cloth 

 smeared with some adhesive compound is attached to a handle 

 and drawn backwards and forwards among the young plants. 

 Dusting them with lime or charcoal is a common and not un- 

 successful expedient. It need hardly be said that fumigation 

 is inapplicable. Trenching the ground deeply in winter has 

 been advised. In a report written by Messrs. Hardy and Lang- 

 lands respecting the ravages of this insect in the north of 

 England during 1870, it is stated that in a field where wild 

 Mustard had sprung up it rendered much service by withdraw- 

 ing the "fleas" from the young Turnip plants; and Mr. 

 Hardy adds that he has heard of similar instances, though 

 weeds of the Cruciferous order, especially Cardamine, have in 

 other cases helped to nurture the species and bring it forward, 

 so that it is advisable to eradicate these in the vicinity as far 

 as possible. The observer just quoted remarks that the 

 patches of waste ground, " if they do not furnish all, yet help 

 to augment the hosts of ' fleas ' which invade the cultivated 

 lands." According to Eirby, a service similar to that rendered 

 by the Sinapis arvensis was noticed by him to be effected by 

 Brussels Sprouts, about which some patches of young Turnips 

 were sown, and nearly all the Haltica? were drawn off from the 

 latter. Giving an account of the injury produced by the 

 Turnip flea in Northumberland in 1870, Mr. Langlands points 

 out that though it was more abundant than he had ever seen 

 it, the plants sustained the greatest damage later in the season 

 than usual, and after they had survived the perils of early 

 growth. 



A congener of Haltica nemorum, by name H. fuscicornis, 

 did much damage in the neighbourhood of Newbury and some 

 other districts to the young plants of Saintfoin, as recorded in 

 the " Entomologist " of April, 1871. The beetles pursued the 

 same plan as do the enemies of the Turnip, fastening them- 

 selves upon the cotyledons and first leaves as soon as they 

 appear. In this species the head and thorax are of a dingy 

 red colour; the wing-cases, which are shining, are dark green, 

 shading into black in some specimens. The insect was known 

 to Linna?us, and is described by him ; but is much better 

 known by the name of rufipes, given by De Geer, and adopted 

 by the English entomologists of last century. 



Since my paper was written in which some account was 

 given of a new pest found upon the Vine (Peritymbia Yitisana) , 

 my attention has been called to a report of a meeting of the 

 Scottish Meteorological Society, in which it is stated that in 

 the course of a discussion on the bearing of meteorological 

 science upon farmers, it was suggested that this insect was 

 probably transported hither from America in the first instance, 

 and the mode indicated was by means of a journey through 

 the air, the strong westerly winds being accused of conveying 

 the spores (or eggs ?) across the ocean. I suspect this theory 

 will be discovered to be baseless, though it is quite probable 

 the species might have travelled from the New World to the 

 Old, but in a different way, attached to some material object 

 on terra firma. It must also be remembered, that it does not 

 follow of necessity because an insect suddenly appears in pro- 

 fusion where it had not been observed before, that it must 

 have been imported to the country. Other explanations are 

 possible and plausible. — J. R. S. C. 



Sensation in Plants. — M. Figuier believes that a plant has 

 the sensation of pleasure and of pain. Cold, for instance, he 

 says, affects it painfully.- We see it contract, or, so to speak, 

 shiver under a violent depression of temperature. An abnor- 

 mal elevation of temperature evidently causes it to suffer, for 

 in many vegetables, when the heat is excessive, the leaves 

 droop on the stalk, fold themselves together, and wither ; when 

 the cool of evening comes, the leaves straighten, and the plant 

 resumes a serene and undisturbed appearance. Drought causes 

 evident suffering to plants, for when they are watered after a 

 prolonged drought they show signs of satisfaction. The Sensi- 

 tive Plant, touched by the finger, or only visited by a current 

 of unwelcome air, folds its petals and contracts itself. The 

 botanist Desfontaines saw one which he was conveying in a 

 carriage fold its leaves while the vehicle was in motion, and 

 expand them when it stopped — a proof that it was the motion 

 , that disturbed it. Sensation in plants is of the same kind as 



