192 



CULINARY OR KITCHEN GARDEN. 



is convex above, and pretty deeply punctured ; 

 the wing-cases are much wider than the thorax, 

 likewise thickly and irregularly punctured, each 

 of them with a pale-yellow or slightly sulphur- 

 coloured stripe running along the middle, curved 

 inwards posteriorly, and not reaching quite to 

 the extremity ; the under side of the body and 

 thighs black ; all the tibiaa and tarsi of a pale 

 hue. This little insect feeds on the turnip, 

 which it attacks both in its perfect and larva 

 states. When the plants have acquired some 

 degree of strength, and the fohage is consider- 

 ably developed, the injury done by it is insigni- 

 ficant; but, unfortunately, its favourite food is 

 the young plant, just as it is beginning to un- 

 fold its cotyledon leaves. These it consumes 

 with the utmost avidity, both as a larva and 

 a full-grown insect ; and where it abounds, the 

 field is often wholly stripped of its crop in a 

 very short time. Indeed, their powers of mas- 

 tication are surprising for creatures of so small 

 a size. They are found to attack the turnip 

 plants as soon as the latter make their appear- 

 ance ; and one of the difficult points to deter- 

 mine is, how they are produced so speedily 

 and so opportunely. In regard to the turnip 

 saw-fly and lepidopterous insects the process is 

 obvious, the eggs being laid upon the plant by 

 the parent fly, and the larvse evolved more or 

 less speedily, but after the lapse of some consi- 

 derable time. The appearance of the plant and 

 insect being in the present case almost simul- 

 taneous, it has been thought difSoult to con- 

 ceive how the same process should be gone 

 through." — Quarterly Journal of Agriculture, 

 vol. viii. p. 353. Various conjectures have been 

 formed to account for the early appearance of 

 this insect on the turnip plant. "But these 

 conjectures," continues Mr Duncan, " may now 

 be referred to merely as matters connected 

 with the past history of this insect, and as 

 showing the difficulty that has been experienced 

 in tracing it throughout its diflerent forms and 

 changes. This, however, has been recently done 

 by Mr H. Le Keux, and we are no longer in 

 doubt as to the points alluded to. This ob- 

 server found that the sexes pair from April to 

 September, during which period the eggs are 

 deposited on the under side of the rough leaves 

 of the turnip. The female insect does not ap- 

 parently lay above one egg daily ; in a week ten 

 pair are found to lay only forty-three eggs. 

 These eggs are very minute, smooth, and partak- 

 ing of the colour of the leaf. They are hatched 

 in ten days ; the maggots (fig. 66) are an eighth 

 of an inch long, pale, fleshy, and eyhndrical, with 

 six pectoral feet; the eyes dark, and a dark 

 patch on the first and last segments of the body; 

 they immediately eat through the lower skin 

 or cuticle of the leaf, and form winding burrows 

 among the pulp, upon which they feed. The 

 thickness of the leaf is sufficient to afford them 

 ample scope for this, and they may be seen at 

 work in their galleries by holding the leaf up to 

 •the light. These maggots or larvas are full fed 

 in sixteen days, when they bury themselves in 

 the earth not quite 2 inches under the surface, 

 selecting a spot near the bulb, where the turnip 

 leaves protect them from wet and drought ; 



they enter upon their chrysalis state in the' 

 earth, and the beetle emerges in about a fort- 

 night. About thirty days carry the insect 

 through all its diflerent stages, and of these ten 

 are passed in the egg state, six as a maggot, and 

 fourteen in the chrysalis. There appear to be 

 five or six broods in the season." — Transac- 

 tions of the Entomological Society of London, 

 vol. ii. p. 24. 



On this subject Mr Stephens, in "Book of 

 the Farm," vol. ii. p. 74, makes the following 

 sensible remarks on the economy of such in- 

 sects, and also on the remedial measures that 

 might be adopted for their suppression : " In 

 the case of those insects which feed on the 

 foliage of plants in their larva state, and after- 

 wards derive their aliment from other sub- 

 stances, the general law seems to be that a 

 much longer duration is assigned to the larva 

 than to the perfect insect ; and it may be that 

 this is not observed in regard to such as always 

 consume vegetables, because in either of these 

 conditions they serve the same purpose in the 

 economy of nature, to which the prolonged ex- 

 istence of the larva bears reference in the other 

 instance. Parallel examples are of frequent 

 occurrence amongst insects. Unless the eggs 

 of the common fiesh-fly were hatched with ex- 

 treme rapidity, the larvae, when they appear, 

 would neither obtain their food in perfection, 

 nor fulfil the useful purposes for which they are 

 now subservient. The remedies against the 

 attacks of this insect," Mr Stephens fears, " are 

 of a hopeless character ; at least, it is better to 

 prevent their appearance than to wage war 

 against them when they do appear, as, even in 

 the efforts to eflect their destruction, the culti- 

 vator is the chief sufferer." The preventive 

 measures, Mr Stephens thinks, are to keep the 

 ground clear of weeds, particularly those of the 

 cruciferous order, which are especial favourites 

 with this beetle, to sow in drUls instead of 

 broadcast, " and to sow the seed thick and of 

 the same age, for it is found the more rapidly 

 the plants grow at first, they are the less often 

 attacked; to put the seed for some time before 

 it is sown amongst flowers of sulphur, and sow 

 the sulphur amongst it." This latter is, we 

 know from several years' experience, u, very 

 great check to this insect, and, indeed, to all 

 others that attack the CruoifersB. We have 

 little faith in brushing the insects off the plants, 

 as they have the means of taking possession of 

 them very shortly afterwards: dusting with hot 

 lime, and watering with lime-water, applying it 

 with force, are the best remedies we have tried. 

 For years we held a strong opinion on the advan- 

 tages of sowing turnip-seed of several ages, believ- 

 ing that the insect would seize upon and devour 

 the crop which first germinated, and which would 

 be from the seed of the previous season's 

 growth ; and that by the time the older seeds 

 had germinated, the brood would have changed 

 into another state ; and such, no doubt, might 

 be the case, if the insects were all produced at 

 once, or from one hatching of the eggs. Subse- 

 quent observation, however, has convinced us 

 that this is not the case, but that brood after 

 brood is hatched ; and severail germinations of 



