Cultivation is not only favourable to such old offenders, but it seems to have introduced entirely new ones; at least, the farmer now finds that wheat, clover, and other crops raised by rotation in the same fields, suffer injuries from insects, which, if they existed formerly, escaped notice. It may be, however, that the scientific spirit of late introduced into agriculture has only just discovered what in many cases has always been going on. At the same time, it is universally admitted that the destruction occasioned by insects is larger than ever it was, and that there are insects at work in the fields which were little, if at all, known to our forefathers.
One very good reason for the progressive increase of agricultural plagues is that they multiply proportionately at a much quicker rate than the plants on which they feed. We are actually rearing them artificially, and the problem is how to cultivate crops without at the same time cultivating these parasites. High-farming, by pampering plants, no doubt renders them more delicate and more liable to attack; but perhaps we help to make our own trouble by not exercising ordinary caution. Certain it is that destructive insects are imported into, as they are exported out of, this country. The agricultural produce which we bring from various parts of the world must contain many unwelcome visitors, though, fortunately, our climate does not agree with the majority of them. Like the famous Colorado Beetle, even if allowed a fair chance, they would scarcely thrive. Others there are with the Scotsman’s reputation of being able to do well anywhere. They only require a suitable plant to feel perfectly at home. They sometimes get ‘assisted’ emigration at the cost of their favourites, like the hop aphis, which was introduced into America among hop-roots sent from England. The former country has by entomologists been styled ‘the home of insects;’ but, to Europe’s loss, one highly interesting though destructive American crossed the Atlantic—namely, the phylloxera, so destructive to vines. An individual that undergoes various puzzling transformations is not readily identified, and the hop aphis, having these disguises, has alarming opportunities of getting a footing where it is least wanted. Indeed, all such destructive insects should receive more study than they have hitherto obtained. Within the last few years, scale insects were introduced into the Californian orange groves from Australia; and orange, citron, and lemon growers in other parts of the world are now complaining of pests of a similar nature. Considering the evil which has been already accomplished, it is highly important that farmers, fruit-growers, gardeners, and all who cultivate the land should be made acquainted with all that is known regarding the insects which attack their several crops.
The hop-plant in particular has many enemies, some of them so destructive, that if not checked, they would soon ruin the grower. Within the last thirty years, it is believed the liability of this plant to attack by insects has considerably increased. Hop-planters assert that insects now destroy their crops which were not known in the plantations until recently. Mr Whitehead selects ten of the most troublesome species, and gives descriptions of each insect, together with its life-history, its modes of attack, and the injury to the hop resulting therefrom; also a detailed account of methods of prevention, and of measures which have been found efficacious in stopping or alleviating these attacks.
Mr Whitehead originally intended to confine his second Report to insects injurious to corncrops; but as the work progressed, it was found desirable to include those destructive to grasscrops, as some insects are common to both. While dealing with cereals, he also thought it well to treat pulse, under which title are included plants such as peas, beans, and tares, and to describe the principal insects which affect them, especially as they are all crops liable to be attacked by the same insects. A description of a genus the most injurious to different kinds of clover, is also given. To include comparatively harmless insects in a work which is intended not so much for scientific purposes as to enlighten farmers and others regarding the pests which molest them most, was not necessary. For sufficient reasons it has been found most expedient neither to arrange them alphabetically nor according to a recognised scientific classification, but to take the insects of each group as far as possible in the order of their injurious effects. Indeed, there are included what, in the scientific acceptation of the term, are not insects at all. But the Report was written to convey useful and practical instruction to the cultivators of the soil, and wisely it was done in the manner which was likely to benefit them most. ‘With regard to these’ (the chief pests), Mr Whitehead writes, ‘it has been endeavoured to collect all the information that is known about them, and to bring this down to the latest date. It is believed that each monograph is a résumé of all that is known of its subject, of its life-history, and the means of prevention, and remedies against it. It is admitted that in several instances the information is still imperfect; and in compiling this series of Reports, I have been more than ever impressed with the necessity of enlisting skilled workers in this cause, as well as of urging and encouraging habits of observation amongst those who superintend the cultivation of the land and those who work upon it.’
A NURSE.
A nurse, a simple nurse; to the unthinking
Only a nurse, and nothing but a name:
A patient woman in her round of duty,
Living and dying all unknown to fame.
Only a nurse, a messenger of mercy,