INJUllIOUH TO TUK TURNIP CitOP. S8S 



Unee when dissatisfted witli its position. On being first removed from its 

 cell, it moves its littlo cibarian instruments with great rapidity ; and emita 

 from its mouth a considerable <]^uaniity of a light brownish fluid. This may, 

 perhaps, be a preservative provision to annoy its enemies, and may likewise 

 oe employed as an irritant to divert the sap to form the curious excre»- 

 oenoes under which it resides. Ou being extracted, it will again speedily 

 bury itself within the substance of the turnip. It is quite similar, if not 

 quite identical, with the grubs found in galls on the stems of cabbages ; but 

 it is yellower, and I do not find the spots on the breast and terminal seg- 

 ment of the latter. Specimens, however, quite the same with those on cab- 

 bages and greens, I have found in ihe mid-rib of the leaf, and near the top 

 of the bulb of young turnips. I have not, as yet, reared any of them, bat 

 I have, in several instances, taken from the soil about the roots of greens 

 infested with the disease, Nedyiit (Ceutorhpichus) gulcicoUitf in an immature 

 state, the same species to which " fingers-and-toes" is ascribed. The pupa 

 is naked, soft, and white, and, unlike those enclosed in a case, might be 

 destroyed bv a slight exposure to frost. It is liable, while in the gall» 

 to become the prey of a small black, reddish legged, parasitic Ichneumon, 

 which, on leaving the grub, envelopes itself in a loose hempen-like coccoon. 

 On the cabbage, and in the few instances wherein 1 have observed it, like- 

 wise on the turnip, it commences its operations on the mid-rib of the leaves. 

 Originating under a small green wart, caused, probably, by the puncturing 

 of the parent insect preparatory to the deposition of its egg, it makes its 

 way to the centre, along which it eats a channel in either direction, emerg- 

 ing occasionally, if one may judge from the opening of its little tunnel 

 outwards. It probably settles finally in the roots, but I have not, as yet, 

 followed its progress thither. As it is the outer leaves that are principally 

 affected, these might be pulled off as soon as symptoms of decay appear. 

 Another smaller and more linear species, with two sub-corneous brownish 

 patches about the middle of the prothorax (second segment), is sub-cut- 

 aneous in the cabbage leaves. The clubbing of the cabbage stem takes 

 place principally on the part immediately under the soil, and the swellings 

 seldom come into contact with the roots. The grub does not penetrate very 

 deeply, and may be readily removed with a knife ; and it is to be observed 

 of the turnip galls, that they are likewise somewhat superficial. In both 

 instances, the grubs continue to tenant the galls during the winter. Most 

 of them had deserted the stems of greens in June, but a few remained still 

 later. From this, it would appear, that the readiest way of diminishing the 

 insects would be, to remove the old plants from the soil as early as pos- 

 sible in the season, and that they should be disposed of in such a way as to 

 prevent the insect from entering into the ground to undergo its final trans- 

 formation. My object, however, in adducing these facts, is not so much 

 for the sake of practical remark, as to shed light on a little understood 

 disease. So far, then, as my observations go, the effects of grubs of the 

 weevil on cabbages and turnips are precisely alike; they form surfltee 

 galls, but they do not account for the protuberances and distortions that 

 are constantly being generated in the turnip bulb and roots. That the 

 grubs, if numerous, would cause an aggregation of tubercles to rise roand 

 the bulb, that may materially interfere with its increase in sire, or that 

 may even prevent any bulb from being produced at all, I have seen facts 

 to prove ; but this differs very considerably from the abnormal tendency 

 to form a continual repetition of monstrous growths, which, from its occur- 

 rence only on particular soils and in special circumstances, may be more 

 justly viewed as a consequence of these pernicious external influences, 

 Proressor Johnston mentioned before the Agricultural Chemistry Associa- 

 tion a somewhat similar disease, as occurring at Pinkiehill, in a moonr toil, 

 containing a considerable proportion of manganese, which operated tojori- 

 ously on the turnips grown on it. He described the disease as consisting 

 in a ** large fungus or wart, that gradually reached the head of the turnip 

 and destroyed it;" which, indeed, is one of the many symptoms that char- 

 acterise " fingers-and-toes." It woxild thus appear, that there may be two 

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